Input Formats and Specifications of the National
Geodetic Survey Data Base
Volume I. Horizontal Control Data

Silver Spring, MD 20910 
September 1994 












U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Coast and Geodetic Survey
Input Formats and Specifications of the National
Geodetic Survey Data Base
Volume I. Horizontal Control Data


RADM J. Austin Yeager, NOAA
Chairperson, Federal Geodetic Control Subcommittee
Federal Geodetic Data Committee

Silver Spring, MD 20910 
September 1994









U.S. DEPARTMENT OF COMMERCE
Ronald H. Brown, Secretary

National Oceanic and Atmospheric Administration
Dr. D. James Baker, Administrator

National Ocean Service
Dr. W. Stanley Wilson, Assistant Administrator 

Coast and Geodetic Survey
RADM J. Austin Yeager, Director                             PREFACE

"Input Formats and Specifications of the National Geodetic Survey
(NGS) Data Base," commonly called the "Blue Book," is a user's
guide for preparing and submitting geodetic data for
incorporation into NGS' data base.  Survey data that are entered
into NGS' data base become part of the National Spatial Reference
System (NSRS), formerly the National Geodetic Reference System. 
The guide comprises three volumes.  Volume I covers classical
horizontal geodetic and Global Positioning System (GPS) data,
volume II covers vertical geodetic data, and volume III covers
gravity data.  Beginning with this edition, the three formerly
separate volumes are distributed as a set, since a great deal of
information is common to each volume.  Because some of the
chapters and annexes are identical in all three volumes, the
original numbering design has been retained.  

The formats and specifications are consistent with the aims of
the Executive Office of the President, Office of Management and
Budget's (OMB) Circular A-16, as revised in 1990.  A major goal
of the circular, which is titled "Coordination of Surveying,
Mapping, and Related Spatial Data Activities," is to develop a
national spatial data infrastructure with the involvement of
Federal, state, and local governments, and the private sector. 
This multilevel national information resource, united by
standards and criteria established by the Federal Geodetic
Control Subcommittee (FGCS) of the Federal Geographic Data
Committee (FGDC), will enable the sharing and efficient transfer
of geospatial data between producers and users.

Survey data that are submitted to NGS for incorporation into NSRS
should be properly formatted and supply minimum accuracies of:
     First-order horizontal accuracy standards for GPS and
     conventional horizontal surveys;
     Second-order, class II vertical accuracy standards for
     conventional leveling;
     Third-order gravity standards for gravity surveys. 

Effective July 1, 1995, survey project data must meet the above
minimum accuracy standards to be accepted for inclusion into the
NGS data base.  Surveys that are of lower order than given above
will be accepted only in exceptional cases approved by the Chief,
NGS. 

In addition, these data standards and accuracies should be
verified and the survey data contributed for inclusion into the
NGS data base should be processed and adjusted by the provider,
using currently available NGS software, before submitting the
survey project to NGS.  

At this time, NGS provides review, archiving, and distribution
functions free of charge for survey data submitted in the proper
format.  These surveys must contain connections to NSRS in
accordance with FGCS Standards and Specifications and they must
contribute to the public good. 
The production of the Blue Book entailed significant
contributions from a number of NGS employees.  Notable among
these are D. Sherrill Snellgrove for his revision of  Volume I,
originally prepared by then-Commander Ludvik Pfeifer, NOAA
(Ret.); Nancy L. Morrison and Commander Pfeifer, for their
contributions to preparing Volume II; and then-Lieutenant Warren
T. Dewhurst, NOAA, for his preparation of Volume III.

This publication and most of the documents referenced herein may
be obtained from:

     NOAA, National Geodetic Survey, N/CG174
     1315 East-West Highway, Station 9202
     Silver Spring, MD 20910-3282
     Telephone: (301) 713-3242; Fax: (301) 713-4172 
     Monday through Friday, 7:00 a.m. - 4:30 p.m. Eastern Time.



  
CONTENTS - VOLUME I

                                                                   
   

Chapter 1 - HORIZONTAL CONTROL (HZTL) DATA

Chapter 2 - HORIZONTAL OBSERVATION (HZTL OBS) DATA

Chapter 3 - GEODETIC CONTROL DESCRIPTIVE (GEOD DESC) DATA


ANNEX A - NGS STATE AND COUNTRY CODES

ANNEX B - STATE PLANE COORDINATES (SPC) ZONE CODES

ANNEX C - CONTRIBUTORS OF GEODETIC CONTROL DATA

ANNEX D - GUIDELINES FOR GEODETIC CONTROL POINT DESIGNATIONS

ANNEX E - STATION ORDER-AND-TYPE (OT) CODES

ANNEX F - NGS SURVEY EQUIPMENT CODES

ANNEX G - ELLIPSOID HEIGHT ORDER-AND-CLASS (OC) CODES

ANNEX H - STANDARD TIME ZONES

ANNEX I - SUMMARY OF CODES USED IN GEODETIC SURVEY POINT
DESCRIPTIONS

ANNEX K - PROJECT REPORT INSTRUCTIONS

ANNEX L - GUIDELINES FOR SUBMITTING GPS RELATIVE POSITIONING DATA

ANNEX N - GLOBAL POSITIONING SYSTEM DATA TRANSFER FORMAT
                                                                   
           



















                                iii
CONTENTS - VOLUME I                                           
                                                            PAGE


Chapter 1 - HORIZONTAL CONTROL (HZTL) DATA . . . . . . . . . . . .
. . 1-1

    INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . .
. . 1-1

    JOB CODE AND SURVEY POINT NUMBERING  . . . . . . . . . . . . .
. . 1-1

    MEDIA FOR SUBMITTING DATA  . . . . . . . . . . . . . . . . . .
. . 1-3

        FIGURE 1-1 - Station serial numbers assigned
                       to control points . . . . . . . . . . . . .
. . . 1-4
        FIGURE 1-2 - Station serial numbers assigned               
                                  to control points and
                     to peripheral points  . . . . . . . . . . . .
. . 1-5

    CODING, KEYING, AND DATA VERIFICATION  . . . . . . . . . . . .
. . 1-6

    SPECIAL CHARACTERS . . . . . . . . . . . . . . . . . . . . . .
. . 1-7

    SEQUENTIAL RECORD NUMBERING  . . . . . . . . . . . . . . . . .
. . 1-7


Chapter 2 - HORIZONTAL OBSERVATION (HZTL OBS) DATA . . . . . . . .
. . 2-1

    INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-1
    
    HZTL OBS DATA SET RECORDS  . . . . . . . . . . . . . . . . . .
. . 2-1
        TABLE 2-1 - Horizontal Observation Data Set Records  . . .
. . 2-2

    STRUCTURE OF THE HZTL OBS DATA SET . . . . . . . . . . . . . .
. . 2-3
        TABLE 2-2 - HZTL OBS Structure . . . . . . . . . . . . . .
. . 2-3

    PROJECT DATA RECORDS . . . . . . . . . . . . . . . . . . . . .
. . 2-5
        Project Title  . . . . . . . . . . . . . . . . . . . . . .
. . 2-5
        Survey Method. . . . . . . . . . . . . . . . . . . . . . .
. . 2-6
        Order and Class of Survey  . . . . . . . . . . . . . . . .
. . 2-6

    DATE AND TIME  . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-7
        Date . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-7
        Time . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-7
        Time Zone  . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-7
        TABLE 2-3 - U.S. Navy Time Zone Designations . . . . . . .
. . 2-8

    OBSERVATION DATA RECORDS . . . . . . . . . . . . . . . . . . .
. . 2-8
        Standpoint and Forepoint . . . . . . . . . . . . . . . . .
. . 2-9
        Station Serial Number  . . . . . . . . . . . . . . . . . .
. . 2-9
        Weather Code . . . . . . . . . . . . . . . . . . . . . . .
. . 2-10
        TABLE 2-4 - Weather Code . . . . . . . . . . . . . . . . .
. . 2-10
        Job-Specific Instrument Number . . . . . . . . . . . . . .
. . 2-10
        Height of Instrument and Height of Target  . . . . . . . .
. . 2-11
        Visibility Code  . . . . . . . . . . . . . . . . . . . . .
. . 2-11
                                                                   
  


                                iv
CONTENTS - VOLUME I                                           
                                                            PAGE

       
    ASSIGNMENT OF STATION SERIAL NUMBERS . . . . . . . . . . . . .
. . 2-12
        Control Points . . . . . . . . . . . . . . . . . . . . . .
. . 2-12
        Peripheral Points  . . . . . . . . . . . . . . . . . . . .
. . 2-13

    TREATMENT OF ECCENTRIC OBSERVATIONS  . . . . . . . . . . . . .
. . 2-14
        Method A . . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-14
        Method B . . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-14

    ACCURACY OF THE OBSERVATIONS . . . . . . . . . . . . . . . . .
. . 2-15
        Number of Replications . . . . . . . . . . . . . . . . . .
. . 2-16
        Rejection Limit  . . . . . . . . . . . . . . . . . . . . .
. . 2-16
        Internal Consistency Sigma . . . . . . . . . . . . . . . .
. . 2-17
        External Consistency Sigma . . . . . . . . . . . . . . . .
. . 2-17

    HORIZONTAL DIRECTION DATA RECORDS  . . . . . . . . . . . . . .
. . 2-17
        Set Number . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-18
       Number of Objects Sighted in This Set  . . . . . . . . . .
   . . 2-18
        Date and Time  . . . . . . . . . . . . . . . . . . . . . .
. . 2-18

   GLOBAL POSITIONING SYSTEM DATA RECORDS . . . . . . . . . . . .
   . . 2-18
       Job-Specific Data Media Identifier . . . . . . . . . . . . .
       . 2-19

    HORIZONTAL ANGLE DATA RECORDS  . . . . . . . . . . . . . . . .
. . 2-19
        Set Number . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-20
        Number of Angles Observed in This Set  . . . . . . . . . .
. . 2-20
        Date and Time  . . . . . . . . . . . . . . . . . . . . . .
. . 2-20

    VERTICAL ANGLE/ZENITH DISTANCE DATA RECORDS  . . . . . . . . .
. . 2-21
        Set Number . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-22
        Number of VAs or ZDs Observed in This Set  . . . . . . . .
. . 2-22
        Date and Time  . . . . . . . . . . . . . . . . . . . . . .
. . 2-22
        Angle Code . . . . . . . . . . . . . . . . . . . . . . . .
. . 2-22

    LEVEL DATA RECORDS . . . . . . . . . . . . . . . . . . . . . .
. . 2-23
        Number of Replications . . . . . . . . . . . . . . . . . .
. . 2-23 
        Date and Time  . . . . . . . . . . . . . . . . . . . . . .
. . 2-24       
    DISTANCE DATA RECORDS  . . . . . . . . . . . . . . . . . . . .
. . 2-24
        Date and Time  . . . . . . . . . . . . . . . . . . . . . .
. . 2-25
        Distance Code  . . . . . . . . . . . . . . . . . . . . . .
. . 2-26
       
    AZIMUTH DATA RECORDS . . . . . . . . . . . . . . . . . . . . .
. . 2-26
        Date and Time  . . . . . . . . . . . . . . . . . . . . . .
. . 2-27
        Origin of Azimuth  . . . . . . . . . . . . . . . . . . . .
. . 2-27

    SURVEY EQUIPMENT DATA RECORDS  . . . . . . . . . . . . . . . .
. . 2-28
        NGS Survey Equipment Code  . . . . . . . . . . . . . . . .
. . 2-28
        Resolution of the Instrument and Units . . . . . . . . . .
. . 2-28





                                 v
CONTENTS - VOLUME I                                           
                                                            PAGE


   SURVEY POINT DATA RECORDS  . . . . . . . . . . . . . . . . . .
   . . 2-29
       Station Name . . . . . . . . . . . . . . . . . . . . . . . .
       . 2-30
        Name or Designation of RM or AZ MK . . . . . . . . . . . .
. . 2-32
       Name or Designation of Bench Mark  . . . . . . . . . . . . .
       . 2-33
       Geodetic Position  . . . . . . . . . . . . . . . . . . . . .
       . 2-34
       Elevation and Elevation Code . . . . . . . . . . . . . . . .
       . 2-34
       Station Order and Type . . . . . . . . . . . . . . . . . . .
       . 2-35
       TABLE 2-5 - Allowable Order Codes  . . . . . . . . . . . . .
       . 2-37
       TABLE 2-6 - Allowable Type Codes . . . . . . . . . . . . . .
       . 2-38
       Geoid Height . . . . . . . . . . . . . . . . . . . . . . . .
       . 2-38
       Deflection of Vertical . . . . . . . . . . . . . . . . . . .
       . 2-39

   FIXED CONTROL DATA RECORDS . . . . . . . . . . . . . . . . . .
   . . 2-40

   RECORD FORMATS . . . . . . . . . . . . . . . . . . . . . . . .
   . . 2-41
       Required Data  . . . . . . . . . . . . . . . . . . . . . . .
       . 2-41  
       Data Set Identification Record . . . . . . . . . . . . . . .
       . 2-42 
        Project Data (*10*-Series) Records . . . . . . . . . . . .
. . 2-43  
        Horizontal Direction Data (*20*-Series) Records  . . . . .
. . 2-46
        Global Positioning System Data Records . . . . . . . . . .
. . 2-50     
        Horizontal Angle Data (*30*-Series) Records  . . . . . . .
. . 2-54  
        Vert Angle/Level Data (*40*-Series) Records  . . . . . . .
. . 2-59
        Distance Data (*50*-Series) Records  . . . . . . . . . . .
. . 2-64   
        Azimuth Data (*60*-Series) Records   . . . . . . . . . . .
. . 2-73
        Survey Equipment Data (*70*) Record  . . . . . . . . . . .
. . 2-76  
        Survey Point Data (*80*-Series) Records  . . . . . . . . .
. . 2-77   
        Fixed Control Data (*90*) Record . . . . . . . . . . . . .
. . 2-86  
        Data Set Termination Record  . . . . . . . . . . . . . . .
. . 2-87
  
    FORMAT DIAGRAMS. . . . . . . . . . . . . . . . . . . . . . . .
. . 2-88

      
Chapter 3 - GEODETIC CONTROL DESCRIPTIVE (GEOD DESC) DATA  . . . .
. . 3-1   

    INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . .
. . 3-1   

    WRITING DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . .
. . 3-1

    STRUCTURE OF THE GEOD DESC DATA SET  . . . . . . . . . . . . .
. . 3-2
    RECORD DEFINITIONS . . . . . . . . . . . . . . . . . . . . . .
. . 3-2
    TITLE AND COMMENT RECORDS  . . . . . . . . . . . . . . . . . .
. . 3-2

    CODE *00* - *04* (PROJECT AND TITLE INFORMATION RECORDS) . . .
. . 3-2

    CODE *05* (COMMENT RECORD) . . . . . . . . . . . . . . . . . .
. . 3-3

    DESCRIPTION RECORDS  . . . . . . . . . . . . . . . . . . . . .
. . 3-3






                                vi
CONTENTS - VOLUME I                                           
                                                            PAGE

   CODE *10* (STATION LOCATION RECORD)  . . . . . . . . . . . . .
   . . 3-3
        Station Serial Number  . . . . . . . . . . . . . . . . . .
. . 3-3
        DR Code  . . . . . . . . . . . . . . . . . . . . . . . . .
. . 3-3
        Recovery Type Code . . . . . . . . . . . . . . . . . . . .
. . 3-3
        Approximate Position   . . . . . . . . . . . . . . . . . .
. . 3-4
        Approximate Height . . . . . . . . . . . . . . . . . . . .
. . 3-4
        Quad Identifier  . . . . . . . . . . . . . . . . . . . . .
. . 3-4
        FIGURE 3-1 (Quad Identifier Graphic Format). . . . . . . .
. . 3-5
        State/Country Code . . . . . . . . . . . . . . . . . . . .
. . 3-6
        County . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 3-6
        Special Application Code . . . . . . . . . . . . . . . . .
. . 3-6
        Permanent Identifier . . . . . . . . . . . . . . . . . . .
. . 3-6

    CODE *13* (STATION IDENTIFICATION RECORD)  . . . . . . . . . .
. . 3-6
        Designation  . . . . . . . . . . . . . . . . . . . . . . .
. . 3-6
        Underground Marker Type/Magnetic Property Code . . . . . .
. . 3-7
        Setting Code (Underground Marker)  . . . . . . . . . . . .
. . 3-7
        Transportation Code  . . . . . . . . . . . . . . . . . . .
. . 3-7
        Backpack-Time  . . . . . . . . . . . . . . . . . . . . . .
. . 3-7

    CODE *15* (ALIAS RECORD) . . . . . . . . . . . . . . . . . . .
. . 3-7

    CODE *20* (MONUMENTED/RECOVERED RECORD). . . . . . . . . . . .
. . 3-8
       Monumenting Agency Group Code  . . . . . . . . . . . . . . .
       . 3-8
       Monumenting Agency Symbol  . . . . . . . . . . . . . . . . .
       . 3-8
       Year Monumented  . . . . . . . . . . . . . . . . . . . . . .
       . 3-8
       Chief of Party . . . . . . . . . . . . . . . . . . . . . . .
       . 3-8
       Recovering Agency Group Code . . . . . . . . . . . . . . . .
       . 3-8
       Recovering Agency Symbol . . . . . . . . . . . . . . . . . .
       . 3-8
       Date Recovered   . . . . . . . . . . . . . . . . . . . . . .
       . 3-8
       Chief of Party   . . . . . . . . . . . . . . . . . . . . . .
       . 3-9
       Recovery Condition Code  . . . . . . . . . . . . . . . . . .
       . 3-9

    CODE *26* (SETTING RECORD) . . . . . . . . . . . . . . . . . .
. . 3-9
       Setting Code . . . . . . . . . . . . . . . . . . . . . . . .
       . 3-9
       Surface Marker Type    . . . . . . . . . . . . . . . . . . .
       . 3-9
       Magnetic Code (Surface Marker) . . . . . . . . . . . . . . .
       . 3-10
       Vertical Stability Override Code . . . . . . . . . . . . . .
       . 3-10
       Marker Inscription . . . . . . . . . . . . . . . . . . . . .
       . 3-10

    CODE *28* (STAMPING RECORD)  . . . . . . . . . . . . . . . . .
. . 3-10

    CODE *29* (ROD/PIPE RECORD)  . . . . . . . . . . . . . . . . .
. . 3-11

    CODE *30* (TEXT RECORDS)   . . . . . . . . . . . . . . . . . .
. . 3-11

   SAMPLE DESCRIPTION DATA SETS . . . . . . . . . . . . . . . . .
   . . 3-12

    FORMAT DIAGRAMS  . . . . . . . . . . . . . . . . . . . . . . .
. . 3-17           
    



                                vii
CONTENTS - VOLUME I                                           
                                                            PAGE


ANNEX A - NGS STATE AND COUNTRY CODES  . . . . . . . . . . . . . .
. . A-1

ANNEX B - STATE PLANE COORDINATES (SPC) ZONE CODES . . . . . . . .
. . B-1

ANNEX C - CONTRIBUTORS OF GEODETIC CONTROL DATA  . . . . . . . . .
. . C-1

ANNEX D - GUIDELINES FOR GEODETIC CONTROL POINT DESIGNATIONS . . .
. . D-1

ANNEX E - STATION ORDER-AND-TYPE (OT) CODES  . . . . . . . . . . .
. . E-1

ANNEX F - NGS SURVEY EQUIPMENT CODES . . . . . . . . . . . . . . .
. . F-1

ANNEX G - ELLIPSOID HEIGHT ORDER-AND-CLASS (OC) CODES  . . . . . .
. . G-1

ANNEX H - STANDARD TIME ZONES  . . . . . . . . . . . . . . . . . .
. . H-1

ANNEX I - SUMMARY OF CODES USED IN GEODETIC SURVEY POINT
DESCRIPTIONS  I-1

ANNEX K - PROJECT REPORT INSTRUCTIONS  . . . . . . . . . . . . . .
. . K-1

ANNEX L - GUIDELINES FOR SUBMITTING GPS RELATIVE POSITIONING DATA 
. . L-1

ANNEX N - GLOBAL POSITIONING SYSTEM DATA TRANSFER FORMAT . . . . .
. . N-1






























                               viii
                             Chapter 1

                  HORIZONTAL CONTROL (HZTL) DATA

INTRODUCTION

For coding and processing purposes, data associated with geodetic
horizontal control (HZTL data) have been divided into two groups. 
These two groups are 
(1) field observations (OBS data) and (2) descriptions and
recovery notes (DESC data).  Detailed instructions and formats for
coding and keying horizontal control OBS and DESC data sets are
contained in Chapters 2 and 3.  The treatment of all data normally
generated in the conduct of a classical horizontal control survey
(triangulation, trilateration, and/or traverse) is described.

Although both types of data are normally generated in a horizontal
control survey, OBS and DESC data must be submitted to NGS in
separate data sets.  These will be inserted in the National
Geodetic Survey Data Base.                                         
    
The foregoing implies that every horizontal control survey project
(or several small projects submitted as one "job" - see below)
will be received at NGS as two distinct data sets HZTL OBS and
GEOD DESC data sets.  The two data sets created for each
horizontal control job must be submitted at the same time. 

JOB CODE AND SURVEY POINT NUMBERING                                
      

The basic unit or group of data is given the name "job."  A
horizontal control job can contain the data for a maximum of 9999
survey points - see the definition of "survey point" below.  If
the number of survey points in a horizontal control survey project
exceeds this limit, the data must be divided and submitted in
multiple jobs.  A job will normally contain the data collected for
one project (i.e., one unit of field work); however, several small
projects can be included in one job, even though they may have no
points in common.  The preferred determining factor in selecting
several small horizontal control survey projects for inclusion in
any one job is geographic proximity.

A two-character alphanumeric job code must be assigned to each
horizontal control job submitted by an organization.  The job
code, along with the data set type, the name of the submitting
agency, and the data set creation date will serve to uniquely
identify each data set received by NGS.  The first character of
the two-character job code must always be a letter; the second
character may be either a letter or a number (1 through 9).  The
preferred method of assigning job codes is to begin with Al and
end with ZZ, i.e., Al, A2, ..., A9, Bl, ..., Zl, ..., Z9, AA, AB,
..., ZZ.  This allows for a total of 910 uniquely-identified
horizontal control jobs to be submitted by any one organization. 
Should this sequence be exhausted, the job codes may then be
assigned again from the beginning - Al, A2, etc.










                                1-1
A horizontal control point is defined as any survey point whose
position has  been previously determined and is in the NGS Data
Base, whose position is to be determined in an adjustment of the
submitted HZTL OBS data, or whose (adjusted) position is available
from another source.  A survey point is defined as any point which
has one or more directions, angles (horizontal or vertical),
distances or vectors measured to it or from it.  A survey point
may be a monumented (or otherwise permanently marked) control
point, a reference mark or azimuth mark, a temporary point (not
permanently marked and therefore non- recoverable) such as an
auxiliary point, or an unmonumented recoverable landmark (usually
an intersection station) such as a flagpole or church spire.  An
eccentric instrument setup and eccentric target (or reflector)
also qualify as survey points under this definition.

Each survey point in a horizontal control job must be assigned a
unique four-digit station serial number within the range 0001
through 9999.  A unique station serial number not only identifies
the various observations within the HZTL OBS data set but is the
project specific link between data in the HZTL OBS data set and
data in the GEOD DESC data set.

Normally there are many survey points in a horizontal control job
which are not intended as control points.  These points are, by
their nature, peripheral to a control point.  Examples of
peripheral points are unoccupied reference and azimuth marks. 
Eccentric instrument setups and eccentric targets (or reflectors)
are treated as peripheral points if the respective eccentric
observations are to be reduced to center.  This is usually the
case when the eccentric point is not permanently marked.  But, if
an eccentric point is offset more than 10 meters from the control
point to which it belongs (even though it may be unmarked), or if
the eccentric point is permanently marked (e.g., a reference mark
is occupied), then the respective eccentric observations should
not be reduced to center, and the eccentric point should be
treated as another control point.

When an eccentric instrument setup is utilized in a field project,
whose offset distance from the respective control point does not
exceed 10 meters, the respective eccentric observations should be
reduced to center by the submitting organization and coded in the
HZTL OBS deck as if the control station had been occupied.  If,
for any reason, this is not desired, the eccentric point in
question must be carried as a control point and must be assigned a
four-digit station serial number of its own. 

An unoccupied reference or azimuth mark has one or more
directions, angles, and/or distances measured to it but not from
it.  A reference mark or azimuth mark which is occupied as a part
of the survey scheme (e.g., as an eccentric occupation of the
respective control point) should always be treated as a distinct
control point.  However, a reference or azimuth mark with
directions, angles, and/or distances measured from it (as well as
to it) for the purpose of verifying and/or supplementing the
observations which tie together the control point and its
peripheral points may remain a peripheral point.                   
   
The observations (directions, angles, and/or distances) which link
the peripheral points with the respective control points must
appear in the
appropriate subset of the HZTL OBS data set (see Chapter 2).




                                1-2                            
Figures 1-1 and 1-2 illustrate an assignment of station serial
numbers to control points and to their peripheral points
(reference marks, azimuth marks, and/or eccentric points).  The
numbering system provides unique identifiers for all the survey
points.  An AZ MK or RM which is being treated as a control point
must not also be identified as a peripheral point in the OBS data
set.  The same station serial number must be consistently used
throughout the OBS or DESC data set of a horizontal control job.

As stated in the INTRODUCTION, a horizontal control job consists
of two separate data sets - the HZTL OBS data set and the GEOD
DESC data set.  The HZTL OBS data set may contain a greater number
of points than the corresponding GEOD DESC data set.  This might
occur when there is no descriptive data for the peripheral points
and for unmarked (auxiliary) points.  Station descriptions or
recovery notes are required only for recoverable survey points. 
Apart from the peripheral points, there may be a number of
nonrecoverable control points (either originally unmarked or
confirmed lost) which must be carried along in the OBS data set
for network integrity purposes.  There may also be recovery notes
for stations not used or found destroyed in a survey. 
Observations for such stations would not be in the OBS data set. 
In isolated instances, there may be recoverable control points for
which no descriptive data are available.
In these instances the submitting organization should write a
description for each recoverable control point and include it in
the GEOD DESC data set.
   
When recording data on magnetic tape or floppy disks (see MEDIA
FOR SUBMITTING DATA), the two data sets of a horizontal control
job must be submitted in  separate files.  These files may be on
the same disk/reel of tape or on different disks/reels.  In any
case, the first record of every data set (see Chapters 2 and 3)
must contain information positively identifying the data and
project: the job code, the data set type, the name of the
submitting agency, and the data set creation date.
                                                         
MEDIA FOR SUBMITTING DATA

Although, in principle, any computer-readable, general-purpose
data-recording medium can be handled, the two media currently
acceptable to NGS are the 5 1/4 inch and 3 1/2 inch floppy disk
and the standard 1/2 inch magnetic tape.  Magnetic tape should be
used only as the medium for submitting large volumes of data. 
Floppy disks are preferred when submitting a single job or jobs
which contain small to medium amounts of data.

When data are submitted on floppy disks, the files must be created
using an
MS DOS operating system and be in ASCII character format.          
                                                              
The following information must be provided for each floppy disk
submitted:

       1.  Complete name and address of the submitting agency.

       2.  Number of files and the name of each file on the disk.   
                                 
       3.  Method of keying data and machine used (e.g., MTEN on
       the IBM PC).
                                                                   
                 4.  Disk format (360 k, 750 k, 1.2 m, or 1.4 m are
                 acceptable).

       5.  Name and telephone number of the person to be contacted
       in case
           of difficulty with the data.

                                1-3
This information should be furnished in a letter of transmittal. 
A copy should be packed with the data set.

When the data are submitted as files of formatted records on
magnetic tape, the following information is expected to be given
for each reel of tape:

       1.  Name and address of the submitting agency.

       2.  Reel number or identification symbol assigned
           by the submitting agency.

       3.  Number of files and contents of each file
            by job code and data type (e.g. Al HZTL OBS,
            XX GEOD DESC, etc.).

       4.  Computer system on which the tape was created
            (e.g., IBM 360/XXX, CDC 6600, etc.)

        5.  Internal label information (e.g. non-labeled,
            standard IBM label, etc.).
                                     
       6.  Number of tracks (7 or 9) and parity (even or odd).

       7.  Recording density (556, 800 or 1600 BPI).

       8.  Record length (LRECL) and block size (BLKSIZE).

       9.  Character representation code (BCD, EBCDIC, etc.)        
                       and keytape equipment designation, if
applicable.

      10.  Name and phone number of person to be contacted
            in case of difficulty with the data.

This information should be furnished in a letter of transmittal. 
A copy should be packed with the data set.

A letter describing and itemizing the data transmitted should
always be prepared for each data shipment.  One copy should be
enclosed with the data shipment, one sent by separate mail to NGS,
and another copy retained by the sender.  See ANNEX K  for current
mailing instructions.  In every case, the submitting organization
should retain a backup copy of all the data shipped until NGS
acknowledges receipt of the data.                            

CODING, KEYING, AND DATA VERIFICATION

All data submitted to NGS for insertion into the National Geodetic
Survey Data Base must be coded and keyed in strict conformity with
the formats and specifications contained in this publication.  In
addition, the keying of all data must be verified.  







                                1-6
Detailed formats and specifications for the coding and keying of
horizontal control jobs are contained in Chapter 2 (HZTL OBS data)
and in Chapter 3 (GEOD DESC data).  The formats were designed to
allow the keying and verification of the data to be accomplished
on standard computer equipment, hence the
80-character record was adopted as the standard for all
applications.

When coding and keying the data entries, carefully insure that
alphabetic
characters (letters) will be keyed using the alphabetic keys, and
that numeric characters (numbers) will be keyed using the numeric
keys.  In particular, miscoding and miskeying the following
characters must be avoided:

       0 - number "zero"   1 - number "one"    2 - number "two"
       0 - letter "0"      L - letter "L"      Z - letter "Z"

SPECIAL CHARACTERS

In addition to the alphabetic characters (letters A through Z) and
the numeric characters (numbers 0 through 9), only the following
special characters are allowed:

       (*) asterisk        (+) plus sign
       ( ) blank or space     (-) minus sign or hyphen
       (,) comma           (=) equal sign
       (.) period or          (/) slash or solidus
          decimal point       (() left parenthesis
       ($) dollar sign        ()) right parenthesis

SEQUENTIAL RECORD NUMBERING

The first six characters of every record are reserved for a record
sequence
number.  The purpose of numbering records sequentially is to
insure that the proper sequence of individual records in a data
set can be verified and, if necessary, restored.  The sequencing
numbers must be assigned in ascending order, starting with the
first record (the Data Set Identification Record) and ending with
the last record (the Data Set Termination Record).

The preferred assignment of sequence numbers starts with 000010 on
the first record in the data set (the Data Set Identification
Record) and increments by 10 on each successive record.  This
numbering system allows up to nine records to be inserted between
any two originally numbered records without the necessity of
renumbering any records in the data set.  Even when a large block
of omitted records must be inserted, only a few of the existing
records will have to be renumbered.  To allow for the detection of
missing records, all insertions and/or deletions which deviate
from the basic 000010, 000020, 000030, etc. "increment-by-ten"
record sequence must be accounted for in the letter of
transmittal.                   

Discounting any after-the-fact insertions, the above-described
sequential   numbering system will permit a maximum of 99,999
uniquely-numbered records
in any one data set.  Should there ever be a need for a greater
number of  records in a data set, retain only the last six digits
of the higher
sequence numbers, i.e., ... 999980, 999990, 000000, 000010, etc.




                                1-7



















                        INTENTIONALLY BLANK




































                                1-8
                             Chapter 2


              HORIZONTAL OBSERVATION (HZTL OBS) DATA


INTRODUCTION

The purpose of this chapter is to provide detailed specifications
and instructions for the coding and keying of an observation data
set for a horizontal control job.  As explained in Chapter 1, a
horizontal control job consists of two distinct data sets which
must be submitted together.  The companion data set to the
horizontal observation (HZTL OBS) data set discussed in this
chapter is the data set which contains descriptions and/or
recovery notes for the control points in the horizontal control
job.  The descriptive (GEOD DESC) data set is discussed in Chapter
3.


HZTL OBS DATA SET RECORDS

The data which constitute an HZTL OBS data set are organized into
ten categories, which are as follows:

                     Project Data
                     Horizontal Direction Data
                     Global Positioning System Data
                     Horizontal Angle Data
                     Vertical Angle/Zenith Distance/Level Data
                     Distance Data
                     Azimuth Data
                     Survey Equipment Data
                     Control Point Data
                     Fixed Control Data

Within these categories, the data have been grouped into one or
more logical units called "records."  A record is a string of
characters containing data coded according to a specific format. 
Every record in an HZTL OBS data set consists of 80 characters or
"columns" (standard punched card image).  Within each record, the
80 columns are divided into fixed-length "character fields,"  each
field reserved for a specific data item.  Accordingly, for every
desired data item, a field of appropriate length exists into which
the data item is  entered.  The set of rules by which the specific
data items are converted into strings of alphanumeric characters
is known as the "format" of that record.

The types of records which may appear in an HZTL OBS data set are
listed in Table 2-1 on the following page.  Each type of record
has been given a name.  A  block diagram portraying the data
fields and a brief description of each data field in that record
can be found in the FORMAT DIAGRAMS.








                                2-1
                             TABLE 2-1

              HORIZONTAL OBSERVATION DATA SET RECORDS
Ŀ
      [FIRST RECORD]                                                
 *aa* - Data Set Identification Record                              
 *10* - Project Title Record                                        
 *11* - Project Title Continuation Record                           
 *12* - Project Information Record                                  
 *13* - Geodetic Datum and Ellipsoid Record                         
 *20* - Horizontal Direction Set Record                             
 *21* - Horizontal Direction Comment Record (Optional)              
 *22* - Horizontal Direction Record                                 
 *25* - GPS Occupation Header Record                                
 *26* - GPS Occupation Comment Record (optional)                    
 *27* - GPS Occupation Measurement Record                           
 *28* - GPS Clock Synchronization Record                            
 *29* - GPS Clock Synchronization Comment Record (optional)         
 *30* - Horizontal Angle Set Record                                 
 *31* - Horizontal Angle Comment Record (Optional)                  
 *32* - Horizontal Angle Record                                     
 *40* - Vertical Angle Set Record                                   
 *41* - Vertical Angle Comment Record (Optional)                    
 *42* - Vertical Angle Record                                       
 *45* - Observed Difference of Elevation Record                     
 *46* - Observed Difference of Elevation Comment Record (optional)  
 *47* - Observed Difference of Elevation Continuation Record        
 *50* - Taped Distance Record                                       
 *51* - Unreduced Distance Record                                   
 *52* - Reduced Distance Record                                     
 *53* - Unreduced Long Line Record                                  
 *54* - Reduced Long Line Record                                    
 *55* - Distance Comment Record (Optional)                          
 *60* - Laplace / Astronomic Azimuth Record                         
 *61* - Geodetic Azimuth Record                                     
 *70* - Instrument Record                                           
 *80* - Control Point Record                                        
 *81* - Control Point Record (UTM/SPC)                              
 *82* - Reference or Azimuth Mark Record                            
 *83* - Bench Mark Record [discontinued-Use *86* record instead]    
 *84* - Geoid Height Record (Optional) [discontinued-Use *86*]      
 *85* - Deflection Record (Optional)                                
 *86* - Orthometric Height, Geoid Height, Ellipsoid Height Record   
 *90* - Fixed Control Record                                        
        [LAST RECORD]                                               
 *aa* - Data Set Termination Record                                 

______________________________________________________________________

Note:  The symbol "aa" denotes the two-character job code assigned
          by the submitting organization - see Chapter 1.
                                                                   
 
                                                                   
 



                                2-2
Except for the first and last records of the data set, the second
character field of each record (columns 7-10) contains a two-digit
numerical data code, preceded and followed by an asterisk, which
specifies the format type for that record (*10*,*11*,...,*90* -
see Table 2-1).  In the first and last records of the data set
(the Data Set Identification Record and the Data Set Termination
Record) the second character field (columns 7-10) contains the
two-character alphanumeric job code assigned by the submitting
organization (*A1*,*A2*,....,   *ZZ* - see Chapter 1).  The first
character field of every record (columns 1-6) is reserved for the
respective record sequence number - see Chapter 1.  The remaining
portion of each record (columns 11-80) contains character fields
which are unique to each type of record. 


STRUCTURE OF THE HZTL OBS DATA SET

The first record of an HZTL OBS data set must be the Data Set
Identification Record.  It contains the required information to
identify the data set and to correlate it with its companion GEOD
DESC data set - job code, data type (HZTL OBS), name of submitting
organization, and date the data set was created.  The last record
of the data set must be the Data Set Termination Record.  It is
the only other record in the data set containing the job code that
appears in the same field (columns 7-10) on the Data Set
Identification Record.
        
The HZTL OBS data set is bracketed by these two delimiting
records.  The data in between may pertain to one or more units of
field work.  The field observation data for several horizontal
control survey projects may be submitted in one HZTL OBS data set
under the same job code, provided that the total number of control
points does not exceed 9999 (see Chapter 1).  When two or more
projects are included in one job, each project must be grouped to
form a complete unit.  Each project must begin with a *10* record,
contain any number of the other types of records in proper
sequence, and terminate with one or more *90* records.
    


                         TABLE 2-2 - HZTL OBS STRUCTURE   
                           Data Set Identification Record  
                        *10* record                    
                        ::::           First Project   
                           *90* record                    
                        *10* record                    
                        ::::           Second Project  
                        *90* record                    
                                                       
                        ::::           ::::            
                                                       
                        *10* record                    
                        ::::           Last Project    
                        *90* record                    
                        Data Set Termination Record     
                     ͼ
  





                                2-3
A horizontal control survey project is defined as a unit of field
work containing a number of survey points (control points and
peripheral
points - see Chapter 1) which are connected by observations -
horizontal   
directions, horizontal angles, vertical angles, distance
measurements, and/or Global Positioning System (GPS) phase 
measurements.  When coded as a part of an HZTL OBS data set, a
project is a block of records comprising record groups arranged in
the following order:

    Project Data (*10*-Series) Records:
    
    *10*,*11*,*12*,*13* records                             
 
    Horizontal Direction Data (*20*-Series) Records:          
    
    *20*,*21*,*22*,...,*22* for first set of horizontal directions
    *20*,*21*,*22*,...,*22* for second set of horizontal
directions
    ::::
    *20*,*21*,*22*,...,*22* for last set of horizontal directions

    Global Positioning Systems Data (*20*-Series) Records:

    *25*,*26*,*27*,*27*     for first set of GPS data
    *25*,*26*,*27*,*27*     for second set of GPS data
    ::::
    *25*,*26*,*27*,*27*     for last set of GPS data
    *28*,*29*               for each clock synchronization

(These records may be in any order within the GPS data series
records)

    Horizontal Angle Data (*30*-Series) Records:              

    *30*,*31*,*32*,...,*32* for first set of horizontal angles
    *30*,*31*,*32*,...,*32* for second set of horizontal angles   
    ::::
    *30*,*31*,*32*,...,*32* for last set of horizontal angles

    Vertical Angle/Zenith Distance/Level Data (*40*-
Series) Records:    

    *40*,*41*,*42*,...,*42* for first set of vertical angles
    *40*,*41*,*42*,...,*42* for second set of vertical angles    
    ::::
    *40*,*41*,*42*,...,*42* for last set of vertical angles

    *45*,*46*,*47*          for first elevation difference
    *45*,*46*,*47*          for second elevation difference
    *45*,*46*,*47*          for last elevation difference

    Distance Data (*50*-Series) Records:                  

    *50*,*55* for each taped distance
    *51*,*55* for each unreduced line-of-sight distance       
    *52*,*55* for each reduced line-of-sight distance
    *53*,*55* for each unreduced long-line distance
    *54*,*55* for each reduced long-line distance              


                                2-4
    Azimuth Data (*60*-Series) Records:

    *60* for each observed astronomic/Laplace azimuth in the
project    
    *61* for each geodetic azimuth used in the project

    Survey Equipment Data (*70*) Records:
    
    *70* for each item of survey equipment used in the project     
                                                 
    Survey Point Data (*80*-Series) Records:
           
    *80* or *81* for first control point
    *82* for each peripheral RM or AZ MK at first control point
    *85*,*86*, as applicable, for first control point
    *80* or *81* (possibly *82*) for second control point
    *82* for each peripheral RM or AZ MK at second control point
    *85*,*86*, as applicable, for second control point 
    ::::
    *80* or *81* (possibly *82*) for last control point
    *82* for each peripheral RM or AZ MK at last control point
    *85*,*86*, as applicable, for last control point

    Fixed Control Data (*90*) Records:
          
    *90* for each control point published by the NGS.


PROJECT DATA RECORDS
                     
    *10* - Project Title Record
    *11* - Project Title Continuation Record
    *12* - Project Information Record
    *13* - Geodetic Datum and Ellipsoid Record
        
The project data records, identified by *10*-series data codes,
are listed
above.  The *10* record which contains the title of the project is
always
required; a *11* record is required only if the project title
exceeds the
70-character field allowed on the *10* record.  Do not divide
words between the *10* and *11* records.  The *12* record, which
contains the date and general location of the survey, the survey
method employed and the order classification of the survey, is
always required.  The *13* record defines the geodetic datum with
respect to which geodetic positions, deflections of vertical,
geoid heights, and/or ellipsoidal distances given in this project
are specified.  This record is required only if the geodetic datum
is other than the North American Datum of 1983 (NAD 83).  The
entries on these records (see FORMAT DIAGRAMS) are self-
explanatory; however, the following data items will be explained
in greater detail:

    Project Title:  The elements of a good horizontal control
    survey project
title should include (1) the order of accuracy of the survey, (2)
the type of the survey, and (3) the geographic locality of the
survey.  Since the first two elements are coded elsewhere (*12*
record), only the geographic locality of the survey needs to be
spelled out in the title.  The use of geographic locality alone
for the title of a horizontal control survey project has
traditionally been the practice of NGS and its predecessors.

                                2-5
In general, the title by which the project is known to the
submitting agency should be used, supplemented to reflect
geographic locality, as required.  If the project is best
described as covering an area network (triangulation or trilat-
eration), give the geographic locality covered by the survey
(e.g., KING COUNTY).  If the project is generally linear such as
an arc of triangulation or trilateration, or a traverse which is
not confined within one locality, then give the geographic
localities of its endpoints, in the order of the progress of the
survey (e.g., CHARLESTON  TO CAPE ROMAIN). Unless it is a part of
the geographic locality name, omit the state or country
designation if only one state or country is involved.  This
information will be coded on the *12* record. Otherwise, use
abbreviations listed in ANNEX A.  Omit commas, periods, etc., and
abbreviate in the interest of fitting the entire title on the *10*
record, if possible.

    Survey Method:  A one-digit code is provided on the *12*
record to specify the survey method used - triangulation (1),
trilateration (2), traverse (3), or GPS (4).  For horizontal
control survey projects in which more than one survey method is
prominent, enter the code for that survey method which best
character-izes the project as a whole.

    Order and Class of Survey:  A two-digit code is provided on
the *12*
record to specify the order of accuracy of the survey.  The first
digit of
this code reflects the order and the second digit the class of the
survey 
in accordance with the Standards and Specifications for Geodetic
Control Networks, prepared and published by the Federal Geodetic
Control Committee (FGCC), Rockville, MD (September 1984).  In
addition to the five horizontal control survey categories defined
in this publication, two other survey categories need to be
considered - surveys of the Trans-Continental Traverse (TCT) type,
and surveys of lower-than-third-order accuracy.  The respective
two-digit codes are as follows:
                         
                     AA - AA Order Interferometric Positioning
                     A0 - A Order Interferometric Positioning
                     B0 - B Order Interferometric Positioning
                     00 - Trans-Continental Traverse
                     10 - First Order
                     21 - Second Order Class I              
                     22 - Second Order Class II
                     31 - Third Order Class I
                     32 - Third Order Class II            
                     40 - Lower Than Third Order

The order-and-class code assigned to a horizontal control survey
project should reflect the procedures and specifications by which
the main-scheme network was observed.  It is understood that many
times there are supplemental control points and intersected
landmarks to which observations of a lesser order of accuracy are
made.

When well-defined parts of a project fall into different order-
and-class   
categories, consideration should be given to dividing the project
accordingly and submitting the parts as individual projects.  If
this is not practical, assign an order-and-class code to the
entire project which corresponds to the highest order of accuracy
observed (i.e., if networks of both lst Order and 2nd Order Class
I appear in a horizontal control survey project, assign order-and-
class code 10 to the project as a whole).  In this case, however,
special care 

                                2-6
must be taken to correctly identify the order and type of each
horizontal control point on the corresponding *80* or *81* record,
according to which order of accuracy main-scheme network the
control point belongs - see section entitled SURVEY POINT DATA
RECORDS and also see ANNEX E.


DATE AND TIME

The date the HZTL OBS data set was created must appear on the Data
Set Identification Record, and the dates on which survey
operations commenced and
terminated must be entered on one of the project data records
(*12* record).  In addition, character fields for the date and
time of observation are provided on all observation data records. 
Throughout the HZTL OBS data set, date and time are to be coded as
follows:

    Date:  The full date is coded as an eight-digit integer number
consisting of four two-digit groups denoting (from left to right)
the last whole century, number of full years since the last turn
of century, month of the year, and day of the month (CCYYMMDD). 
When the century is omitted, the date is coded as a six-digit
integer number denoting the year, month, and day (YYMMDD).  If the
day is not known, leave the last two columns of the field blank;
if the month is not known, leave the last four columns of the
field blank.  For example, 8 February 1970 would be coded as
follows:

        1.  Full date is known:               19700208  or    7002
                                                              08
        2.  Day of the month is not known:        197002    or
                                                      7002
        3.  Month of the year is not known:   1970        or  70

        NOTE:  The full date for GPS data will be coded as a six-
        digit integer
        number containing three two-digit groups denoting (left to
        right) the
        number of full years since the last turn of the century,
        month of the
        year, and the day of the month (YYMMDD).
    
    Time:  A five-character field is reserved for the time of day
    on each
observation data record.  The time of day is coded as a four-digit
integer number consisting of two two-digit groups denoting (from
left to right) the hours and minutes of a 24-hour clock (HHMM), to
be entered in the leftmost four columns of the field.  The last
column of the five-character time field is reserved for the
appropriate one-letter time zone designation(see below).  Except
for GPS observations, the local zone time is to be used; in this
manner ambiguities are avoided concerning the date, which is
always assumed to be the "local" date (i.e., the date changes at
local midnight).

        NOTE:  The time of GPS data must be in Universal
        Coordinated Time (UTC), otherwise known as Greenwich Mean
        Time (GMT) or ZULU time.  

    Time Zone:  A time zone is a geographic region in which
    uniform time
differing by an integer number of hours from the Greenwich Mean
Time (GMT) is maintained by law.  In theory, a time zone extends
7-1/2 degrees in longitude east and west of a "time meridian"
whose longitude is a multiple of 15 degrees (since the Earth
rotates 360 degrees in 24 hours, 15 degrees of longitude
difference equals one hour of time difference).  In practice, the
lines which separate adjacent time zones follow political
boundaries and are therefore
rather irregular.  Associated with every time zone is a "time zone
description" - an integer number positive west of Greenwich and
negative east of Greenwich -

                                2-7
which represents the number of hours which must be added
(algebraically) to the 
local zone time in order to obtain the corresponding GMT.  The
time zone description is reduced by one hour when the standard
zone time is changed to daylight-saving time.

Instead of the numerical time zone descriptions, it is more
convenient to use the U.S. Navy one-letter codes which uniquely
identify every time zone around the world.  In this system, GMT is
the "Z" (Zulu) Time Zone.  Time zones east of Greenwich are
identified by letters A,B,C, etc., through L, with the letter J
omitted.  Time zones west of Greenwich are identified by letters
N,O,P, etc., through X.  The letter Y is used to designate the
western half of the time zone centered on the meridian of
longitude 180 degrees (International Date Line), and the letter M
is used to designate the eastern half of this zone.

The worldwide use of the time zone descriptions and of the U.S.
Navy one-letter designations is illustrated in ANNEX H.  In the
continental United States (US), Alaska (AK), and Hawaii (HI) the
time zones are as follows:          
                                                                   
 
                  TABLE 2-3 -
 U.S. NAVY TIME ZONE DESIGNATIONS         
       STANDARD      DAYLIGHT     TIME   TIME ZONE  U.S. NAVY 

         TIME
         TIME     MERIDIAN DESCRIPT'NDESIGNATION 
     Atlantic AST Eastern  EDT     60W       +4     Q
(Quebec) 
     Eastern  EST Central  CDT     75W       +5     R (Romeo) 

     Central  CST Mountain MDT     90W       +6     S
(Sierra) 
     Mountain MST Pacific  PDT    105W       +7     T (Tango) 

     Pacific  PST Yukon    YDT    120W       +8     U
(Uniform)
     Yukon    YST AK/HI    HDT    135W       +9     V
(Victor) 
     AK/HI    HST Bering   BDT    150W      +10    
W (Whiskey)
   
ͼ

If the time zone cannot be reliably ascertained, leave the last
column of the time field blank.  In this case, the time coded into
the first four columns of the time field will be interpreted as
the standard time in a zone determined on the basis of the
longitude of the survey point from which the respective        
observation was taken.


OBSERVATION DATA RECORDS      

In connection with classical survey operations, the term
"observation" is used to denote one of many angular and linear
measurements accomplished to quantify geometric relationships
among survey points.  In this context, the observations which
occur in a horizontal control survey project can be classified as
(1) horizontal directions, (2) horizontal angles, (3) vertical
angles/zenith distances/leveling, and (4) distance measurements. 
Astronomic and geodetic azimuths used for orientation control may
also be regarded as a type of observation.  The HZTL OBS data set
records which pertain to these observations are categorized as
follows:

        *20*-Series Records - Horizontal Direction/GPS Data        
  
        *30*-Series Records - Horizontal Angle Data       
        *40*-Series Records - Vertical Angle/Zenith Distance/Level
Data
        *50*-Series Records - Distance Data
        *60*-Series Records - Azimuth Data                


                                2-8
Although the GPS data records are not observations as defined
here, they are used in conjunction with observational phase
measurements to derive the Data Transfer Records (ANNEX N).        
        
The basic element of an observation is a numerical value
expressing the  measured quantity in appropriate units of
measurement.  The units of measurement used consistently for all
observations in the HZTL OBS data set are (1) sexagesimal degrees,
minutes, seconds, and decimals of a second of arc for angular
observations, and (2) meters and decimals of a meter for distance
measurements.  In addition to the respective measured quantity,
other elements necessary to describe a horizontal control survey
observation are (1) the type of observation, (2) the identity of
the survey points from which and to which the observation is taken
(standpoint and forepoint - see below), and (3) an estimate of the
accuracy of the measured quantity.  At times, auxiliary
information such as the time of the observation and the height of
the instrument  and/or target are required in order to obtain
proper spacial relationships.

The type of observation is specified by the data code of the
record.  The survey points associated with an observation are
identified by unique, job-specific station serial numbers (see
below).  A reliable, specific estimate of the overall accuracy of
a horizontal control survey observation is rarely at hand.
However, a generalized accuracy estimate can be inferred from
several data items which are normally available - the order and
class of survey, the type of survey equipment used, the number of
replications (independent measurements) taken, and the rejection
limit enforced.  With the exception of the Job-Specific Instrument
Number (see below), the observation data items related to the
estimate of accuracy of a horizontal control survey observation
will be treated in the section entitled ACCURACY OF THE
OBSERVATIONS.

Several data items which appear on the observation records are
treated below.  Detailed explanation of other observation data
items is given elsewhere in this chapter.

    Standpoint and Forepoint:  In connection with a horizontal
control survey 
observation, the point from which the observation is taken (e.g.,
the point which is occupied with a surveying instrument) will be
referred to as the "standpoint" or "instrument station."  The
point to which the observation is taken (e.g., the point to which
the foresight is directed) will be referred to as the "forepoint"
or "target station."

    Station Serial Number:  For the purpose of identifying the
standpoint and forepoint on the observation records in a concise
manner, each survey point (control point or peripheral point) is
assigned a job-specific station serial number in the range 0001 to
9999.  See Chapter 1 for a detailed explanation of the survey
point numbering system.  See also the next section entitled
ASSIGNMENT OF STATION SERIAL NUMBERS.










                                2-9
    Weather Code:  Where applicable, five adjacent integer fields
have been reserved on the observation records for one-digit codes. 
These will be referred to collectively as the "weather code."  The
first of these codes is a general problem indicator, which should
be the digit "0" under normal conditions or the digit "1" if a
problem was encountered during an observation, in which case the
problem must be explained on one or more comment records to
immediately follow  the observation record.  The other four one-
digit codes are indicators of visibility, temperature, cloud
cover, and wind, in that order.  These indicators may assume the
values 0, 1, or 2 (see Table 2-4 below).  Any one of these five
indicators may be left blank if the condition it represents is
either not known or not applicable.  

                           TABLE 2-4 -
 WEATHER CODE                 
       
ͻ 
         CODE
***           0              1              2      
       
͹
         PROBLEM         No Problem          See        Not    

         INDICATOR     Encountered      Comment         Used   
 
       
Ķ
         VISIBILITY     Good            Fair       Poor     
        
INDICATOR     (Over 15MI)   (7MI to 15MI)  (Under 7MI)  
       
Ķ
         TEMPERATURE   Normal Range     Hot            Cold    
                   
INDICATOR    (32~F to 80~F)  (Over 80~F)   (Below 32~F) 
      
Ķ
          CLOUD COVER      Clear        Partly Cloudy   
Overcast     
        
INDICATOR     (Below 20%)    (20% to 70%)   (Over 70%)  
       
Ķ
          WIND           Calm         Moderate *     Strong **
                    INDICATOR     (Under 5MPH)
(5MPH to 15MPH) (Over 15MPH) 
       
ͼ
          *No effect on observations. **Possibly affecting
observations.
          ***Blank if the condition is not known or not
applicable.

    Job-Specific Instrument Number:  The instrument used to
accomplish a horizontal control survey observation must be known;
the type of survey
equipment (i.e., its resolution and expected accuracy) will be
used to compute a standard error for the observation.  In order to
identify the instrument on 
the respective observation record in a concise manner, a unique
three-digit 
number in the range 001 to 999 is to be assigned to each item of
survey equipment used in the job.  In cases where this may be
impractical, a three-digit instrument number may be assigned to a
class of survey equipment (e.g., all 100-foot uncalibrated steel
tapes could be treated as one "instrument"), it being understood
that such a class label must correctly reflect the type,
resolution, and expected accuracy of all instruments covered by
it.

In a manner analogous to the assignment of station serial numbers,
the
instrument numbers are to be unique throughout a job, i.e., an
item of
survey equipment which appears in more than one project in the job
must be consistently identified by the same number, while
different items of survey equipment must be identified by
different numbers throughout the HZTL OBS data set.  A *70* record
must be prepared for each item of survey equipment which has been
assigned an instrument number - see SURVEY EQUIPMENT DATA RECORDS. 
  



                               2-10
    Height of Instrument and Height of Target:  Horizontal control
survey
measurements are seldom observed literally mark-to-mark between
the survey points involved.  Normally, they are measured from a
surveying instrument mounted on a tripod, wooden stand, or survey
tower erected over the standpoint to a "target" (e.g., a survey
light, retro-reflector, or remote instrument) mounted on a similar
structure over the forepoint.   

The height of instrument (H.I.) is the vertical distance from the
top of the occupied survey mark (standpoint) to the optical center
of the surveying instrument, positive if the instrument is above
the mark, and negative if it is below the mark.  This distance is
also known as the "height of telescope." Similarly, the height of
target (H.T.) is the vertical distance from the top of the survey
mark (forepoint) to the point above or below the mark which is
used as the target for angular observations, or to the optical
center of the retro-reflector (or of the antenna system of the
remote instrument) in the case of electronic distance
measurements.  This distance is also known as the "height of
object."
        
Together with the elevation (and geoid height) of the respective
survey points, the height of instrument and the height of target
are desired data items in some horizontal control survey
observations and required in others.  For horizontal directions
and horizontal angles, the height of instrument and the height of
target are desired for the computation of skew normal and
deflection corrections.  For vertical angles and distances, the
height of instrument and the height of target are required for the
reduction of instrument-to-target measurements to mark-to-mark
values.

When the surveying instrument cannot be installed directly over
the desired 
survey point and eccentric observations which are to be reduced to
center are submitted, the height of instrument entered on the
observation record must be the vertical distance between the top
of the survey point mark to which the eccentric observations are
to be reduced and the horizontal plane passing through the optical
center of the horizontally-offset surveying instrument.  The
same considerations apply to an eccentric target, retro-reflector,
or remote instrument.

    Visibility Code:  Information concerning intervisibility
    between 
monumented control points is of great value to the local surveyor,
who is not normally prepared to build survey towers over the
control points to be occupied or sighted upon.  To allow for
recording this information, a provision was made for a one-letter
visibility code on the observation records which pertains to line-
of-sight observations.  This code indicates whether or not the
forepoint (i.e., a target which might be easily constructed over
the forepoint) can be seen from ground level (height of eye) at
the standpoint.












                                      2-11
Since reference marks, azimuth marks, and the horizontal control
point to which they belong are assumed to be intervisible at
ground level, the visibility code is further used to indicate
whether the forepoint is an RM or an AZ MK associated with the
standpoint.  The respective one-letter codes are listed below.  If
a conflict arises in the assignment of a visibility code, the
hierarchy implied by this list should be followed.  In each case,
"forepoint" is meant to describe either a natural target or a
simple target installed at height-of-eye level over the forepoint,
and "ground" implies height-of-eye level at the respective
standpoint.

       1.  N - Forepoint is not visible from ground.       
       2.  R - Forepoint is an RM associated with standpoint.
       3.  Z - Forepoint is an AZ MK associated with standpoint.
       4.  V - Forepoint is visible from ground.               

The codes R and Z are to be used only for reference and azimuth
marks which are associated with the standpoint, that is, in
connection with observations from the respective horizontal
control point to its own reference or azimuth marks, or possibly
in connection with observations taken among the reference or
azimuth marks belonging to the same control point.  When the
forepoint is an RM or AZ MK which belongs to another control
point, the codes N or V, as applicable, should be used.  The
visibility code field should be left blank if the intervisibility
between the respective standpoint and forepoint is not known.


ASSIGNMENT OF STATION SERIAL NUMBERS

The station serial number (SSN) is a four-digit number in the
range of 0001 to 9999, used to uniquely identify every survey
point which appears in an HZTL OBS data set.  The survey point
numbering system was explained in detail in Chapter 1.  To
recapitulate, a survey point is defined as any point in a survey
project which has one or more observations to it or from it.  In a
horizontal control network, a survey point is either a control
point or a peripheral point.  

    Control Points:  A control point is a survey point whose
geodetic position is to be determined by the survey project, or
whose position has been determined in a previous survey.  Examples
of a control point are (1) a monumented (or otherwise permanently
marked) triangulation, trilateration, traverse, or GPS  station;
(2) a recoverable landmark (usually an intersection station) such
as a flagpole or church spire; or (3) an unmarked (and hence
nonrecoverable) survey point which must be carried as a control
point for network integrity purposes.  A survey point which cannot
be positioned because of insufficient observations, whose geodetic
position is not available from other sources, and which does not
qualify as a peripheral point (see below) must also be treated as
a control point, in that such a survey point must be identified by
a unique, station serial number (see *82* record under RECORD
FORMATS).

Each control point in a horizontal control job must be assigned a
unique, four-digit station serial number.  When more than one
project appears in a job, care must be taken to insure that (1)
the same station serial number is assigned to a control point
which several of the projects may have in common, and that (2)
different control points are assigned different station serial
numbers throughout the horizontal control job.  The station serial
numbers assigned to control points in the OBS data set of a
horizontal control job must be the same as those used to identify
the same control points in the corresponding DESC data 
                                2-12
set.  In particular, any survey point for which a description
and/or recovery note is to be submitted in the DESC data set must
be identified by a unique, station serial number, i.e., it must be
carried as a control point in the corresponding OBS data set.

Peripheral Points:  Peripheral points are survey points in the
vicinity of a control point which are not intended for
positioning, such as reference marks and azimuth marks. These
points are still identified by unique, four-digit station serial
numbers.  Unmonumented eccentric instrument setups and eccentric
targets/reflectors are also peripheral points if the respective
observations are reduced to center.

An eccentric point, RM, or AZ MK is not always treated as a
peripheral point.  If the eccentric instrument setup or
target/reflector placement is made over a monumented (or otherwise
permanently marked) point which can serve as a control point
(e.g., when a reference mark is occupied), in many cases it will
be desirable to treat the eccentric point as another control
point. In any case, when an eccentric point is offset more than 10
meters from the respective control point, the eccentric
observations should not be reduced to center (see next section),
and the eccentric point should be treated as a control point,
whether it is permanently marked or not.

A RM or an AZ MK which has not been occupied (i.e., one which has
one or more directions, angles, and/or distances measured to it
but not from it) is a peripheral point.  But, if it is to be
positioned, treat it as another control point.  An RM or AZ MK
that is occupied as a part of the survey scheme (i.e., as an
eccentric occupation of the respective control point) should
always be treated as a distinct control point.  An RM or AZ MK
that has directions, angles, and/or distances measured from it (as
well as to it) for the purpose of verifying and/or supplementing
the observations which tie together the control point and its
peripheral points may remain a peripheral point even though the RM
or AZ MK may appear as a standpoint on an observation record in
this particular case.

The observations which establish the linkage between a peripheral
point and  
its respective control point must appear among the observation
data records.  As a minimum, the following observations are
required:

    1.  Eccentric Points:  At least one angular observation
(horizontal
direction or horizontal angle) and one distance measurement,
either from
the eccentric point to the respective control point, or from the
control 
point to the eccentric point.

    2.  Reference Marks:  At least one angular observation
(horizontal  
direction or horizontal angle) and one distance measurement from
the respective control point to the RM in question.

    3.  Azimuth Marks:  At least one angular observation
(horizontal direction or horizontal angle) and one distance
measurement from the respective control point to the AZ MK in
question.
                                                                   
      
                                                                   
                                                  



                                2-13
TREATMENT OF ECCENTRIC OBSERVATIONS

When the surveying instrument cannot be installed directly over
the desired
control point (i.e., when the control point cannot be "occupied"),
observations must be made with the instrument offset a short
distance from the intended standpoint.  Similarly, when the
target, retro-reflector, or remote instrument cannot be installed
directly over the intended forepoint, observations are made to a
target, retro-reflector, or remote instrument which is offset a
short distance from the respective control point.  When such a
condition exists, the offset point from which and/or to which the
observations are actually taken is said to be "eccentric" with
respect to the control point in question, which is referred to as
the "center."
                                                        
Eccentric observations are normally "reduced to center" as a part
of the field computation process.  A correction is computed for
each eccentric observation from the distance and direction of the
offset.  After such a correction is applied, the respective
observation ceases to be "eccentric."  For all practical purposes
it is regarded as having been taken from the intended standpoint
to the intended forepoint.  As a general rule, eccentric
observations should be reduced to center by the submitting agency
and included in the HZTL OBS data set as normal (i.e., non-
eccentric) observations.

When eccentric observations are submitted, care must be taken to
select one of the two possible methods of handling eccentric
observations which is applicable to the eccentric point in
question, and to identify the respective eccentric point
accordingly - either as a peripheral point if Method A is
applicable, or as a control point if Method B is applicable (see
preceding section for definitions of "control point" and
"peripheral point").

    Method A:  The eccentric observations are to be reduced to
center.
In this case, the eccentric point is identified as a peripheral
point.  When such a peripheral point is encountered as either a
standpoint or forepoint on an observation record, the respective
observation will be reduced to center, and the original
(eccentric) observation will not be retained.  This method is
applicable only to eccentric points which are offset no more than
10 meters from the respective control point.  For offsets of
greater than 10 meters Method B is mandatory.

    Method B:  The eccentric point is to be treated as a control
point whether permanently marked or not.  In this case, no
reduction to center is involved, as the respective observations
are not regarded as eccentric.  The eccentric     standpoint or
forepoint is identified by a unique, four-digit station serial
number just as any other control point (see preceding section). 
It is given a name (e.g., SMITH ECC, if the name of the respective
control point is SMITH), and a *80* or *81* record containing its
(approximate) geodetic position and elevation must appear among
the *80*-series records.  This method should be used for eccentric
points which are permanently marked, regardless of the offset
distance involved.  Method B must always be used for eccentric
points which are offset by more than 10 meters from the respective
control point, whether the eccentric point is permanently marked
or not.






                                2-14
ACCURACY OF THE OBSERVATIONS

For every horizontal control survey observation, an estimate of
the absolute accuracy of the measured quantity must be available
for the purpose of assigning appropriate weight to that
observation when it participates in the adjustment of the
respective horizontal control network.  The absolute accuracy of a
measurement is defined as the degree to which the result of that
measurement approximates the true value of the measured quantity. 
Since the true value of a direction, angle, or distance is not
known, it then follows that the accuracy of a horizontal control
survey observation can only be estimated (1) by comparing the
results of different measurements of the same quantity, and (2) by
analyzing the misclosures by which the measured quantities fail to
satisfy geometric conditions in the respective horizontal control
network (e.g., triangle misclosures).

A horizontal control survey observation is rarely made as a
single, isolated measurement.  Once the required surveying
equipment is set over the survey points in question, it is a
common practice to measure the same quantity (direction, angle, or
distance) several times within a short span of time, each complete
measurement being carried out according to an observation scheme
which has been carefully designed to eliminate instrumental errors
(and possibly other constant and systematic errors as well).  The
advantage of "replication" is that large blunders can be detected
and eliminated, and that the resulting group of measurements can
be treated statistical as a random sample.   

Each measurement is corrected for any known constant and/or
systematic error. Then the resulting corrected sample elements are
screened for outliers (larger-than expected random errors which
are suspected to be blunders), usually by the application of a
fixed, empirical rejection limit, and the mean of the remaining
measurements is used as the best approximation of the true value.

Assuming that the blunders and/or outliers have been eliminated,
and that        constant and/or systematic errors from all known
sources have been eliminated either by the observing procedure or
by the application of computed corrections, other errors remain,
as evidenced by a random disagreement (however small) which still
normally exists among "corrected" sample elements.  If another
sample of measurements of the same quantity is taken with the same
type of instrument but under different environmental conditions,
the mean value of the second sample will normally differ from the
first sample.  If many such samples are taken, the mean values of
the re-observed samples will be found to disagree in a random
manner as well.

The errors which remain after the blunders and outliers are
eliminated and
after the sample elements are corrected for constant and
systematic errors
are seen as random errors of two different kinds.  Random errors
of the first kind are those errors which manifest themselves as
discrepancies among the elements of a sample.  Since the presence
and general magnitude of these errors are readily apparent when
the elements of the sample are compared, random errors of the
first kind are known as "sample-internal" or "internal" errors. 
Random errors of the second kind are those errors which remain
constant for all measurements within a sample but vary in a random
manner for samples which are reobserved under different
conditions.  Since they introduce the same bias into every
measurement in the sample, the presence and general magnitude of
these errors become apparent only when the mean values of several
reobserved 
samples are compared, or when misclosures of geometric conditions
in the 

                                2-15
respective horizontal control network are analyzed.  Because of
this fact, random errors of the second kind are known as "sample-
external" or "external" errors.

The accuracy estimate needed to determine the proper weight for a
horizontal control survey observation is the standard error
(sigma) reflecting the
combined effect of the internal and external errors which affect
that observation.  Such an estimate of the total uncertainty
associated with the respective measured quantity is given by the
vector sum (square root of the sum of squares) of the one-sigma
estimates reflecting the contributions of the corresponding
internal and external errors.          
                                         
A direct estimate of the contribution of the respective internal
errors (i.e., the Internal Consistency Sigma - see below) can be
obtained as the standard deviation of the computed sample mean; a
value based upon experience may be given when the sample size is
one.  If no value is specified on the respective observation
record (i.e., the field is left blank), a one-sigma estimate can
be obtained as a function of the rejection limit and number of
replications, or from a default value based on the type of survey
equipment used, number of replications taken, and on the order-
and-class of the survey.

A direct estimate of the contribution of the respective external
errors (i.e., the External Consistency Sigma - see below) is
rarely at hand, as horizontal control survey observations are not
normally re-accomplished by design under different environmental
conditions for the purpose of evaluating the effect of the
external errors.  A value based on experience may be given;
however, if no value is specified on the respective observation
record (i.e., the field is left blank), a default value based on
the survey equipment used, order-and-class of the survey, and on
the type of the survey points involved will be assigned.  In
connection with triangulation projects, a collective estimate of
the external error affecting horizontal directions (or horizontal
angles) in that project will be recovered from the set of triangle
misclosures when that project is first adjusted by NGS.

The data items which pertain to the accuracy estimate of the
respective
horizontal control survey observation not treated elsewhere in
this chapter
are defined below.

    Number of Replications:  Number of independent measurements of
    the same
quantity, normally carried out within a short span of time (i.e.,
under the 
same environmental conditions) by the same personnel using the
same equipment (i.e., sample size).  In connection with horizontal
control survey observations, it is the number of times a complete
measurement procedure (observing scheme) is executed with the
objective of obtaining a group of measurements the mean value of
which is to be used as the observed quantity (e.g., number of
positions in a set of horizontal directions).

    Rejection Limit:  Maximum variation allowed in a group of
    measurements.
The individual measurements which exceed this limit are normally
dropped from the sample and hence do not enter into the
computation of sample mean.  For horizontal directions and
horizontal angles, the rejection limit is expressed as the maximum
deviation of the individual measurements from the respective
sample mean.  For vertical angles and for distance measurements,
the rejection limit is expressed as the maximum spread between the
individual observations included in 
the sample (i.e., maximum range).

                                2-16
    Internal Consistency Sigma:  One-sigma estimate reflecting the
    contribution
of the sample-internal random errors to the total uncertainty
associated with a measured quantity.  In connection with
horizontal control survey observations, a direct estimate of the
effect of the respective internal errors is usually available as
the standard deviation of the computed sample mean.  See
discussion above concerning the treatment of the accuracy estimate
of an observation for which this data item is missing.

    External Consistency Sigma:  One-sigma estimate reflecting the
    contribution
of the sample-external random errors to the total uncertainty
associated with a measured quantity.  In connection with
horizontal control survey observations, a direct estimate of the
effect of the respective external errors is not normally
available; however, a value based on experience may be given.  See
discussion above concerning the treatment of the accuracy estimate
of an observation for which this data item is missing.

                                                        
HORIZONTAL DIRECTION DATA RECORDS                                  
           

          *20* - Horizontal Direction Set Record
          *21* - Horizontal Direction Comment Record (Optional)
          *22* - Horizontal Direction Record
                                                        
The horizontal direction data records, identified by *20*-series
data codes,
are listed above; the block diagrams depicting the respective
formats
will be found under FORMAT DIAGRAMS.
                                                       
Since one horizontal direction by itself is meaningless,
horizontal directions must be observed in sets of two or more
directions.  The respective 
observations are normally recorded in a field record book and
later abstracted onto a standard form which is usually referred to
as the "abstract of
horizontal directions."  As recorded on the "abstract," each
direction consists of a group of "pointings" observed clockwise
from the "initial" (direction to the first object sighted in the
observing sequence), which is normally assigned a value of zero. 
For each forepoint included in the set, the horizontal direction
value desired is the mean value of the respective group of
pointings (in sexagesimal degrees, minutes, seconds, and decimals
of second), corrected for eccentricity of the instrument and/or
target, if applicable (see TREATMENT OF ECCENTRIC OBSERVATIONS).
                                                        
Each set of horizontal directions is to be submitted as a group of
records which must begin with one *20* record.  In addition to
containing information which pertains to the set as a whole, the
*20* record also contains the data items associated with the
initial direction.  Following the *20* record, there may be one or
more *21* comment records.  These comment records are optional,
except when the problem indicator flag on the *20* record (first
digit of the weather code) is "1", in which case at least one *21*
record containing an explanation of the problem encountered is
required.

After the *21* record(s), or immediately after the *20* record if
no *21* record(s) are present, one or more *22* records must
follow, one for each additional direction observed in the set. 
Each of these *22* records must have the same standpoint
designation and set number (see below) as the *20* record of that
horizontal direction set.    


                                2-17
When two or more sets of horizontal directions are observed at the
same station, each set must be submitted as a separate, complete
group of *20*-series records (i.e., a *20* record, one or more *21*
records if applicable, followed by one or more *22* records).  All
sets observed at the same station must be assigned different set
numbers and must appear as consecutive sets in the order of
increasing set numbers among the *20*-series records.
  
    Set Number:  The first set of observations associated with a
    survey control
point is normally coded as 01.  Subsequent sets are coded 02, 03,
etc.  Deviation from this procedure should be explained either in
the comment records or in the transmitting letter to prevent someone
unfamiliar with the original coding to think that the records were
not coded or lost.  Sets observed at peripheral eccentric points are
considered to belong with the control point and must be numbered as
if observed at the control station.  Again, the set numbers of
successive sets of horizontal directions observed at the same
station (including peripheral stations) need not be consecutive, but
they must be assembled in increasing order.

    Number of Objects Sighted in This Set:  The number of forepoints
    to which
directions were observed in the set of horizontal directions,
including the
initial equals the number of objects sighted in the set.  This
number minus one is equal to the number of *22* records which must
appear behind the *20* record in that set.

    Date and Time:  The date of observation is required (at least
    the year) and
must appear on every *20* record.  The time of observation, when
available, is   desired to indicate the approximate time of day; any
time associated with the set of horizontal directions (e.g., time of
first observation, mean time of the set, etc.) is acceptable.  Both
date and time become required items when one attempts to set
parameters for an adjustment based upon date and time constraints.


GLOBAL POSITIONING SYSTEM DATA RECORDS

    *25* - GPS Occupation Header Record
    *26* - GPS Occupation Comment Record (Optional)
    *27* - GPS Occupation Measurement Record
    *28* - GPS Clock Synchronization Record
    *29* - GPS Clock Synchronization Comment Record (Optional)

The Global Positioning System records, identified by the *25* - *29*
data codes, are listed above; the block diagrams illustrating the
respective formats will be found under FORMAT DIAGRAMS.

Whereas observations of classical survey operations are recorded in
ASCII format in this text, GPS observations containing code and
phase data are recorded by the GPS receiver in a binary format that
is unreadable without a translation (e.g., vector reduction)
program.  The information on the *25* to *29* records and the GPS
code and phase measurements are required to derive the information
in the GPS Data Transfer Format file (G-File) records:
A,B,C,D,E,F,G,H (ANNEX N).

A set of one *25* and two *27* records must exist for each
independent occupation of a control point by a GPS receiver.  The
first *27* record indicates the time data recording was initiated
plus associated occupation information; the second *27* indicates
the time data recording was completed plus associated occupation
information.  Record the time and date referenced to UTC (or
Greenwich Mean Time).

                                2-18
A *28* record, used with older receivers which do not recover time
from the broadcast GPS signal, is required whenever GPS receivers
must be time synchronized to the external time source, e.g., another
receiver or a master time source.  When using these "codeless"
receivers, synchronization must be established between all receivers
taking simultaneous measurements.  Two synchronizations, normally
one before and one after collecting the GPS observations, are
required to check receiver clock drift and to verify that no time
synchronization errors ("jumps") occurred during the observing
period.  The *28* record is not required for modern P-code receivers
which may be referred to as codeless when in anti-spoofing mode.

The station serial number, weather code, and job-specific instrument
number fields are required on GPS records.  These entries are fully
explained in the section, OBSERVATION DATA RECORDS.  Other entries
in the GPS records are self explanatory.

Job-Specific Data Media Data Identifier:  Since the GPS observables
(code and phase data) can not be practically accommodated in the
formats of this text, they must be submitted in manufacturer
specific or RINEX (Receiver Independent Exchange) data file formats. 
Depending upon the receiver type, one or more files may be
generated.  However, it is still necessary to associate a specific
set of data file(s) to a specific occupation.  This is done by the
user who assigns a 10 character identifier for each station
occupation.  These identifiers are unique to a specific project and
reflect information on the physical or digital labels of the phase
data files.  The sole function of the data media identifier is to
provide to NGS a one-to-one correspondence between a control point
occupation and a GPS data file.  The standard format for the data
media identifier can be found in ANNEX N.

Antenna Height:  The antenna height is the vertical distance from
the indicated point of the occupied survey mark to the L1 phase
center of the antenna.  Slant, slope or offset heights are not
acceptable.

HORIZONTAL ANGLE DATA RECORDS

        *30* - Horizontal Angle Set Record
        *31* - Horizontal Angle Comment Record (Optional)
        *32* - Horizontal Angle Record
        
The horizontal angle data records, identified by *30*-series data
codes,
are listed above; the block diagrams illustrating the respective
formats
will be found under FORMAT DIAGRAMS.                                 
                                                         
Horizontal angles (clockwise), as opposed to horizontal directions,
are normally observed in connection with surveys of low accuracy
(e.g., third order or lower) using repeating theodolites and
engineer's transits.  The characteristic feature of these
instruments is the double concentric motion about the vertical axis
by means of which the horizontal circle can be set precisely to zero
when one of 
the forepoints is sighted upon, and the desired horizontal angle to
another forepoint can be "repeated"; i.e., measured several times in
succession, each 
time allowing the horizontal circle reading to be incremented by the
magnitude of the measured angle.  The desired angular measure,
expressed to a greater precision than the resolution of the
respective instrument, is obtained when the total angle accumulated
on the horizontal circle is divided by the number of "repetitions."

The number of repetitions must not be confused with the number of
replications, as one angle measurement by this method, involving any
number of repetitions, constitutes but one determination of that
angle (i.e., one replication).

                                 2-19
Normally, several such determinations are made; the desired
horizontal angle value is the mean value of the respective group
of measurements (in sexagesimal degrees, minutes, seconds, and
decimals of second), corrected for eccentricity of instrument
and/or target, if applicable (see TREATMENT OF ECCENTRIC
OBSERVATIONS).  Two forepoints are involved with every horizontal
angle observation; the value given must be the clockwise angle
from the first (left) forepoint to the second (right) forepoint.

Since a horizontal angle is a complete observation in itself,
every horizontal angle may be submitted as a "set of size one,"
i.e., as a *30* record followed by one or more *31* comment
records.  These comment records are optional, except when the
problem indicator on the *30* record (first digit of the weather
code) is 1, in which case at least one *31* record containing an
explanation of the problem encountered is required.  When more
than one angle is measured as a part of the same observing scheme
(e.g., angle observation by Schreiber's method), the additional
angles in the same set should be submitted as *32* records to
follow after the *31* record or records, or immediately after the
*30* record if no *31* records are present.  In addition to the
same standpoint designation, each of these *32* records must bear
the same set number (see below) as the *30* record of that
horizontal angle set.

When two or more sets of horizontal angles are observed at the
same station, each set must be submitted as a separate, complete
group of *30*-series records (i.e., a *30* record, one or more
*31* records if applicable, followed by one or more *32* records). 
All sets observed at the same station must be assigned different
set numbers and must appear as consecutive sets in the order of 
increasing set numbers among the *30*-series records.  If
horizontal angles are to be reduced to center, the sets observed
at peripheral eccentric points of the same control point must
appear as members of the same sequence together with any set or
sets observed directly over the corresponding control point.

    Set Number:  Normally coded as 01, unless two or more sets of
    horizontal
angles observed at the same standpoint (either between the same or
between different forepoints), in which case these sets must
appear adjacent among the horizontal angle data records.  The
first set in the sequence must be assigned a two-digit set number,
e.g., 01, and each additional consecutive set bearing the same
standpoint designation must be assigned a higher number, e.g., 02,
03, etc.  For this purpose, sets observed at peripheral eccentric
points are considered to belong with the respective control point
and must be grouped accordingly. The set numbers of successive
sets of horizontal angles observed at the same station need not be
consecutive; however, they must be increasing.

    Number of Angles Observed in This Set:  Total number of
horizontal angles observed as a part of the same observing scheme. 
This number minus one equals the number of *32* records which must
appear behind the respective *30* record in that set.

    Date and Time:  Date of observation is required (at least the
year) and must appear on every *30* record.  Time of observation,
where available, is desired to indicate the approximate time of
day; any time associated with the horizontal angle observation
(e.g., starting time, mean time, ending time, etc.) is acceptable. 
Both date and time become required items when one attempts to set
parameters for an adjustment based upon date and time constraints.



                                2-20
VERTICAL ANGLE/ZENITH DISTANCE DATA RECORDS

              *40* - Vertical Angle Set Record
              *41* - Vertical Angle Comment Record (Optional)
              *42* - Vertical Angle Record


The vertical angle/zenith distance data records, identified by
*40*-series data codes, are listed above; the block diagrams
illustrating the respective formats will be found under FORMAT
DIAGRAMS.  

Vertical angles (or zenith distances) are observed in connection
with classical horizontal control survey projects for the purpose
of obtaining elevation differences between horizontal control
points by trigonometric leveling.  The elevation of one or more of
the survey points involved must be reliably known from some other
source.

In addition to vertical angles and distances between survey
points, the determination of the elevation differences by
trigonometric leveling requires a knowledge of the geoid height at
every survey point involved and of the deflection of vertical in
the direction of each vertical angle observed at every standpoint. 
Since geoid heights and deflections of the vertical are seldom
known, it is a common practice to assume a zero value for these
quantities, and therefore only approximate results can normally be
obtained.  For this reason, vertical control should not be
extended by this method without frequent ties to existing bench
marks in the project area.  Aside from the difficulties mentioned
in the preceding paragraph, trigonometric leveling suffers from a
large uncertainty due to atmospheric refraction.  This uncertainty
is brought about by the unpredictable nature of the irregular,
preponderantly vertical bending of an optical ray due to the
variation of the refraction gradient along its path.  This effect
of atmospheric refraction is the dominant source of the external
random error associated with vertical angle observations.  To
control the influence of this external error, the magnitude of
which grows with the length of the observed line, reciprocal
vertical angles are often observed simultaneously or nearly
simultaneously from both ends of the respective line.

In a manner similar to other types of horizontal control survey
observations, a vertical angle is usually measured several times
in rapid succession following a standard observing scheme.  The
desired vertical angle value is the mean value of the respective
group of measurements (in sexagesimal degrees, minutes, seconds,
and decimals of second) accompanied by the appropriate angle code
(see below) which identifies the value given as an elevation angle
(E), depression angle (D), or a zenith distance (Z).  Since the
magnitude of the dominant external error affecting the vertical
angle measurement is proportional to the length of the observed
line (see above, the respective External Consistency Sigma is
expressed as seconds of arc per kilometer.)

A vertical angle is a complete observation in itself; hence every
vertical
angle may be submitted as a "set of size one," i.e., as a *40*
record
followed by one or more *41* comment records.  These comment
records are
optional, except when the problem indicator on the *40* record
(first digit of the weather code) is 1, in which case at least one
*41* record containing an explanation of the problem encountered
is required.  When two or more vertical angles to different
forepoints are measured at a station as a part of the same
observing scheme, the additional vertical angles in the same set
should be 

                               2-21
submitted as *42* records to follow after the *41* record or
records, or immediately after the *40* record if no *41* records
are present.  In addition to the same standpoint designation, each
of these *42* records must bear the same set number (see below) as
the *40* record of that vertical angle set.

When two or more sets of vertical angles are observed at the same
station, each set must be submitted as a separate, complete group
of *40*-series records (i.e., a *40* record, one or more *41*
records if applicable, followed by one or more *42* records).  All
sets observed at the same station must be assigned different set
numbers and must appear as consecutive sets in the order of 
increasing set numbers among the *40*-series records.  For this
purpose, sets observed at peripheral eccentric points of the same
control point must appear as members of the same sequence together
with any set or sets observed directly over the corresponding
control point.

    Set Number:  Normally coded as 01, unless there are two or
more sets of vertical angles observed at the same standpoint
(either to the same or to different forepoints), in which case
these sets must appear adjacent among the vertical angle data
records.  The first set in the sequence must be assigned a two-
digit set number, e.g., 01, and each additional consecutive set
bearing the same standpoint designation must be assigned a higher
number, e.g., 02, 03, etc.  For this purpose, sets observed at
peripheral eccentric points are considered to belong with the
respective control point and must be grouped accordingly.  The set
numbers of successive sets of vertical angles observed at the same
station need not be consecutive; however, they must be increasing.

    Number of VAs or ZDs Observed in This Set:  Number of
forepoints to which vertical angles (or zenith distances) were
observed as a part of the same observing scheme.  This number
minus one equals the number of *42* records which must appear
behind the respective *40* record in that set of vertical angles.
    
    Date and Time:  Date of observation is required (at least the
year) and
must appear on every *40* record.  The full date and the time of
the vertical
angle observation to each forepoint involved should be supplied
whenever
possible, so that any search based on date and time can be made
for
simultaneous or nearly simultaneous reciprocal vertical angle
observations.
For this purpose, a time field appears on the *42* record as well
as on the
*40* record.  

    Angle Code:  Vertical angles are measured with respect to the
direction of the gravity vector at the respective standpoint by
theodolites or transits equipped with appropriate vertical
circles.  Depending on the instrument, the origin (zero graduation
mark) of the vertical circle points either in a direction
perpendicular to that of the gravity vector, in which case the
origin of the vertical circle lies in the local astronomic
horizon, or else it points in the direction opposite to that of
the gravity vector, in which case the origin of the vertical
circle indicates the local astronomic zenith.

When the zero of the vertical circle defines the astronomic
horizon, the 
vertical angle measured is an "elevation angle" or a "depression
angle" depending on whether the object sighted is above or below
the astronomic horizon.  When the zero of the vertical circle
points in the direction of the astronomic zenith, the vertical
angle measured is a "zenith distance."  The zenith distance of an
object above the astronomic horizon will be less than 90 


                               2-22
degrees, while the zenith distance of an object below the
astronomic horizon 
will be greater than 90 degrees.

The angle code is a one-letter indicator of the type of the
vertical angle
given.  The three possible codes are as follows:

                       E - elevation angle
                       D - depression angle
                       Z - zenith distance


LEVEL DATA RECORDS 

    *45* - Observed Difference of Elevation Records
    *46* - Observed Difference of Elevation Comment Record
    *47* - Observed Difference of Elevation Continuation Record

The difference of elevation data records, identified by *40*-
series data codes, are listed above; the block diagrams
illustrating the respective formats will be found under FORMAT
DIAGRAMS.  Differences of elevation are observed in connection
with classical horizontal control survey projects in order to
maintain an observed difference of elevation relationship between
two horizontal control points for the purpose of data reduction. 
Both horizontal control points generally do not have established
vertical elevations.  However, either one of these two control
points could already have an established and published elevation. 


In a manner similar to other types of horizontal control survey
observations, a difference of elevation is usually measured at
least twice (once in the forward direction and once in the reverse
or backward direction) as standard observing practice.  The
desired difference of elevation is then the mean value of the two
respective differences of elevation.  However, each level running
(i.e., forward and backward) can be considered as an independent
observation and can be coded as a separate observed difference of
elevation data set.

Since a difference of elevation is a complete observation in
itself, each observation is submitted as a *45* record, followed
by one or more *46* comment records, followed by a *47* record. 
The comment records are optional, except when the problem
indicator on the *45* record (first digit of the weather code) is
1, in which case at least one *46* record containing an
explanation of the problem encountered is required.  The *47*
record must bear the same standpoint designation as the *45*
record preceding it.

When two or more sets of differences of elevation are observed at
the same station, each set must be submitted as a separate,
complete group of *40*-series records (i.e., a *45* record, one or
more *46* records if applicable, followed by a *47* record).

    Number of Replications:  The number of replications for a
single difference of elevation observation is one.  If the
difference of elevation is the mean
value of two level runnings of the same section (i.e., forward and
backwards) then the number of replications is coded as 2.




                                2-23
    Date and Time:  The date of observation is required (at least
the year) and must appear on every *45* record.  The full date and
time for the leveling observation should be supplied whenever
possible.  The observation time coded should be the mid-time for
the running of the section. 


DISTANCE DATA RECORDS

             *50* - Taped Distance Record
             *51* - Unreduced Distance Record
             *52* - Reduced Distance Record
             *53* - Unreduced Long Line Record
             *54* - Reduced Long Line Record
             *55* - Distance Comment Record (Optional)

The distance data records, identified by *50*-series data codes,
are listed
above; the block diagrams illustrating the respective formats will
be found
under FORMAT DIAGRAMS.

Submit a *50*, *51*, *52*, *53*, or *54* record, followed by one
or more *55* comment records, for every distance determination in
the horizontal control survey project.  The comment records are
optional, except when the problem indicator (first digit of the
weather code) is 1, in which case at least one *55* record
containing an explanation of the problem encountered must follow
the respective *50*, *51*, or *52* distance record.  The weather
code has been omitted on the *53* and *54* long-line records.  In
every case, the desired distance value is the mean value of the
respective group of replicated measurements to which all
corrections applicable to that type of distance measurement have
been applied (in meters and decimals of meter), further corrected
for eccentric setup at either end of the measured line, if
applicable (see TREATMENT OF ECCENTRIC OBSERVATIONS).  It must be
accompanied by the appropriate distance code (see below) which
identifies the distance value given as to its type.

The *50* record is intended for distances measured with either
calibrated or uncalibrated (i.e., standardized or not
standardized) steel or invar tapes. Included are distances
consisting of any number of segments taped horizontally, taped
distances consisting of any number of segments which have all been
reduced individually to a common horizontal reference surface
(other than the sea level or the ellipsoid), and one-segment
unreduced taped distances (less than or equal to one tape length)
measured along a slope.  The limitation to only one segment in
this last case is forced by the additional data items (the
elevation difference between the respective marks and the heights
of tape supports over the marks) required for each such taped dis-
tance segment.  Excluded are taped distances which have been
reduced to sea level (geoid), to the ellipsoid, or to mark-to-
mark, for which the *52* record should be used.  In every case,
the respective standardization, catenary, and temperature
corrections, as applicable to the method of measurement and/or to
the equipment used, are assumed to have been applied.

The *51* record is intended for unreduced slant-range distances
under 100 kilometers measured by electronic distance-measuring
equipment (DME).  Included 
are line-of-sight instrument-to-reflector distances measured by
electro-optical DME and master-to-remote distances measured by
microwave DME with a resolution (i.e., smallest directly readable
measurement unit) of 1 centimeter or better.  

                               2-24
Excluded are distances measured to a precision coarser than 1
centimeter
(because the respective Rejection Limit, Internal Consistency
Sigma, and External Consistency Sigma should be expressed in
different units), which may be submitted as *53* records.  In
every case, the respective instrument and/or reflector calibration
corrections and refraction correction, as applicable to the method
of measurement and/or to the equipment used, are assumed to have
been applied.  

The *52* record is intended for taped distances, and for distances
under 100 kilometers measured by electronic DME with a precision
of 1 centimeter or better, which have been reduced (1) to sea
level (i.e., to the geoid), (2) to the ellipsoid (either NAD 83 or
as specified on the *13* record), or (3) to mark-to-mark.  For the
same reason given in the preceding paragraph, reduced distances
measured to a coarser precision than 1 centimeter should be
submitted as *54* records.  In every case, the distance given is
assumed to be the appropriately reduced value corresponding to the
mean of the respective sample of distance measurements to which
all applicable corrections have been applied.  Among the required
data items are elevations (and of the geoid heights, if
applicable) which were used in the reduction process (possibly
different than those provided on the corresponding *80*-series
records).

The preponderant external random errors affecting precisely taped
distances or line-of-sight distances measured by fine-resolution
electronic DME arise out of the inadequacy of the mathematical
models used to correct the respective distance measurements for
distance-dependent systematic errors, such as the temperature and
catenary corrections in case of taped distances, or the refraction
correction in case of distances measured by precise electro-
optical or electro-magnetic DME.  The magnitude of the respective
external random errors is therefore also proportional to the
length of the measured line.  For this reason, the External
Consistency Sigma on the *50*, *51*, and *52* records is expressed
as a parts-per-million (ppm) value.

The *53* and *54* records are counterparts of the *51* and *52*
records intended, respectively, for unreduced and reduced long-
line distances (100
kilometers and longer) measured with either fine or coarse
resolution by an
indirect method.  Examples of such long-line distances are the
antenna-to- antenna spatial chords and the corresponding reduced
sea-level (geoidal),
ellipsoidal, or mark-to-mark distances derived from line-crossing
measurements made with a long-range, airborne electro-magnetic DME
(e.g. HIRAN), or obtained by extraterrestrial techniques (e.g.,
VLBI).  These records may also be used, respectively, for
unreduced and reduced slant-range distances under 100 kilometers
measured directly by a coarse-resolution DME.  Since the
preponderant external random errors associated with long-line
and/or coarse-resolution distance measurements do not normally
exhibit any relationship with the length of the respective line,
the External Consistency Sigma on the *53* and *54* records is
expressed in meters.

   Date and Time:  Date of observation is required (at least the
   year) and must
appear on every distance observation record.  Time of observation,
where available, is desired to indicate the approximate time of
day; any time associated with the distance observation (e.g.,
starting time, mean time, ending time, etc.) is acceptable.




                               2-25
   Distance Code:  A one-letter indicator of the type of distance
   involved.
This indicator must appear immediately following the distance
field on the
distance observation records.  The possible distance codes are as
follows:


       1.  Unreduced Distances:

             T - distance taped horizontally                       
 
             H - taped distance reduced to horizontal
             S - slope distance or slant-range distance
             C - spatial chord distance            

       2.  Reduced Distances:

             G - sea-level (geoidal) distances
             E - ellipsoidal distances
             X - mark-to-mark distances

                      
AZIMUTH DATA RECORDS

          *60* - Laplace/Astronomic Azimuth Record
          *61* - Geodetic Azimuth Record

The azimuth data records, identified by *60*-series data codes,
are listed        above; the block diagrams illustrating the
respective formats will be found
under FORMAT DIAGRAMS.  

A Laplace azimuth is an astronomic azimuth determination (e.g., by
observation
of the star Polaris) converted to a corresponding geodetic azimuth
by the application of the Laplace correction.  A data element
necessary for the computation of the Laplace correction is the
east-west (prime-vertical) component of the deflection of vertical
at the respective standpoint.  If the deflection component is not
known from other sources, an astronomic longitude must also be
observed.  A horizontal control point at which the prime-vertical
component of the deflection of vertical is known, and at which a
determination of astronomic azimuth has been made, is called a
"Laplace station."

Laplace azimuths are the primary means for orienting a survey
project if the orientation cannot be obtained with respect to
established horizontal control points (e.g., because of
intervisibility problems).  When a survey project is extended away
from existing horizontal control, Laplace stations must be
established at regular intervals to guard against the buildup of
systematic errors which may cause a gradual swing in the
orientation of the network.
                                              
Submit a *60* record for each astronomic or Laplace azimuth used
in the project.  If there are two or more sets of astronomic
azimuth observations (e.g., sets observed on different nights),
submit a separate *60* record for each set.  The desired Laplace
azimuth is the mean value of the respective set of astronomic 
azimuth observations to which all applicable corrections,
including the Laplace correction, have been applied (in
sexagesimal degrees, minutes, seconds, and decimals of second),
further corrected for eccentricity of instrument and/or target, if
applicable (see TREATMENT OF ECCENTRIC OBSERVATIONS).

A required data item on the *60* record is the Prime-Vertical
Component of 

                               2-26
Deflection (Eta), i.e., the difference between the astronomic and
geodetic longitudes of the standpoint, as used in the computation
of the expressed Laplace correction.  In addition to its absolute
numerical value in seconds, the direction of the prime-vertical
component of the deflection of vertical, i.e., the Direction of
Eta must be specified as "E" or "W" according to whether the
astronomic longitude falls east or west of the corresponding
geodetic longitude of the standpoint.

The results of astronomic observations in the form of an
astronomic azimuth or a computed Laplace azimuth and the
meridional and prime-vertical components of the deflection of
vertical are called for on the *60* and *85* records of the HZTL
OBS data set.  In addition, the respective astronomic latitude,
longitude, and/or azimuth observations should be submitted
separately in full detail for rigorous processing and
incorporation into the astronomic data file of the National
Geodetic Survey Data Base.

Geodetic azimuths are used when orientation control for a survey
project is obtained with respect to the existing horizontal con-
trol network by including an azimuth reference object (e.g., the
azimuth mark) among the forepoints to which horizontal directions
or horizontal angles are observed at one or more existing
horizontal control points.  Such control points, occupied for the
purpose of establishing connection with the existing horizontal
control network, must be identified as "fixed" by means of *90*
Fixed Control Records (see FIXED CONTROL DATA RECORDS).

Submit a *61* record containing the respective geodetic azimuth
value (in
sexagesimal degrees, minutes, seconds, and decimals of second) for
every
azimuth reference object to which a horizontal direction or
horizontal angle has been observed for the purpose of providing
orientation control for the survey project.  But, do not submit a
*61* record if the azimuth reference object in question is another
control point in the HZTL OBS data set, i.e., if a *80* or *81*
record defining its geodetic position appears among the *80*-
series records (see SURVEY POINT DATA RECORDS).  Instead, if such
a control point is used for azimuth reference, it must be
identified as "fixed" by means of a *90* Fixed Control Record in
the same manner as the respective standpoint (see above).

    Date and Time:  The date of the astronomic azimuth observation
is required
(at least the year) and must appear on the respective *60*
Astronomic/Laplace Azimuth Record.  The time of observation is
desired to indicate the approximate time; any time associated with
the astronomic azimuth observation (e.g., starting time, mean
time, ending time, etc.) is acceptable.  Date and time have been
omitted on the *61* Geodetic Azimuth Record, since one does not
observe a geodetic azimuth.  It is a computed quantity.

    Origin of Azimuth:  A one-letter code indicating the branch of
the
meridian (north or south) with respect to which the azimuth given
on a *60*
or *61* record is specified.  The azimuth of a line joining a
standpoint and
a forepoint is defined as the clockwise horizontal angle (0 to 360
degrees)
measured from either the north or the south branch of the meridian
at the
standpoint to the forepoint in question.  Since the azimuth may be
defined  
as either "from the north" or "from the south," the origin of the
azimuth
must be specified as "N" or "S", whichever applies.  In the NAD 27
system of coordinates, astronomic and geodetic azimuths are
defined as originating from the south.  In the NAD 83 system of
coordinates, astronomic and geodetic 
azimuths are defined as originating from the north.

                                2-27
SURVEY EQUIPMENT DATA RECORDS

          *70* - Instrument Record                      
                                                                   
         
The purpose of the *70* record is to provide descriptive
information pertaining to an item of survey equipment which has
been identified by a Job-Specific Instrument Number (see under
OBSERVATION DATA RECORDS).  Submit a *70* record for each item of
survey equipment used in the project.  Individual *70* records
should appear in order of increasing Job-Specific Instrument
Numbers (JSIN).  More than one *70* record is required for any
instrument used for more than one type of measurement.  In other
words, a theodolite used to measure both horizontal and vertical
angles would require two *70* records: one to record the
resolution of the horizontal measurements and the other to record
the resolution of the vertical measurements.  The resolution and
units symbol (see below) of these two records would be different
but, the JSIN and the NGS Survey Equipment Code would be
identical.

If a "total station" type instrument is used in a survey, three
*70* records may be required (horizontal directions, vertical
angles and distance observations) for one JSIN.  If this equipment
is self-contained, the JSIN and the NGS Survey Equipment Code will
be identical in each of the three records as stated above. Refer
to the Total Station category (800-860) in ANNEX F.  But, if
modular type equipment (optional EDM instruments can be mounted on
the same "total station" base unit) is used, the NGS Survey
Equipment Code in the *70* record, which reflects the resolution
of the distance measurements, must be that of the specific EDM
instrument used for the observations.  (Refer to Distance-
Measuring Equipment categories (500-799) in ANNEX F).  The
equipment code for the other two *70* records would be listed in
the Total Station category (861-899) in ANNEX F.

Most of the entries on the *70* record (see FORMAT DIAGRAMS) are
self-explanatory; however, the following data items will be
explained in greater detail:

    NGS Survey Equipment Code:  A three-digit numerical
identification code is
assigned to the different categories of survey equipment, and
within each category to specific instruments or other items of
survey equipment commonly used in the United States - see ANNEX F.

    Resolution of the Instrument and Units:  The size of the
smallest
directly-readable linear or angular measurement unit
characteristic of the
respective item of survey equipment, followed by a two-letter
symbol for
the units in which it is expressed:

              MT - meters         HS - horizontal seconds of arc  

              MM - millimeters    HM - horizontal minutes of arc
              FT - feet           VS - vertical seconds of arc
              MF - millifeet      VM - vertical minutes of arc

The character fields reserved for Resolution of the Instrument and
for
Units on the *70* record may be left blank if the resolution of
the surveying instrument in question cannot be expressed in these
units (e.g., if the
measurement is obtained in terms of arbitrary "dial" units which
do not   
bear a fixed relationship to the measured quantity).
                       

                               2-28
SURVEY POINT DATA RECORDS                                          
           

          *80* - Control Point Record 
          *81* - Control Point Record (UTM/SPC)
          *82* - Reference or Azimuth Mark Record
          *85* - Deflection Record (Optional)
          *86* - Orthometric Height, Geoid Height, Ellipsoid
          Height Record

The survey point data records, identified by *80*-series data
codes, are
listed above; the block diagrams illustrating the respective
formats will
be found under FORMAT DIAGRAMS.

Submit a group of *80*-series records for every control point
which appears
in the horizontal control survey project.  See ASSIGNMENT OF
STATION SERIAL
NUMBERS for definition of "control point" and "peripheral point"
and for an
explanation of the survey point numbering system.  Start with the
control
point identified by the numerically lowest station serial number
and continue with control points in the order of their increasing
(not necessarily
consecutive) station serial numbers.

The group of *80*-series records pertaining to a control point
will usually
consist of either a *80* record or a *81* record followed by as
many *82* records as there are peripheral reference marks and/or
azimuth marks associated with the horizontal control point in
question.  Use the *80* record if the geodetic position of the
control point (see below) is given in geographic coordinates
(latitude and longitude); use the *81* record if the position is
given either in the Universal Transverse Mercator (UTM) coordi-
nates or in State Plane Coordinates (SPC).  Following the *80* or
the *81* record, submit one *82* record for each peripheral RM or
AZ MK of that control point.  Do not submit a *82* record for an
RM or AZ MK which is being treated as a control point for which a
*80* or *81* record appears elsewhere among the survey point data
records.  After the *82* records, or after the *80* or *81* record
if no *82* records are present, a *85* record may follow, followed
by a *86* record.  A *85* record should be submitted if either one
or both the meridional and prime-vertical components of the
deflection of vertical are known.  Submit a *86* record to provide
orthometric height values for all control points, except for
unmonumented recoverable landmarks positioned by intersection. 
The geoid and ellipsoid height values in this record are optional,
with one exception.  If the submitted orthometric height value was
determined by GPS observations, the associated geoid height value
is required.
  
Two special cases are recognized, in which a *82* record must be
submitted for a control point instead of the usual *80* or *81*
record.  The first case has to do with survey points which would
normally be regarded as horizontal control points (i.e., they do
not qualify as peripheral points), which cannot be positioned
because of insufficient observations, and whose geodetic position
cannot be obtained from other sources.  Such a survey point must
be identified just as a normal control point, however, since the
respective geodetic position is not available; submit a *82*
record in lieu of a *80* or *81* record, then proceed as for any
other normal control point, i.e., submit additional *82* records,
a *85* record, and a *86* record, as applicable.

The second case has to do with survey points which are used as
vertical control 
points only, i.e., bench marks or other points to which and/or
from which one or more vertical angles and distances have been ob-
served, but no horizontal 

                                2-29
directions or angles.  Survey points of this kind must also be
identified by four-digit station serial numbers.  If such a survey
point is positionable (e.g. by trilateration), then it should be
treated as a normal control point.
Otherwise, submit a *82* record for this point in lieu of a *80*
or *81* record.  A *85* record may follow, if applicable, but a
*86* record is required.  Additional *82* records are not allowed
in this set.  Should such a point have any peripheral reference or
azimuth marks, then it should be treated as in the first special
case, described in the preceding paragraph.

For the purpose of easy identification, any *82* records, used in
lieu of *80* or *81* records as described in the special cases
above, should be grouped together and sequenced to follow all the
control points with geodetic positions.

The entries on the *80*-series records (see FORMAT DIAGRAMS) are
selfexplanatory; however, the following data items will be
explained in greater
detail:                                                        

    Station Name:  In the United States, it has traditionally been
the
preferred practice at the National Geodetic Survey (NGS) and its
predecessors to assign intelligible names as primary identifiers
of horizontal control points.  Such "station names" have the
important advantage of being mnemonic - a quality which pure
numbers or arbitrary alphanumeric symbols do not possess.  In
addition, a properly chosen station name may in itself be
descriptive and/or indicative of the general location of the
horizontal control point, which is a desirable property.  For
automatic data processing purposes, however, the use of station
names as primary identifiers does pose some difficulty, in that
their length must, of necessity, be limited to a specific number
of characters, and that, contrary to common usage of intelligible
names, exactly the same abbreviation and/or spelling of the
respective station name must be used whenever a reference is made
to a horizontal control point in computer-readable media.

The name of a monumented horizontal control point is usually
concise, being     limited in length by the space which is
available on a standard disk marker
for the die-stamping of the respective station name.  The usual
practice is
to stamp the name above the survey point symbol (e.g., triangle)
which   
appears in the center of a standard disk marker, and the year
(e.g., 1935)
in which the mark was set is usually stamped below the survey
point symbol.

In addition to this "year mark set" which normally appears stamped
on every monumented survey point, another date is associated with
every horizontal control point, i.e., with every survey point
which is positioned, whether it is a monumented control point or
an unmonumented recoverable landmark (see below).  Referred to as
the "year established," it is the year in which observations were
first performed for the purpose of determining the position of
that horizontal control point; this is normally also the year in
which the original description of that control point was prepared. 
The "year established" and "year-mark-set" of a monumented
horizontal control point are often identical.

Another type of horizontal control point is an unmonumented
recoverable landmark (usually an intersection station) such as a
flagpole or church spire.  The name of a horizontal control point
of this type must be sufficiently descriptive in





                               2-30
order to identify the respective landmark (and frequently a
specific feature of the landmark) adequately, and for this reason
it is usually lengthy.

For data processing purposes in HZTL OBS data sets, the length of
a station name (including all imbedded blanks) is limited to 30
characters, and the same limit applies to the name or designation
of a reference mark (RM) or azimuth mark (AZ MK).  Accordingly,
the name of every horizontal control point to be entered on the
*80* or *81* record (as well as the name or designation of an RM
or AZ MK to be entered on the *82* record) must be abbreviated
and/or edited if it exceeds 30 characters.  Guidelines for survey
point names and designations, including recommended abbreviations,
are given in ANNEX D.  Note that the name or designation of a
bench mark (BM) is limited to 25 characters (see Vertical Control
Data, Chapters 5, 6, and 7).

For some of the lengthier names given to horizontal control points
(e.g., those of unmonumented recoverable landmarks) contraction to
30 characters will involve rather drastic abbreviation and
editing, in which process much of the desired intelligibility and
descriptiveness may be lost.  To minimize this effect in
connection with geodetic materials which are intended for use by
the general public, up to 40 characters are allowed for the name
of a horizontal control point in the GEOD DESC data set (see Chap-
ter 3).  This 40-character station name will be used in the
automated publication of geodetic data sheets, station
descriptions, and associated indexes.  This implies that two
versions for every station name which exceeds 30 characters in
length can exist - a 30-character version used for data processing
purposes, and a 40-character version used for publication
purposes.  The two versions should differ only as to the manner in
which the station name is abbreviated and/or edited.

The name of a horizontal control point entered on the *80* or *81*
record should be taken as it appears under "Station Name" in the
heading of the respective station description and subsequent
recovery notes.  For monumented horizontal control points, this
station name is normally identical to or closely resembles the
name stamped above the survey point symbol on the respective disk
marker.  Note that neither the "year established" nor the "year
mark set" normally appears as a part of the station name.  While
parts of a lengthy station name may be abbreviated or edited out
in order to conform to the 30-character limit, nothing should be
added, except as necessary to render the station name unique
within the job (see below).        

Parentheses are not permitted to appear in a station name.  Other
special
characters such as periods, commas, etc. (see Chapter 1) - as well
as any    
unnecessary spaces (blanks) - should also be edited out whenever
possible.

In the same manner as the job-specific station serial number of a
horizontal control point, that is unique within a job, it is
highly desirable to have a station name that is unique within a
job.  If two or more control points in a job are found to have
identical names, they should be rendered unique by appending to
the respective station names, in order of preference:    

   1.  The name of the county (parish, census division) in which
       the station is located, followed by the symbol CO (PA,CD) -
       Example:  JONES CLALLAM CO and JONES KING CO (SMITH ORLEANS
       PA and SMITH DE SOTO PA, ROCK KENAI-COOK INLET CD and ROCK
       ANCHORAGE CD).


                               2-31
   2.  The name of a locality other than county, parish, or census
       division - Example:  PIPE SAN ANTONIO and PIPE LACKLAND AFB.
                                                                    
              The year the mark was set is considered extraneous
information and is not to be carried as a part of a control point
name.  For marks whose names were not  altered when they were
reset, the word RESET must be appended to the original
designations.  This also holds true for control points which have
been reset more than once.  In such cases the year given in the
"year monumented" field of the description / recovery note will be
used to distinguish the marks.  See ANNEX D for additional
information and examples.

Whenever the name of a horizontal control point is modified in
this manner in the HZTL OBS data set for the purpose of making it
unique within the respective job, the appended information becomes
part of the station name, and care must be taken that exactly the
same information is appended to the station name in the heading of
the description and of all subsequent recovery notes which are
given for that horizontal control point in the companion GEOD DESC
data set (see Chapter 3).     

When the lengthy name of a horizontal control point must be
contracted to 30
characters, the abbreviation and/or editing of the station name in
question
should be accomplished with due regard to the following:  First, a
40-character version of the same station name is required in the
GEOD DESC data set submitted concurrently with the HZTL OBS data
set (see INTRODUCTION).  This less drastically contracted version
of the station name will be used for publication purposes. 
Second, the names of reference and azimuth marks are normally
formed by appending the symbols RM 1, RM 2, ..., RM 13, etc., and
AZ MK (possibly AZ MK 2, AZ MK 3, etc.) to the station name of the
control point to which they belong.  For this reason, the name of
a horizontal control point which has peripheral reference marks
and/or azimuth mark(s) may have to be further contracted to 24
characters (and possibly less) in order to allow for the
respective reference and azimuth mark names to confirm to the 30-
character limit.

    Name or Designation of RM or AZ MK:  Reference marks and
azimuth marks are usually identified by standard disk markers
which display an arrow as the survey point symbol at their center;
the markers are set in such a way that the arrow points toward the
associated horizontal control point.  Two or more reference marks
are normally established in the immediate vicinity of a monumented
horizontal control point.  The purpose of the reference mark is to
act as a "pointer" to the related horizontal control point,
thereby aiding in its recovery, and to provide a means of
verifying whether or not the station monument has been disturbed. 
In addition to the reference marks, an azimuth mark may be
established at some distance to provide an azimuth reference point
which is visible from ground level.  Less frequently, more than
one azimuth mark is established for the same horizontal control
point. 

The originally established reference marks of a horizontal control
point are normally assigned sequential numbers, e.g., NO 1, NO 2,
etc.  Any subsequently established reference mark should be
assigned the next unused number in the sequence, even though one
or more of the previously established reference marks may have
been destroyed.  The standard practice is to stamp the name of the
horizontal control point to which a reference mark belongs above
the arrow which appears in the center of the respective disk
marker, the number of the reference mark (i.e., NO 1, NO 2, etc.)
immediately below the arrow, and the year in which the reference
mark was set farther below the arrow.  The same procedure is 

                                2-32
followed in the case of an azimuth mark, except that a number is
normally assigned and stamped on the respective disk marker only if
more than one azimuth mark is involved.

The name or designation of a reference mark (RM) or an azimuth mark
(AZ MK) entered on the *82* record must not exceed 30 characters in
length.  It should normally consist of the name of the horizontal
control point to which the RM or AZ MK belongs, with the symbol RM
1, RM 2, ..., RM 13, etc. appended for reference marks NO 1, NO 2,
..., NO 13, etc.  For azimuth marks, the symbol AZ MK is appended if
only one azimuth mark is involved, otherwise the symbol AZ MK 2, AZ
MK 3, etc. for azimuth marks NO 2, NO 3, etc.  In general, nothing
else should be added to the name of an RM or AZ MK, except when the
numbering system outlined in the preceding paragraph has not been
followed, with the result that two or more reference or azimuth
marks associated with a horizontal control point are referred to by
the same name.

Considering that the total length of an RM or AZ MK name must not
exceed 30 characters, the name of the horizontal control point to
which the RM 1, RM 2, etc., and/or AZ MK symbols are appended must
be limited to 24 characters, and may have to be further contracted
if a numeral must follow the AZ MK symbol and/or the "year mark set"
has to be added.  The name of the respective horizontal control
point must be taken as it appears on the corresponding *80* or *81*
record (see Station Name), except for possible further abbreviation
and/or editing which may be required.

The same general considerations apply to a reference or azimuth mark
which is being treated as a control point (i.e., which is not
regarded as a peripheral RM or AZ MK), whose 30-character name is to
be entered on the respective *80* or *81* record.  Occasionally, an
existing monumented survey point of another agency is used for a
reference mark or, more frequently, for an azimuth mark.  Such a
survey point must be treated as a control point, i.e., it must be
identified by an four-digit station serial number.  If it can be
positioned (or if its geodetic position is available from other
sources), submit a *80* or *81* record for a control point of this
kind; otherwise submit a *82* record to give its name or
designation.

   Name or Designation of Bench Mark:  A bench mark (BM) is a
   monumented (or
otherwise permanently marked) vertical control point whose height
above mean sea level (MSL) has been determined by differential
leveling.  Bench marks occur in a horizontal control survey project
if (1) a horizontal control point is also a BM in a line of
differential leveling connected to the national vertical control
network, (2) a spur level line connection exists between a
horizontal control point and a nearby BM, or (3) a BM is included as
a control point in the project for the purpose of extending vertical
control by trigonometric leveling (vertical angles).  All bench
marks in a project should be positioned, if possible.

The name or designation of a bench mark entered on the *80* or *82*
record must not exceed 30 characters in length.  It should be taken
as it appears in the heading of the bench mark description, which
normally is identical to or closely resembles the name or
designation stamped on the disk.  If the name or designation of a
bench mark must be contracted in order to conform to the 30-
character limit, the same general considerations apply as for the
abbreviation and/or editing of the name of a horizontal control
point (see Station Name above).

If a reference mark disk (RM) for one control station is
subsequently used as an azimuth mark for another control station,
the name or designation of the mark should reflect the stamping on
the mark (original use and not subsequent use).

                                2-33
Likewise, if a bench mark disk (BM) is used as a reference mark for
a control station, the name or designation of the mark should always
be that of the bench mark.
 
    Geodetic Position:  The geodetic position of every horizontal
control point for which a *80* or *81* record is submitted must be
given to serve either as a fixed position or as a preliminary
position in the adjustment of the respective horizontal control
survey project.  The geodetic position may be expressed either in
terms of geographic coordinates (latitude and longitude) on the *80*
record, or it may be expressed in one of two plane coordinate
systems - the Universal Transverse Mercator (UTM) coordinates, or
the State Plane Coordinates (SPC) - on the *81* record.

For previously established horizontal control points which are
identified as "fixed" by means of a *90* record (see FIXED CONTROL
DATA RECORDS), the geodetic position given on the *80* or *81*
record should be either the published position, if the control point
in question is an existing point of the national horizontal control
network, or else a position obtained from a constrained adjustment.
                       
The *80* record is intended for horizontal control points whose
geodetic position is given in terms of geographic coordinates, i.e.,
as Latitude and Longitude.  In addition to the numeric value (in
sexagesimal degrees, minutes, seconds, and decimals of a second),
the Direction of Latitude must be specified as "N" or "S", and the
Direction of Longitude must be specified as "E" or "W", by a one-
letter code adjacent to the latitude and longitude fields.

The *81* record is intended for horizontal control points whose
geodetic position is given in terms of plane coordinates, i.e., as a
Y-Coordinate 
(northing) and an X-Coordinate (easting), followed by a four-digit
coordinate system zone designation.  If Universal Transverse
Mercator (UTM) coordinates are used, the northing and easting values
are expected in meters and decimals of a meter.  The zone
designation must be the appropriate UTM Zone Number (0001-0060) as
shown in ANNEX H.  If State Plane Coordinates (SPC) are used, the
northing and easting values are expected in meters and decimals of a
meter.  The zone designation must be the appropriate State Zone Code
as given in ANNEX B.

    Elevation and Elevation Code:  Elevation is the vertical
distance above the geoid - an equipotential surface.  Along the sea
coast the geoid closely follows mean sea level (MSL).  Often
referred to as "orthometric height," elevation is normally the
dominant component of ellipsoidal height.  Ellipsoidal height is the
sum of elevation and geoid height.  Geoid height is the name given
to the vertical separation between the geoid and the reference
ellipsoid of the geodetic datum used (NAD 83 or as specified on the
*13* record).  Ellipsoid heights of horizontal control points must
be known or closely approximated for the purpose of reducing
distance measurements to the reference ellipsoid and for computation
of the skew normal and deflection corrections which are applied to
horizontal directions and/or horizontal angles.

The elevation of every horizontal control point for which a *80* or
*81* record 
is submitted must be given, except for unaccessible, unmonumented,
recoverable landmarks positioned by intersection.  When given, the
elevation of such a 
landmark should be the ground level elevation (e.g., obtained from a
topographic map, if a more accurate value is not available), and the
height of the point actually sighted entered as the height of target
on the respective observation record.  But, since no distances are
involved, the elevation field of an unaccessible landmark is
preferred left blank.

                                 2-34
The elevation of a survey point is determined most accurately by
differential leveling.  Other less accurate methods of determining
the elevation of a survey point are (1) GPS observations, (2)
trigonometric leveling using reciprocal vertical angles, (3)
trigonometric leveling using non-reciprocal (i.e., one-sided)
vertical angles, and (4) photogrammetric methods.  In addition, an
estimate of elevation based on the exponential decrease of
atmospheric pressure with altitude can be obtained by a barometric
leveling scheme (e.g., with the aid of an altimeter).  As a last
resort, if elevation from another source is not at hand, the
approximate elevation can be obtained by interpolation between
adjacent elevation contour lines on a map.  In situations where
ellipsoidal heights are known, the orthometric height can be
computed by subtracting some estimate of the geoid height from the
ellipsoidal height.  Orthometric heights derived in this manner
are coded using the "G" code.  The geoid height value used in the
computation must be submitted on a *86* record.

In every case, the source and general accuracy of the elevation
value given on a *80*, *81*, or the preferred new *86* record must
be indicated by a one-letter Orthometric Height (OHT) Code (See
table on page 2-84 for explanations).  The possible elevation
codes are as follows:

       A - The control point is a bench mark (BM) in the NGSIDB.
       B - BM determined using FGCS/NGS procedures but not in the
       NGSIDB.
       C - The control point is a 'posted' bench mark.
       H - OHT determined using FGCS procedures but tied to only
   one (1) BM.
       L - OHT established using NGS leveling RESET procedures.
       F - OHT established using fly-leveling.
       T - OHT determined by leveling between control points which
       are not BMs.
       R - OHT determined by reciprocal vertical angles.
       V - OHT determined by non-reciprocal vertical angles.
       P - OHT determined by a photogrammetric method.
       M - OHT scaled from a topographic map.
       G - OHT determined from an ellipsoidal height.
       D - OHT determined by datum transformation.

   Station Order and Type:  A two-character field is reserved on
   the *80* and
*81* records for the order-and-type code.  The purpose of this
code is to
characterize the specific order of accuracy of the horizontal
control point and to indicate whether the horizontal control point
in question is monumented (or otherwise permanently marked),
unmonumented but recoverable (e.g., a landmark), or unmonumented
and non-recoverable (e.g., an auxiliary point). In addition, the
purpose of this code is to characterize the type of the survey
scheme of which the horizontal control point is a part and/or by
means of which it is positioned (i.e., triangulation,
trilateration, traverse, intersection, or resection).  It also
indicates whether the horizontal control point in question is
considered to be a main-scheme station or a supplemental station
in the respective survey scheme.

In every case, care must be taken to assign an order-and-type code
which reflects how the horizontal control point was used in the
project.  For example, if a horizontal control point previously
established as a first-order triangulation station is occupied in
the course of a second-order traverse project, then it must be
assigned an order-and-type code which classifies it as 
a second-order traverse station rather than as a first-order
triangulation station.  For control points which cannot be
positioned within the project


                                2-35
because of insufficient observations (but for which an accurate
geodetic position is available from other sources, and hence for
which a *80* or *81* record is submitted), the order-and-type code
is to be left blank.

The first character (order) of the order-and-type code indicates
the order of accuracy used to survey the main-scheme network.  It
reflects the surveying method used, procedures followed, and
specifications enforced by the project instructions.  It is also
intended to indicate whether the horizontal control point is a
monumented (or otherwise permanently marked) control point, an
unmonumented recoverable landmark, or a temporary point, not
permanently marked and therefore nonrecoverable, which must be
treated as a control point (e.g., an unmarked eccentric point
which is offset more than 10 meters from the respective control
point).  The respective "order codes" are as follows:

   1.  Order Codes of Permanently Marked Stations:

        A - Order A Interferometric Positioning
        B - Order B Interferometric Positioning
       0 - Trans-Continental Traverse (TCT)
       1 - First-Order Survey Scheme
       2 - Second-Order (Class I and Class II) Survey Scheme
       3 - Third-Order (Class I and Class II) Survey Scheme
       4 - Lower-Than-Third-Order Survey Scheme and
           Supplemental Unmonumented Recoverable Landmarks (see
below).

   2.  Order Codes of Nonrecoverable Points:

       5 - First-Order Survey Scheme
       6 - Second-Order (Class I and Class II) Survey Scheme
       7 - Third-Order (Class I and Class II) Survey Scheme
       8 - Lower-Than-Third-Order Survey Scheme

In general, the order-and-type codes of all monumented (or
otherwise permanently marked) horizontal control points should be
assigned the same order code (equal to the order code of the
order-and-class code assigned to the project - see under PROJECT
DATA RECORDS), except when survey work of more than one order-and-
class category is included in the project.  In this case, special
care must be taken to assign the appropriate order code to every
monumented control point according to the order-and-class category
of the respective section of the project; control points which
qualify for more than one order designation must be assigned the
order code which corresponds to the higher order-and-class
category.  But, in a Trans-Continental Traverse (TCT) type
project, only the stations of the high-precision traverse proper
(i.e., stations connected by horizontal directions and by
distances measured with electro-optical DME on two nights) should
carry the order code "0"; other horizontal control points occupied
and/or sighted upon should be treated as comparable stations in a
first-order project.                                               
                                                            
As a matter of convention, the order code "4" is assigned to
unmonumented recoverable landmarks positioned as supplemental
stations, i.e., as intersections or spur traverse stations which
are incidental to the primary survey scheme, regardless of the
order-and-class category of the project or section of project of
which they are a part.  However, if such a landmark (e.g., a
flagpole or church spire) occurs as an unoccupied main-scheme
station in a triangulation network, then it must be assigned the
same order code as any other 
                                2-36
main-scheme station in its vicinity, i.e., a main-scheme
intersection station which is an unmonumented recoverable landmark
must be assigned the same order code as a monumented control
point.

Considering the discussion in the preceding two paragraphs, the
allowable order codes of the order-and-type codes assigned to
horizontal control points within a project (or within a section of
a project) are as follows:

                  TABLE 2-5 - ALLOWABLE ORDER CODES     
           Ŀ
           SURVEY SCHEME                    ALLOWABLE 
           ORDER-AND-CLASS CATEGORY          ORDER CODES 
           Ĵ
           Interferometric Positioning           A,B     
           Trans-Continental Traverse (TCT)    0,1,4,5   
           First-Order                           1,4,5   
           Second-Order (Class I and Class II)   2,4,6   
           Third-Order (Class I and Class II)    3,4,7   
           Lower-Than-Third-Order                  4,8   
           

The second character (type) of the order-and-type code indicates
the type of survey used to position the horizontal control point. 
It is also intended to indicate whether the horizontal control
point is a main scheme station (i.e., one which is essential to
the primary survey scheme) or a supplemental station   (i.e., one
which is incidental to the primary survey scheme).  The respective
"type codes" are as follows:


   1.  Type Codes of Main-Scheme Stations:

       1 - Positioned Primarily by Triangulation
       2 - Positioned Primarily by Trilateration
       3 - Positioned Primarily by Traverse
       A - Positioned Primarily by Interferometric Satellite
       Relative               Positioning

   2.  Type Codes of Supplemental Stations:

       4 - Positioned Primarily by Triangulation
       5 - Positioned Primarily by Trilateration            
       6 - Positioned Primarily by Traverse
       7 - Positioned by Intersection (Note:  1 if Main-Scheme
       Station)
       8 - Positioned by Resection
       B - Positioned Primarily by Interferometric Satellite
       Relative               Positioning


As mentioned before, an intersection station which occurs as a
main-scheme station (essential to the primary survey scheme) in a
triangulation network is assigned the type code "1".

If it is not clear whether a horizontal control point is a main-
scheme or
supplemental station in a lst-Order or 2nd-Order (Class I or Class
II) network, it should be treated as a main-scheme station.  In
particular, if special effort 
                                2-37
has been made to preserve the nominal accuracy of the respective
main-scheme network in the positioning of a station which may not
appear to be essential to the primary survey scheme (e.g., extra
angular observations were taken and/or a distance was measured
with electro-optical DME), such a supplemental station should be
regarded as a main-scheme station and assigned a type code
accordingly.

In a third-order and lower-than-third-order survey schemes, the
distinction between main-scheme and supplemental stations is
unimportant, hence type codes 4, 5, and 6 are not used with order
codes 3 and 4; however, type codes 7 and 8 are still used to
identify supplemental intersection and resection stations.  In
particular, the order-and-type code assigned to a recoverable
landmark which is incidental to the survey scheme should be 47 if
positioned by intersection (43 if positioned by a spur traverse)
in a survey scheme of any order and class.  Considering the
discussion above, the allowable combinations of order and type
codes that can be assigned to horizontal control points within a
project (or within a section of a project) are as follows:

 
                 TABLE 2-6 - ALLOWABLE TYPE CODES 
            
                Ŀ 
                 ORDER               ALLOWABLE      
                 CODE                TYPE CODES     
              Ĵ
                   A                    A            
                   B                    A,B          
                  0                     3,6          
                  1,5          1,2,3,4,5,6,7,8,A,B   
                  2,6        1,2,3,4,5,6,7,8,A,B   
                  3,7             1,2,3,7,8,A    
                  4,8                1,2,3,7,8,A    
              


Whenever a horizontal control point qualifies for more than one
type code (i.e., when a station can be considered to be positioned
by two or more different survey methods), the type code which
reflects the survey method resulting in the strongest position,
when used alone, should be assigned.  A hierarchy of order-and-
type codes is given in ANNEX E.

   Geoid Height:  Geoid height is the name given to the vertical
   separation
between the geoid and the reference ellipsoid of the geodetic
datum used (NAD 83 or as specified on the *13* record).  Along the
sea coast the geoid, an equipotential surface, closely follows
mean sea level (MSL).  Elevation is the vertical distance above
the geoid.  Often referred to as "orthometric height," elevation
is normally the dominant component of ellipsoidal height. 
Ellipsoidal height is the sum of elevation and geoid height. 
Ellipsoidal height must be known for every horizontal (and
vertical) control point for the purpose of reducing horizontal
control survey observations to the reference ellipsoid (and for
the extension of vertical control by trigonometric leveling). 
Since the 
geoid height value associated with a horizontal (or vertical)
control point is often unknown, it is a common practice to assume
it to be zero, and hence to use the elevation as the best
available approximation for the desired ellipsoidal height.

                               2-38
If a reliable value of geoid height is known, a *86* record should
be submitted on which the respective geoid height is given in
meters and decimals of meter.  Note that the geoid height is
positive when the geoid is above the ellipsoid and that it is
negative when the geoid is below the ellipsoid.  The geoid height
value given should be accompanied by an estimate of its absolute
accuracy in the form of a standard error (Sigma).

     Deflection of Vertical:  The deflection of vertical is the
angle formed by the tangent to the direction of gravity (known as
the "vertical") and the "normal" to the reference ellipsoid of the
geodetic datum (NAD 83 or as specified on the *13* record).  In
addition to the magnitude of this angle, usually given in seconds
and decimals of second of arc, the direction (e.g. the geodetic
azimuth) of the deflection must also be specified.  Alternatively,
the direction of the deflection of vertical is implied when the
deflection is given in terms of two rectangular components - e.g.
the north-south or meridional component and the east-west or
prime-vertical component.

The deflection of vertical comes into consideration in connection
with horizontal directions, horizontal angles, and vertical angles
observed with theodolites or transits which are leveled (i.e.,
oriented with respect to the direction of gravity).  Accordingly,
the deflection of vertical must be known at every point from which
horizontal directions, horizontal angles, or vertical angles have
been observed, so that appropriate corrections can be computed to
convert these observed quantities from the gravity-oriented
"astronomic" frame of reference to the ellipsoid-oriented geodetic
system.

Because the deflection of vertical at a given horizontal control
point is often unknown, it is a common practice to assume it to be
zero.  Since, in the continental United States, the maximum
deflection of vertical, defined with respect to the North American
1983 datum (NAD 83), seldom exceeds 20 seconds of arc, and is
normally much less (e.g., 3 to 5 seconds), the error introduced by
this approximation in connection with the reduction of horizontal
directions and horizontal angles is imperceptible except for long,
inclined lines of sight in mountainous regions.  However, in
connection with the use of vertical angles for determining
elevation differences, this approximation is one of the major
sources of error which render the extension of vertical control by
trigonometric leveling inaccurate.

If the deflection of vertical is reliably known (e.g., as a result
of astronomic latitude and longitude observations), a *85* record
should be submitted.  The deflection is given in terms of the
respective meridional (i.e., north-south) and prime-vertical
(i.e., east-west) components, each expressed in seconds and
decimals of second of arc.

The Meridional Component (Xi) of the deflection of vertical is the
difference between the astronomic and geodetic latitudes of the
horizontal control point.  The direction of the meridional
component, i.e., the Direction of Xi must be specified as "N" or
"S" according to whether the astronomic latitude falls north or
south of the corresponding geodetic latitude.  The Prime-Vertical
Component (Eta) of the deflection of vertical is the difference
between the astronomic and geodetic longitudes of the horizontal
control point, multiplied by the cosine of the approximate
(astronomic or geodetic) latitude.  The direction of the prime-
vertical component, i.e., the Direction of Eta must be specified
as "E" or "W" according to whether the astronomic longitude falls
east or west of the corresponding geodetic longitude.  Both the
meridional and prime-vertical components 

                                2-39
of the deflection of vertical should be accompanied by an estimate
of their absolute accuracy in the form of a standard error
(Sigma).

The results of astronomic azimuth observations and astronomic
position observations (recorded as the meridional and prime-
vertical components of the deflection of vertical) are entered on
the *60* and *85* records of the HZTL OBS data set.  In addition,
all astronomic latitude, longitude, and/or azimuth observations
should be submitted separately in full detail for rigorous
processing and incorporation into the astronomic data file of the
National Geodetic Survey Data Base.


FIXED CONTROL DATA RECORDS

          *90* - Fixed Control Record

The purpose of the *90* record is to allow identification of hori-
zontal control points which are to be used as "fixed control" in
the project, i.e., those control points whose coordinates are to
be held fixed in the adjustment of the respective horizontal
control network.  Submit a *90* record for each horizontal control
point to be held fixed; a *80* or *81* record must appear among
the *80*-series records (see SURVEY POINT DATA RECORDS) for each
horizontal control point identified as "fixed" by a *90* record. 
And, as stated previously, the geodetic position given on each of
these *80* or *81* records should be either the published
position, if the control point in question is an existing point of
the national horizontal control network, or else a position
obtained from a constrained adjustment.

Normally, at least two horizontal control points will be
designated as fixed control in a horizontal control survey
project.  If only one horizontal control point is identified, the
necessary scale and orientation of the horizontal control network
must be provided by sufficient *50*-series and *60*-series records
(see DISTANCE DATA RECORDS and AZIMUTH DATA RECORDS).























                                2-40
RECORD FORMATS

For each record which may appear in an HZTL OBS data set (see
Table 2-1), a block diagram has been prepared to illustrate the
respective format.  These "format diagrams" have been designed to
fulfill the following objectives:

   1.  Each record is 80 characters long (standard punched card
image).

    2.  Each record has a fixed format, i.e., every data field has
a
       specific length and specific position within the record.

   3.  Each format diagram is a graphical image of the respective
   record.

   4.  Within the limits of available space, the data to be
   entered in
       each data field are identified on the format diagrams to
       render
       them self-explanatory.  See pages 2-88 thru 2-109.

    5.  In addition, a brief information and instruction sheet
accompanies
       each format diagram.  See pages 2-41 thru 2-87.              
                  
                               

    Required Data:  In general, only those records which represent
actual field observations collected during the survey project
should be included in an HZTL OBS data set (e.g., no *60* records
should be submitted if no astronomic/Laplace azimuths were
determined in the project).  Records that are optional or those
which may be omitted under certain circumstances are clearly
designated on the instruction sheet for each format diagram.  The
required data fields on the format diagrams have been highlighted
(bold printed).



























                                2-41
DATA SET IDENTIFICATION RECORD (*aa*)                              
             

The first record in a Horizontal Observation Data set must be a
Data Set
Identification Record which identifies the data class and type
(HTZL OBS), the name of the submitting organization, and date the
data set was created.  The job code is a two-character
alphanumeric code assigned to each horizontal control job
submitted by an organization.  An asterisk (*) immediately
precedes and follows the code and the first character of the code
must be a letter.  Assign the code A1 to the first job and
continue in sequence to the last.  (A1, A2...,  A9, B1,
B2,...etc.)  The job code used in this record must be identical to
the job code in the Data Set Termination Record, the last record
in the Horizontal Observation Data Set (HZTL  OBS), and identical
to the job code used in both the Data Set Identification Record
and the Data Set Termination Record of the  Geodetic Control Point
Descriptive Data Set (GEOD DESC).  This record is required.       


                                  *aa* FORMAT


    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED. MUST BE 000010.   
                 CC 07-10  JOB CODE.  MUST BE *aa*.  THE SYMBOL
"aa"  DENOTES THE TWO-                      CHARACTER CODE
ASSIGNED BY THE SUBMITTING ORGANIZATION.
    CC 11-14  DATA CLASSIFICATION.  MUST BE HZTL.
    CC 15-18  DATA TYPE.  MUST BE OBS.  LEFT JUSTIFIED.
    CC 19-24  ABBREVIATION OF ORGANIZATION.  SEE ANNEX C.  IF NOT
LISTED THERE,                PROPOSED ABBREVIATION MUST BE
ACCEPTED BY NGS PRIOR TO FIRST                     SUBMITTAL OF
DATA. SEE ANNEX K.
    CC 25-66  SUBMITTING ORGANIZATION.  FULL NAME OR ORGANIZATION
PERFORMING THE                OBSERVATION.  LEFT JUSTIFIED.
    CC 67-72  ASSIGNED G/GPS NUMBER.  (FOR NGS USE ONLY)
    CC 73-80  DATE DATA SET CREATED.  YEAR, MONTH, DAY (YYYYMMDD).

For a more detailed explanation of the contents of the record see
Chapter 1, page 1-1, JOB CODE AND POINT NUMBERING and Chapter 2,
pages 2-1 thru 2-3, HZTL OBS DATA SET RECORDS.

















                                2-42
                    PROJECT TITLE RECORD (*10*)
                                                                   
             This record identifies the project by name.  The use
of geographic locality alone as the title of a horizontal control
survey project has traditionally been the practice of NGS and its
predecessors.  This record is required.

                            *10* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED. MUST BE 000020.
    CC 07-10  DATA CODE.  MUST BE *10*.
    CC 11-80  PROJECT TITLE.  LEFT JUSTIFIED.

              PROJECT TITLE CONTINUATION RECORD (*11*)
                                                                   
             This record is required only if the project title in
the *10* record exceeds the 70-character field allowed.  Do not
divide words between *10* and *11* records.  This record is
optional.

                            *11* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *11*.
    CC 11-80  PROJECT TITLE CONTINUED FROM *10* RECORD, IF
NECESSARY.  THIS                    RECORD IS OPTIONAL.

For a more detailed explanation of the contents of this record see
Chapter 2, pages 2-5 and 2-6, PROJECT DATA RECORDS.

























                                2-43
PROJECT INFORMATION RECORD (*12*)                                  
         
This record identifies the person responsible for the survey
(chief of party) by name, provides a record of the dates on which
survey operations commenced and terminated, indicates type of
survey, and order and class of survey.  This record is required.  


                                *12* FORMAT

    CC 01-06  SEQUENCE NUMBER. RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                      PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *12*.
    CC 11-16  DATE FIELD OPERATIONS BEGAN.  YEAR, MONTH  (YYYYMM).
    CC 17-22  DATE FIELD OPERATIONS ENDED.  YEAR, MONTH  (YYYYMM).
    CC 23-25  CHIEF OF PARTY INITIALS.  (FIRST C.O.P.).        
    CC 26-43  SURNAME AND INITIALS OF CHIEF OF PARTY (FIRST
C.O.P.) LEFT                       JUSTIFIED.  SEPARATE SURNAME
AND EACH INITIAL WITH A BLANK.  DO                  NOT USE
PERIODS OR OTHER SPECIAL CHARACTERS.
    CC 44-46  CHIEF OF PARTY INITIALS.  (SECOND C.O.P., IF ANY).
    CC 47-64  SURNAME AND INITIALS OF SECOND CHIEF OF PARTY, IF
ANY.
    CC 65-75  BLANK
    CC 76     SURVEY METHOD. IDENTIFY PRIMARY SURVEY METHOD USED.
SEE TABLE                    BELOW.
    CC 77-78  PRIMARY STATE OR COUNTRY CODE.  SEE ANNEX A.        
    CC 79-80  ORDER AND CLASS OF SURVEY.  SEE TABLE BELOW.

    Survey Method Codes              Order and Class of Survey
                                     Codes

    1 - Triangulation                AA - AA Order Interferometric
                                     Positioning
    2 - Trilateration                A0 - A Order Interferometric
                                     Positioning
    3 - Traverse                     B0 - B Order Interferometric
                                     Positioning
    4 - Global Positioning System         00 - Trans-Continental
                                          Traverse
                                 10 - First Order
                                 21 - Second Order Class I
                                 22 - Second Order Class II
                                 31 - Third Order Class I
                                 32 - Third Order Class II
                                 40 - Lower Than Third Order



For a more detailed explanation of the contents of this  record see
Chapter 2, pages 2-5 thru 2-7, PROJECT DATA RECORDS and DATE AND
TIME.








                                  
                                      2-44                          
            GEODETIC DATUM AND ELLIPSOID RECORD (*13*)

This record defines the datum and reference ellipsoid for the
geodetic positions, deflections of the vertical, geoid heights,
and/or reduced ellipsoidal distances (Code E in *52* record) as
they appear in this project.  Do not enter the Inverse Flattening
(1/f) if the ellipsoid is defined by the  Semi-Major Axis (a) and
the Semi-Minor Axis (b).  Likewise, do not enter the Semi-Minor
Axis (b) if the ellipsoid is defined by (a) and (1/f).  This
record is required unless the datum is the North American 1983
(NAD 83).

                                *13* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD. 
    CC 07-10  DATA CODE.  MUST BE *13*.
    CC 11-34  DATUM NAME.  DO NOT INCLUDE THE WORD 'DATUM' IN  THE
NAME.                       ABBREVIATE IF NECESSARY.   
    CC 35-50  NAME OF THE ELLIPSOID.
    CC 51-60  SEMI-MAJOR AXIS (a) IN METERS (MMMMMMMmmm).
    CC 61-70  INVERSE FLATTENING (1/f) (XXXxxxxxxx).
              THE FLATTENING (f) = (a - b) / a.
    CC 71-80  SEMI-MINOR AXIS (b) IN METERS (MMMMMMMmmm).































                                2-45
              HORIZONTAL DIRECTION SET RECORD (*20*)

This record identifies the initial direction for each set of
direction observations.  Use the Horizontal Direction Record
(*22*) for all the remaining directions observed in the same set. 
The instrument station (standpoint) refers to the point from which
the observation is taken (e.g., the point occupied by the
observer).  The target station (forepoint) refers to the point to
which the observation is directed.  Use the *21* Comment Record(s)
immediately following the *20* record for any comments.  

To anticipate the accuracy of an observation, the type of survey
equipment used must be known.  To identify the instrument used for
each observation, assign a unique three-digit number (Job-Specific
Instrument Number) in the range 001 to 999 to each item of survey
equipment used in the job.  Each number will cross reference a NGS
survey equipment code in the *70* record.  See Chapter 2, page
2-10, Job-Specific Instrument Number and page 2-28, Survey
Equipment Data Records.

                                *20* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
INCREMENT OF 10                   FROM PREVIOUS RECORD. 
    CC 07-10  DATA CODE.  MUST BE *20*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).                   FOR ADDITIONAL INFORMATION SEE
CHAPTER 1, PAGES 1-1 THRU 1-3, JOB                CODE AND SURVEY
POINT NUMBERING; CHAPTER 2, PAGES 2-8 THRU 2-9,                 
OBSERVATION DATA RECORDS; PAGES 2-12 THRU 2-13, ASSIGNMENT OF      
             STATION SERIAL NUMBERS; AND PAGE 2-14, TREATMENT OF
ECCENTRIC                    OBSERVATIONS.
    CC 15-16  SET NUMBER.  ENTER 01 FOR THE FIRST SET OF THE
DIRECTION                         OBSERVATIONS.  USE 02, 03, ETC.
FOR SUCCESSIVE SETS.  SEE CHAPTER                2, PAGE 2-18, SET
NUMBER.
    CC 17-22  FIELD RECORD BOOK NUMBER.  VOLUME NUMBER ASSIGNED TO
THE FIELD                   BOOK IN WHICH THE DIRECTION
OBSERVATIONS ARE RECORDED.
    CC 23-24  NUMBER OF OBJECTS SIGHTED IN THIS SET.  THIS VALUE
EQUALS THE SUM                OF THE *20* RECORD AND THE *22*
RECORD(S) IN THIS SET.  SEE                      CHAPTER 2, PAGE
2-18.
    CC 25-29  WEATHER CODE.  THE FIRST COLUMN OF THIS CODE (25) IS
A PROBLEM                   INDICATOR FOLLOWED BY VISIBILITY,
TEMPERATURE, CLOUD COVER AND                   WIND INDICATORS IN
SUCCESSION.  FOR INFORMATION CONCERNING THE 
              WEATHER CODE TO BE USED IN CONNECTION WITH
HORIZONTAL                            OBSERVATIONS, SEE CHAPTER 2,
PAGES 2-10. 
    CC 30-32  INITIALS OF THE OBSERVER.
    CC 33-35  JOB-SPECIFIC INSTRUMENT NUMBER (JSIN).  THE UNIQUE
THREE-DIGIT                   NUMBER IN THE RANGE 001 TO 999
ASSIGNED TO THE INSTRUMENT USED TO                OBTAIN THIS
OBSERVATION.  THIS NUMBER WILL CROSS REFERENCE THE NGS             
  SURVEY EQUIPMENT CODE IN THE *70* RECORD.  






                                2-46
    CC 36-39  HEIGHT OF INSTRUMENT.  ENTER THE VERTICAL DISTANCE
FROM THE TOP OF                THE OCCUPIED SURVEY MARK (POINT) TO
THE OPTICAL CENTER OF THE                    SURVEYING INSTRUMENT. 
IN METERS (MMmm).  FOR ADDITIONAL 
              INFORMATION SEE CHAPTER 2, PAGE 2-11, HEIGHT OF
INSTRUMENT AND                   HEIGHT OF TARGET.
    CC 40-45  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD). 
SEE CHAPTER 2,                 PAGES 2-18, DATE AND TIME. 
    CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE CHAPTER 2,
PAGE 2-7,                    TIME, AND PAGE 2-18, DATE AND TIME.
    CC 50     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H       
                           WHICH REPRESENTS THE TIME ZONE
OCCUPIED.  SEE  CHAPTER 2, PAGE                   2-7, TIME ZONE.
    CC 51-54  STATION SERIAL NUMBER.  TARGET STATION.  SEE CHAPTER
1, PAGES 1-1                THRU 1-3, JOB CODE AND SURVEY POINT
NUMBERING; CHAPTER 2, PAGES                  2-8 THRU 2-9,
OBSERVATION DATA RECORDS; PAGES 2-12 THRU 2-13,                   
ASSIGNMENT OF STATION SERIAL NUMBERS; AND PAGE 2-14, TREATMENT OF  
             ECCENTRIC OBSERVATIONS.
    CC-55-58  HEIGHT OF TARGET.  ENTER THE VERTICAL DISTANCE FROM
THE TOP OF THE                TARGET STATION SURVEY MARK (POINT)
TO THE TARGET (POINT) ABOVE THE                MARK USED FOR THE
DIRECTION OBSERVATIONS.  IN METERS (MMmm).  SEE               
CHAPTER 2, PAGE 2-11, HEIGHT OF INSTRUMENT AND HEIGHT OF TARGET.
    CC-59     VISIBILITY CODE.  SEE CHAPTER 2, PAGE 2-11,
VISIBILITY CODE. 
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF POINTINGS OR
MEASUREMENTS USED                TO DETERMINE A HORIZONTAL
DIRECTION.  SEE CHAPTER 2, PAGE 2-16,                  NUMBER OF
REPLICATIONS AND PAGE 2-19, LAST PARAGRAPH.
    CC 62-63  REJECTION LIMIT.  THE MAXIMUM ALLOWED DEVIATION OF A
SINGLE                      OBSERVATION FROM THE MEAN OF ALL THE
OBSERVATIONS USED TO                        DETERMINE A DIRECTION
IN A SET.  IN SECONDS. SEE CHAPTER 2, PAGE                 2-16,
REJECTION LIMIT.
    CC-64-72  INITIAL DIRECTION.  MEAN OF POINTINGS OR
MEASUREMENTS TO THE FIRST                OBJECT SIGHTED IN THE
OBSERVING SEQUENCE, NORMALLY ASSIGNED A                    VALUE
ZERO DEGREES, ZERO MINUTES AND ZERO SECONDS (DDDMMSSss).           
       SEE CHAPTER 2, PAGES 2-17 AND 2-18, HORIZONTAL DIRECTION
DATA                    RECORDS.
    CC 73-76  INTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss).
ENTER ONLY IF                    RELIABLE ESTIMATES ARE AVAILABLE. 
 SEE CHAPTER 2, PAGE 2-17,                    INTERNAL CONSISTENCY
SIGMA.
    CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss).
ENTER ONLY IF                    RELIABLE ESTIMATES ARE AVAILABLE. 
 SEE CHAPTER 2, PAGE 2-17,                    EXTERNAL CONSISTENCY
SIGMA.
          
For a more detailed discussion on accuracy, internal and external
errors, see Chapter 2, pages 2-15 thru 2-17, ACCURACY OF THE
OBSERVATIONS. 










                                2-47
            HORIZONTAL DIRECTION COMMENT RECORD  (*21*)

Use this record for comments pertinent to the set of directions. 
This record is required to explain the problem encountered, if the
problem indicator (Column 25) on the respective Horizontal
Direction Set Record (*20*) is 1.  Otherwise, this record is
optional.

                                *21* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM PREVIOUS            RECORD.
   CC 07-10  DATA CODE.  MUST BE *21*.
   CC 11-80  COMMENT.  IF THE COMMENT(S) EXCEED 70 CHARACTERS, USE
   ANOTHER *21*            RECORD FOR CONTINUATION.  ANY NUMBER OF
   *21* RECORDS IS ALLOWED.            BUT, DO NOT DIVIDE WORDS
   BETWEEN CONSECUTIVE *21* RECORDS.  SEE           CHAPTER 2,
   PAGES 2-17 AND 2-18, HORIZONTAL DIRECTION DATA RECORDS.





































                                2-48
                HORIZONTAL DIRECTION RECORD (*22*)

Use this record for the second and subsequent directions observed
in the same horizontal direction set.  Use the Horizontal
Direction Set Record (*20*) for the first direction (initial)
observed in the set.

                            *22* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM PREVIOUS            RECORD.
   CC 07-10  DATA CODE.  MUST BE *22*.
   CC 11-14  STATION SERIAL NUMBER.  INSTRUMENT STATION
   (STANDPOINT).  MUST BE          IDENTICAL TO THE STATION SERIAL
   NUMBER (SSN) IN CC 11-14 ON THE           RESPECTIVE *20*
   RECORD. 
   CC 15-16  SET NUMBER.  MUST BE IDENTICAL TO THE SET NUMBER IN
   THE PRECEDING            *20* RECORD.
   CC 17-45  BLANK
   CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGE 2-7
   THRU 2-8, TIME.
   CC 50     TIME ZONE.  ENTER LETTER CODE FROM ANNEX H.  SEE PAGE
   2-7, TIME             ZONE.
   CC 51-54  STATION SERIAL NUMBER (SSN).  TARGET STATION
   (FOREPOINT).  FOR            ADDITIONAL INFORMATION SEE
                              CHAPTER 1, PAGES 1-1 THRU 1-3, JOB
                              CODE   AND SURVEY POINT NUMBERING; 
                              CHAPTER 2, PAGES 2-8 THRU 2-9,       
                                OBSERVATION DATA RECORDS;  PAGES
                              2-12 THRU 2-13, ASSIGNMENT OF      
                              STATION SERIAL NUMBERS; AND PAGE
                              2-14, TREATMENT OF ECCENTRIC       
                              OBSERVATIONS.
   CC 55-58  HEIGHT OF TARGET.  ENTER VERTICAL DISTANCE FROM THE
   TOP OF THE              TARGET STATION SURVEY MARK (POINT) TO
   THE TARGET (POINT) ABOVE THE            MARK, USED FOR THE
   DIRECTION OBSERVATIONS.  IN METERS (MMmm).  SEE           
   CHAPTER 2, PAGE 2-11, HEIGHT OF INSTRUMENT AND HEIGHT OF
   TARGET.
   CC 59     VISIBILITY CODE.  SEE PAGE 2-11, VISIBILITY CODE.
   CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF POINTINGS OR
   MEASUREMENTS TO             DETERMINE THIS OBSERVED DIRECTION. 
   SEE CHAPTER 2, PAGE 2-16,                NUMBER OF REPLICATIONS 
   AND PAGE 2-19, LAST PARAGRAPH.
   CC 62-63  REJECTION LIMIT.  MAXIMUM ALLOWED DEVIATION FROM THE
   MEAN.  IN              SECONDS.  SEE PAGE 2-16,  REJECTION
   LIMIT.
   CC 64-72  CLOCKWISE DIRECTION.  MEAN OF POINTINGS OR
   MEASUREMENTS TO EACH                OBJECT OBSERVED IN A SET. 
   IN DEGREES, MINUTES, SECONDS 
              (DDDMMSSss).
   CC 73-76  INTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss) SEE
   PAGE 2-17,               INTERNAL CONSISTENCY SIGMA.
   CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss)  SEE
   PAGE 2-17,              EXTERNAL CONSISTENCY SIGMA.










                                2-49
                GPS OCCUPATION HEADER RECORD (*25*)

This record is used to define session information and the raw data
file name at a station.  There must be an occupation header record
for each receiver in each session.  Use the Comment Record (*26*)
immediately following the *25* record for any comments.           


To anticipate the accuracy of an observation, the type of survey
equipment used must be known.  To identify the instrument employed
on each particular observation record in a concise manner, assign
a unique three-digit number (Job-Specific Instrument Number) in
the range 001 to 999 to each item of survey equipment used in the
job.  Each unique number will cross reference a NGS survey
equipment code in the *70* record.  See Chapter 2, page 2-10, Job-
Specific Instrument Number and page 2-28, Survey Equipment Data
Records.  This record is required.

                            *25* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
             INCREMENT OF 10 FROM PREVIOUS RECORD. 
   CC 07-10  DATA CODE.  MUST BE *25*.
   CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION. 
             FOR ADDITIONAL INFORMATION  SEE CHAPTER 1, PAGES 1-2
             THRU 1-6, JOB CODE AND SURVEY POINT NUMBERING;
             CHAPTER 2, PAGES 2-8 THRU 2-9, OBSERVATION DATA
             RECORDS; PAGES 2-12 THRU 2-14, ASSIGNMENT OF STATION
             SERIAL NUMBERS; AND PAGE 2-14, TREATMENT OF ECCENTRIC
             OBSERVATIONS.  
   CC 15-24  DATA MEDIA IDENTIFIER.  A CODE WHICH SPECIFICALLY
             DEFINES THE RECEIVER TYPE, DAY, YEAR, SESSION, AND
             STATION OBSERVED.  FOR USE IN THE B-FILE AND G-FILE. 
             SEE ANNEX L, PAGES L-1 AND L-2. THE FORMAT OF A DATA
             MEDIA IDENTIFIER IS:  ADDDYSNNNN, WHERE:
                A    IS THE CHARACTER WHICH INDICATES THE RECEIVER
                  MANUFACTURER:  A = ASHTECH, INC; C = TOPCON CORP;
                 D = DEL
                  NORTE TECHNOLOGY, INC; G = ALLEN OSBORNE
                 ASSOCIATES, INC;
                  I = ISTAC, INC; L =  MINI-MACTM; M = MacrometerR;
                  N = NORSTAR INSTRUMENTS, LTD; O =  MOTOROLA, INC;
                 R =
                  TRIMBLE NAVIGATION, LTD; S = SERCEL,  INC;  T =
                 TEXAS
                  INSTRUMENTS,INC; W = LEICA  HEERBRUGG AG-WILD
                 HEERBRUGG-
                  MAGNAVOX, INC; V = NOVATEL  COMMUNICATIONS, LTD;
                 X = OTHER
             DDD  IS THE DAY OF YEAR OF THE FIRST DATA EPOCH (UTC)
             Y    IS THE LAST DIGIT OF THE YEAR OF THE FIRST DATA
             EPOCH
             S    IS THE LETTER OR NUMBER OF THE SESSION OBSERVED
             NNNN IS THE PROJECT UNIQUE, FOUR (4)-CHARACTER
             ABBREVIATION OF
                  A STATION NAME. 
   CC 25-27    INITIALS OF THE OBSERVER
   CC 28-30    JOB-SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE-
   DIGIT NUMBER
             IN THE RANGE 001 TO 999 ASSIGNED TO THE INSTRUMENT
             USED TO OBTAIN THIS OBSERVATION.  THIS NUMBER WILL
             CROSS REFERENCE THE
             NGS SURVEY EQUIPMENT CODE IN THE *70* RECORD.
   CC 31-32  LENGTH OF THE CABLE USED TO CONNECT RECEIVER AND
             ANTENNA.        (XX) METERS
   CC 33-80  BLANK

                               2-50               GPS OCCUPATION COMMENT RECORD (*26*)

Use this record for comments pertinent to the GPS occupation
session.  This record is optional. 

                            *26* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
             INCREMENT OF 10 FROM PREVIOUS RECORD.  
   CC 07-10  DATA CODE.  MUST BE *26*.
   CC 11-80  COMMENT.  IF THE COMMENT(S) EXCEED 70 CHARACTERS, USE
             ANOTHER *26* RECORD FOR CONTINUATION.  ANY NUMBER OF
             *26* RECORDS IS ALLOWED, BUT, DO NOT DIVIDE WORDS
             BETWEEN CONSECUTIVE *26* RECORDS.






































                                2-51             GPS OCCUPATION MEASUREMENT RECORD (*27*)

To identify the station occupied on each particular observation
record in a concise manner, assign a unique four-digit number
(Station Serial Number) in the range 0001 to 9999 to each station
occupied in the job.  Each unique number will cross reference a
survey station in an *80* record.  See Chapter 1, page 1-1, Job
Code and Survey Point Numbering and Chapter 2, page 2-12,
Assignment of Station Serial Numbers.  Two Occupation Measurement
Records must be completed for each station in each session, i.e.
one pre-session and one post-session record.  This record is
required.

                            *27* FORMAT

  CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
            INCREMENT OF 10 FROM PREVIOUS RECORD. 
  CC 07-10  DATA CODE.  MUST BE *27*.
  CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION.  FOR
            ADDITIONAL INFORMATION SEE CHAPTER 1, PAGES 1-2 THRU
            1-6, JOB CODE AND SURVEY POINT NUMBERING; CHAPTER 2,
            PAGES 2-8 THRU 2-9, OBSERVATION DATA RECORDS; PAGES 2-
            12 THRU 2-13, ASSIGNMENT OF STATION SERIAL NUMBERS;
            AND PAGE 2-14, TREATMENT OF ECCENTRIC OBSERVATIONS.  
  CC 15-20  DATE OF OBSERVATION.(UTC)  YEAR, MONTH, DAY (YYMMDD). 
            SEE CHAPTER 2, PAGES 2-18, DATE AND TIME.   
  CC 21-24  TIME.  HOURS, MINUTES (HHMM)(UTC).  SEE CHAPTER 2,
            PAGE 2-7, TIME, AND PAGE 2-18, DATE AND TIME.
  CC 25-29  HEIGHT OF THE ANTENNA PHASE CENTER ABOVE THE MONUMENT
            (XX.xxx) IN METERS.
  CC 30-33  DRY BULB TEMPERATURE (XXX.x).  ALL REQUIRED WEATHER
            INFORMATION CAN BE FOUND ON THE METEOROLOGICAL DATA
            PORTION OF THE OBSERVER'S FIELD LOG.  IT IS IMPORTANT
            TO MAKE SURE YOU ARE ENTERING DATA FOR THE CORRECT
            SESSION (BEGINNING AND ENDING READINGS).
  CC 34         DRY BULB TEMPERATURE CODE (C/F).  THE TEMPERATURE
            GIVEN MUST BE        RECORDED IN CELSIUS OR
            FAHRENHEIT.  FOR NGS PURPOSES, CELSIUS          IS
            PREFERRED.  
  CC 35-38  WET BULB TEMPERATURE (XXX.x).  SEE DRY BULB
            TEMPERATURE.
  CC 39      WET BULB TEMPERATURE CODE (C/F).  SEE DRY BULB
         TEMPERATURE CODE.
  CC 40-42  RELATIVE HUMIDITY (XX.x).  ENTER THE PERCENTAGE OF
            RELATIVE HUMIDITY AT THE BEGINNING AND END OF THE
            SESSION.
  CC 43-48  BAROMETRIC PRESSURE (XXXX.xx).  (AT INITIATION AND
            COMPLETION) (ALLOWABLE UNITS MM, MB OR IN)  THE
            BAROMETRIC PRESSURE CAN ALSO BE FOUND ON THE WEATHER
            DATA SHEET.  
  CC 49-50  BAROMETRIC PRESSURE CODE.  (MM, MB, IN)  
              MM - MILLIMETERS OF MERCURY 
              MB - MILLIBARS 
              IN - INCHES OF MERCURY
  CC 51-55  WEATHER CODE.  THE FIRST COLUMN OF THIS CODE (51) IS A
            PROBLEM INDICATOR FOLLOWED BY VISIBILITY, TEMPERATURE,
            CLOUD COVER AND WIND INDICATORS IN SUCCESSION.  FOR
            INFORMATION CONCERNING THE WEATHER CODE TO BE USED IN
            CONNECTION WITH GEOMETRIC OBSERVATIONS, SEE CHAPTER 2,
            PAGES 2-10.   
  CC 56-80    BLANK 

                               2-52              GPS CLOCK SYNCHRONIZATION RECORD (*28)

The Clock Synchronization Record is used to record codeless type
receiver clock synchronization information.  Two records are
normally created for each receiver per day, i.e., one pre-session
and one post-session.  Use the Comment Record (*29*) immediately
following the *28* record for any comments.  This record is
required for codeless receivers.            

                            *28* FORMAT

  CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
            INCREMENT OF 10 FROM PREVIOUS RECORD. 
  CC 07-10  DATA CODE.  MUST BE *28*.
  CC 11-16  SYNCHRONIZATION DATE (YYMMDD) UTC.  CODELESS TYPE GPS
            RECEIVERS MUST BE TIME SYNCHRONIZED WITH OTHER
            RECEIVERS IN THE SESSION.  
  CC 17-20  SYNCHRONIZATION TIME (HHMM) UTC.  SEE SYNCHRONIZATION
            DATE.  
  CC 21-23  JOB-SPECIFIC INSTRUMENT NUMBER A.  THE UNIQUE THREE-
            DIGIT NUMBER IN THE RANGE 001 TO 999 ASSIGNED TO THE
            INSTRUMENT USED TO OBTAIN THIS OBSERVATION.  THIS
            NUMBER WILL CROSS REFERENCE THE NGS SURVEY EQUIPMENT
            CODE IN THE *70* RECORD.  
  CC 24-26  JOB-SPECIFIC INSTRUMENT NUMBER B.  SEE CC 21-23.
  CC 27-31  BLANK
  CC 32-36  TIMING DIFFERENCE (XXX.xx)(MICROSECONDS).
  CC 37     INTEGER TIME SECOND SYNCH (Y OR N).  
  CC 38-40  INITIALS OF THE OBSERVER.  
  CC 41-80      BLANK


              GPS CLOCK SYNCHRONIZATION RECORD (*29*)

Use this record for comments pertinent to the time synchronization
of two or more GPS receivers.  This record is optional. 

                            *29* FORMAT

  CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
            INCREMENT OF 10 FROM PREVIOUS RECORD.  
  CC 07-10  DATA CODE.  MUST BE *26*.
  CC 11-80  COMMENT.  IF THE COMMENT(S) EXCEED 70 CHARACTERS, USE
            ANOTHER *29* RECORD FOR CONTINUATION.  ANY NUMBER OF
            *29* RECORDS IS ALLOWED, BUT DO NOT DIVIDE WORDS
            BETWEEN CONSECUTIVE *29* RECORDS.  SEE CHAPTER 2,
            PAGES 2-17 AND 2-18, HORIZONTAL DIRECTION DATA
            RECORDS.










                                2-53
                HORIZONTAL ANGLE SET RECORD (*30*)

Use this record for the first angle of every set of angles
observed at a station.  Use the Horizontal Angle Record (*32*) for
the remaining angles observed in the same set.  Use a Comment 
Record (*31*) immediately following the *30* record for any
comments pertaining to the set of observations.

To anticipate the accuracy of an observation, the type of survey
equipment used must be known.  To identify the instrument used for
each observation, assign a unique three-digit number (Job-Specific
Instrument Number) in the range 001 to 999 to each item of survey
equipment used in the job.  Each number will cross reference a NGS
SURVEY EQUIPMENT CODE in the *70* record.  See Chapter 2, Page
2-10, Job-Specific Instrument Number and Page 2-28, Survey
Equipment Data       Records.


                                *30* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM PREVIOUS            RECORD.
   CC 07-10  DATA CODE.  MUST BE *30*.
   CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
   (STANDPOINT).               FOR ADDITIONAL INFORMATION SEE
   CHAPTER 1, PAGES 1-1 THRU 1-3, JOB            CODE AND SURVEY
   POINT NUMBERING; CHAPTER 2, PAGES 2-8 THRU 2-9,             
   OBSERVATION DATA RECORDS; PAGES 2-12 THRU 2-13, ASSIGNMENT OF   
               STATION SERIAL NUMBERS; AND PAGE 2-14, TREATMENT OF
   ECCENTRIC                OBSERVATIONS.
   CC 15-16  SET NUMBER.  ENTER 01 FOR THE FIRST SET OF ANGLE
   OBSERVATIONS.             EACH ADDITIONAL SET OF OBSERVED
                           ANGLES WITH THE SAME INSTRUMENT     
                           SSN MUST BE ASSIGNED A HIGHER NUMBER;
                           02, 03, ETC.  SEE CHAPTER 2,    PAGE 2-
                           20, SET NUMBER.
   CC 17-22  FIELD RECORD BOOK NUMBER.  VOLUME NUMBER OF THE FIELD
   BOOK IN            WHICH THE ANGLES OBSERVATIONS ARE
                    RECORDED.
   CC 23-24  NUMBER OF ANGLES OBSERVED IN THIS SET.  THIS NUMBER
   IS THE SUM OF            THE *30* RECORD AND THE *32*  RECORD
   (S) IN THIS SET.  SEE CHAPTER            2, PAGE 2-20.
   CC 25-29  WEATHER CODE.  THE FIRST COLUMN OF THIS CODE (25) IS
   A PROBLEM               INDICATOR FOLLOWED BY VISIBILITY,
   TEMPERATURE, CLOUD COVER AND               WIND INDICATORS IN
   SUCCESSION.  IF THE PROBLEM INDICATOR IS 1, A             *31*
   RECORD IS REQUIRED.  SEE CHAPTER 2, PAGE 2-10.
   CC 30-32  INITIALS OF THE OBSERVER.
   CC 33-35  JOB-SPECIFIC INSTRUMENT NUMBER (JSIN).  THE UNIQUE
   THREE-DIGIT               NUMBER IN THE RANGE 001 TO 999
   ASSIGNED TO THE INSTRUMENT USED TO            OBTAIN THIS
   OBSERVATION.  THIS NUMBER WILL CROSS REFERENCE THE NGS          
    SURVEY EQUIPMENT CODE IN THE *70* RECORD.
   CC 36-39  HEIGHT OF INSTRUMENT.  ENTER THE VERTICAL DISTANCE
   FROM THE TOP OF            THE OCCUPIED SURVEY MARK (POINT) TO
   THE OPTICAL CENTER OF THE                 SURVEYING INSTRUMENT. 
   IN METERS (MMmm).  SEE PAGE 2-11, HEIGHT OF           
   INSTRUMENT AND HEIGHT OF TARGET.




                                2-54
   CC 40-45  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD).  SEE
   CHAPTER 2,
              PAGE 2-20, DATE AND TIME.
   CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM) SEE CHAPTER 2,
   PAGE 2-7, TIME;           AND PAGE 2-20, DATE AND TIME.
   CC 50     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H  WHICH
   REPRESENTS
              THE TIME ZONE OCCUPIED.  SEE CHAPTER 2, PAGE 2-7.
   CC 51-54  STATION SERIAL NUMBER.  FIRST TARGET STATION (LEFT
   FOREPOINT).
              SEE CHAPTER 1, PAGES 1-1 THRU 1-3, JOB CODE AND
SURVEY POINT
              NUMBERING; CHAPTER 2, PAGES 2-12 THRU 2-13,
ASSIGNMENT OF STATION
              SERIAL NUMBERS; AND PAGE 2-14, TREATMENT OF
ECCENTRIC                            OBSERVATIONS.
   CC 55-58  HEIGHT OF TARGET. ENTER THE VERTICAL DISTANCE FROM
   THE TOP OF THE
              FIRST TARGET STATION (LEFT FOREPOINT) SURVEY MARK
(POINT) TO THE
              TARGET (POINT) ABOVE THE MARK USED FOR THE ANGLE
OBSERVATIONS. IN
              METERS (MMmm).  SEE CHAPTER 2, PAGE 2-11, HEIGHT OF
INSTRUMENT AND
              HEIGHT OF TARGET.
   CC 59     VISIBILITY CODE.  SEE CHAPTER 2, PAGE 2-11,
   VISIBILITY CODE.
   CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF DETERMINATIONS OF
   A SINGLE
              ANGLE MEASUREMENT WHICH ARE MEANED TO OBTAIN THE
DESIRED ANGLE
              VALUE. EACH DETERMINATION OF A SINGLE ANGLE WILL
USUALLY INVOLVE
              SEVERAL REPEATED MEASUREMENTS (REPETITIONS).  SEE
CHAPTER 2, PAGES
              2-19 AND 2-20, HORIZONTAL ANGLE DATA RECORDS.
   CC 62-63  REJECTION LIMIT. THE MAXIMUM ALLOWED DEVIATION OF A
   SINGLE ANGLE
              MEASUREMENT FROM THE MEAN OF ALL THE MEASUREMENTS
USED TO
              DETERMINE THE DESIRED ANGLE IN A SET.  SEE CHAPTER
2, PAGES 2-16.
   CC 64-71  CLOCKWISE ANGLE. MEAN OF FIRST ANGLE OBSERVED AT A
   STATION. IN
              DEGREES, MINUTES, SECONDS (DDDMMSSs).  SEE PAGES 2-
19 AND 2-20,
              HORIZONTAL ANGLE DATA RECORDS.
   CC 72-75  STATION SERIAL NUMBER.  SECOND TARGET STATION (RIGHT
   FOREPOINT).
              SEE PAGES 1-1 THRU 1-3, JOB CODE AND SURVEY POINT
NUMBERING; PAGES
              2-8 THRU 2-9, OBSERVATION DATA RECORDS; PAGES 2-12
THRU 2-13,
              ASSIGNMENT OF STATION SERIAL NUMBERS; AND PAGE 2-14,
TREATMENT OF
              ECCENTRIC OBSERVATIONS.
   CC 76-79  HEIGHT OF TARGET. ENTER THE VERTICAL DISTANCE FROM
   THE TOP OF THE
              SECOND TARGET STATION (RIGHT FOREPOINT) SURVEY MARK
(POINT) TO THE
              TARGET (POINT) ABOVE THE MARK USED FOR THE ANGLE
OBSERVATIONS.  IN
              METERS (MMmm).  SEE PAGE 2-11, HEIGHT OF INSTRUMENT
AND HEIGHT OF
              TARGET.
   CC 80     VISIBILITY CODE.  SEE PAGE 2-11, VISIBILITY CODE.














                                2-55
              HORIZONTAL ANGLE COMMENT RECORD (*31*)

   Use this record for comments pertaining to the set of angles. 
   This record is required to explain the problem encountered if
   the problem indicator (column 25) on the respective Horizontal
   Angle Set Record (*30*) is "1". Otherwise, this record is
   optional.

                            *31* FORMAT

   CC 01-06  SEQUENCE NUMBER. RIGHT JUSTIFIED.  MUST BE AN
   INCREMENT OF 10 FROM            THE PREVIOUS RECORD.
   CC 07-10  DATA CODE.  MUST BE *31*.
   CC 11-80  COMMENT. IF THE COMMENT(S) EXCEED 70 CHARACTERS, USE
   ANOTHER *31*            RECORD FOR CONTINUATION.  ANY NUMBER OF
   *31* RECORDS IS ALLOWED.             BUT, DO NOT DIVIDE WORDS
   BETWEEN CONSECUTIVE *31* RECORDS.  SEE              CHAPTER 2,
   PAGES 2-19 AND 2-20, HORIZONTAL ANGLE DATA RECORDS.





































                                2-56
                  HORIZONTAL ANGLE RECORD (*32*)

Use this record for the second and subsequent angles observed in
the same set.  Use a Horizontal Angle Set Record (*30*) for the
first angle observed in the set.

                                *32* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM PREVIOUS            RECORD.
   CC 07-10  DATA CODE.  MUST BE *32*.
   CC 11-14  STATION SERIAL NUMBER.  INSTRUMENT STATION
   (STANDPOINT).  FOR              ADDITIONAL INFORMATION REFER TO
   PAGES 1-1 THRU 1-3, 2-9 AND 2-12             THRU 2-13.
   CC 15-16  SET NUMBER.  MUST BE THE SAME NUMBER AS ON THE
   PRECEDING *30* 
            RECORD. 
   CC 17-45  BLANK.
   CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE CHAPTER 2,
   PAGE 2-7,                TIME; AND PAGE 2-20, DATE AND TIME.
   CC 50     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H THAT
   REPRESENTS                THE TIME ZONE OCCUPIED.  SEE CHAPTER
   2, PAGE 2-7.
   CC 51-54  STATION SERIAL NUMBER.  FIRST TARGET STATION (LEFT
   FOREPOINT).               SEE CHAPTER 1, PAGES 1-1 THRU 1-3,
   JOB CODE AND SURVEY POINT
              NUMBERING; CHAPTER 2, PAGES 2-12 THRU 2-13,
ASSIGNMENT OF STATION                SERIAL NUMBERS; AND PAGE 2-
14, TREATMENT OF ECCENTRIC                           
OBSERVATIONS.
   CC 55-58  HEIGHT OF TARGET.  ENTER THE VERTICAL DISTANCE FROM
   THE TOP OF THE            FIRST TARGET STATION (LEFT FOREPOINT)
   SURVEY MARK (POINT) TO THE             TARGET (POINT) ABOVE THE
   MARK USED FOR THE ANGLE OBSERVATIONS. IN            METERS
   (MMmm).  SEE CHAPTER 2, PAGE 2-11, HEIGHT OF INSTRUMENT AND     
         HEIGHT OF TARGET.
   CC 59     VISIBILITY CODE.  SEE CHAPTER 2, PAGE 2-11,
   VISIBILITY CODE.
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF DETERMINATIONS OF
A SINGLE                  ANGLE MEASUREMENT WHICH ARE MEANED TO
OBTAIN THE DESIRED ANGLE                   VALUE. EACH
DETERMINATION OF A SINGLE ANGLE WILL USUALLY INVOLVE                
    SEVERAL REPEATED MEASUREMENTS (REPETITIONS).  SEE CHAPTER 2,
PAGES                2-19 AND 2-20, HORIZONTAL ANGLE DATA RECORDS.
   CC 62-63  REJECTION LIMIT. THE MAXIMUM ALLOWED DEVIATION OF A
   SINGLE ANGLE 
              MEASUREMENT FROM THE MEAN OF ALL THE MEASUREMENTS
USED TO                        DETERMINE THE DESIRED ANGLE IN A
SET.  SEE CHAPTER 2, PAGE 2-16.       CC 64-71  CLOCKWISE ANGLE. 
MEAN OF FIRST ANGLE OBSERVED AT A STATION.  IN                
DEGREES, MINUTES, SECONDS (DDDMMSSs). SEE PAGES 2-19 AND 2-20,
              HORIZONTAL ANGLE DATA RECORDS.
   CC 72-75  STATION SERIAL NUMBER.  SECOND TARGET STATION (RIGHT
   FOREPOINT).        SEE PAGES 1-1 THRU 1-3, JOB CODE AND
                    SURVEY POINT NUMBERING; PAGES    2-8 THRU 2-9,
                    OBSERVATION DATA RECORDS; PAGES 2-12 THRU 2-
                    13,        ASSIGNMENT OF STATION SERIAL
                    NUMBERS; AND PAGE 2-14, TREATMENT OF   
                    ECCENTRIC OBSERVATIONS.





                                2-57
   CC 76-79  HEIGHT OF TARGET.  ENTER THE VERTICAL DISTANCE FROM
   THE TOP OF THE            SECOND TARGET STATION (RIGHT
   FOREPOINT) SURVEY MARK (POINT) TO THE            TARGET (POINT)
   ABOVE THE MARK USED FOR THE ANGLE OBSERVATIONS. IN           
   METERS (MMmm).  SEE PAGE 2-11, HEIGHT OF INSTRUMENT AND HEIGHT
   OF            TARGET.
   CC 80     VISIBILITY CODE.  SEE PAGE 2-11, VISIBILITY CODE.















































                                2-58
                 VERTICAL ANGLE SET RECORD (*40*)

Use this record for the first vertical angle (VA) or zenith 
distance (ZD)
observed in a set.  Use the Vertical Angle Record (*42*) for the
remaining vertical angles or zenith distances observed in the same
set.  Use a Comment Record (*41*) immediately following the *40*
record for any comments.  For additional information, refer to
pages 2-21 thru 2-23, VA/ZD Data Records.  

To anticipate the accuracy of an observation, the type of survey
equipment must be known.  To identify the instrument used for each
observation, assign a unique three-digit number (Job-Specific
Instrument Number) in the range 001 to 999 to each item of survey
equipment used in the job.  Each unique number will cross
reference a NGS Survey Equipment Code in the *70* record.   See
Page 2-10, Job-Specific Instrument Number and Page 2-28, Survey
Equipment Data Records.

                            *40* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM PREVIOUS            RECORD.
    CC 07-10  DATA CODE. MUST BE *40*
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).         CC 15-16  SET NUMBER.  ENTER 01 FOR THE
FIRST SET OF VA/ZD OBSERVATIONS.                   USE 02, 03,
ETC. FOR SUCCESSIVE SETS.  SEE PAGE 2-22, SET NUMBER. 
    CC 17-22  FIELD RECORD BOOK NUMBER.  VOLUME NUMBER OF THE
FIELD BOOK IN                    WHICH THE VA/ZD OBSERVATIONS ARE
RECORDED.
    CC 23-24  NUMBER OF VA OR ZD OBSERVATIONS IN THIS SET.  THIS
VALUE IS EQUAL                TO THE SUM OF THE *40* RECORD AND
THE *42* RECORD(S) IN THIS SET.                SEE PAGE 2-22.
    CC 25-29  WEATHER CODE.  THE FIRST COLUMN OF THIS CODE (25) IS
A PROBLEM                    INDICATOR FOLLOWED BY VISIBILITY,
                           TEMPERATURE, CLOUD COVER AND       WIND
                           INDICATORS IN SUCCESSION.  IF THE
                           PROBLEM INDICATOR IS "1", A    *41*
                           RECORD IS REQUIRED.  SEE PAGE 2-10,
                           WEATHER CODE.
    CC 30-32  INITIALS OF THE OBSERVER.
    CC 33-35  JOB-SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE-
DIGIT NUMBER                   ASSIGNED TO THE INSTRUMENT USED TO
OBTAIN THIS OBSERVATION.  SEE                 ABOVE.               
                          
   CC 36-39  HEIGHT OF INSTRUMENT.  ENTER THE VERTICAL DISTANCE
   FROM THE TOP OF            THE OCCUPIED SURVEY MARK (POINT) TO
   THE OPTICAL CENTER OF THE                SURVEYING INSTRUMENT. 
   IN METERS (MMmm).  SEE PAGE 2-11, HEIGHT OF           
   INSTRUMENT AND HEIGHT OF TARGET.
    CC 40-45  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD). 
SEE PAGE 2-24,                 DATE AND TIME.
    CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGES 2-7,
TIME AND 2-24,                DATE AND TIME.
    CC 50     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H WHICH
REPRESENTS                  THE TIME ZONE OCCUPIED.  SEE PAGE 2-7,
TIME ZONE.
    CC 51-54  STATION SERIAL NUMBER.  TARGET STATION (FOREPOINT).  
             





                                2-59
   CC 55-58  HEIGHT OF TARGET.  ENTER THE VERTICAL DISTANCE FROM
   THE TOP OF THE            TARGET STATION SURVEY MARK (POINT) TO
   THE TARGET (POINT) ABOVE THE            MARK USED FOR THE VA/ZD
   OBSERVATION.  IN METERS (MMmm).  REFER TO            PAGE 2-11,
   HEIGHT OF INSTRUMENT AND HEIGHT OF TARGET.
    CC 59     VISIBILITY CODE.  SEE PAGE 2-11.
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF POINTINGS OR
MEASUREMENTS USED                TO DETERMINE A VA OR ZD
OBSERVATION.  SEE PAGES 2-21 AND 2-22,                   VERTICAL
ANGLE/ZENITH DISTANCE DATA RECORDS.
    CC 62-63  REJECTION LIMIT. MAXIMUM ALLOWED SPREAD BETWEEN THE
OBSERVATIONS.                IN SECONDS (XXxx).
    CC 64-71  VERTICAL ANGLE OR ZENITH DISTANCE.  MEAN OF
POINTINGS OR                        MEASUREMENTS TO THE FIRST
OBJECT SIGHTED IN THE OBSERVING                        SEQUENCE. 
IN DEGREES, MINUTES, SECONDS (DDDMMSSs).  LEAVE CC 71               
BLANK IF VA OR ZD IS GIVEN TO THE NEAREST SECOND; LEAVE CC 69-71   
             BLANK IF IT IS GIVEN TO THE NEAREST MINUTE.
   CC 72     ANGLE CODE. INDICATE TYPE OF VERTICAL ANGLE MEASURED.
              E= ELEVATION, D= DEPRESSION, Z= ZENITH DISTANCE. 
SEE PAGE 2-22,                 ANGLE CODE.
    CC 73-76  INTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss). 
ENTER ONLY IF                   RELIABLE ESTIMATES ARE AVAILABLE. 
SEE PAGES 2-15 THRU 2-17,                     ACCURACY OF THE
OBSERVATIONS.
    CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN SECONDS PER
KILOMETER (SSss).                    ENTER ONLY IF RELIABLE
ESTIMATES ARE AVAILABLE.  SEE PAGES 2-15                  THRU
2-17, ACCURACY OF THE OBSERVATIONS.
                              

               VERTICAL ANGLE COMMENT RECORD (*41*)

Use this record for comments pertaining to the set of vertical
angles or zenith distances.  This record is required to explain
the problem encountered when the problem indicator (column 25) on
the preceding Vertical Angle Set Record (*40*) is "1".  Otherwise,
this record is optional.

                            *41* FORMAT

   CC 01-06  SEQUENCE NUMBER. RIGHT JUSTIFIED.  MUST BE AN
   INCREMENT OF 10 FROM          PREVIOUS RECORD.
   CC 07-10  DATA CODE.  MUST BE *41*.
   CC 11-80  COMMENT.  IF THE COMMENT(s) EXCEED 70 CHARACTERS, USE
   ANOTHER *41*           RECORD FOR CONTINUATION.  ANY NUMBER OF
   *41* RECORDS IS ALLOWED.            BUT, DO NOT DIVIDE WORDS
   BETWEEN CONSECUTIVE *41* RECORDS.












                                2-60
                   VERTICAL ANGLE RECORD (*42*)

Use this record for the second and subsequent vertical angles
(VAs) or zenith distances (ZDs) observed in the same set; use
Vertical Angle Set Record (*40*) for the first vertical angle or
zenith distance observed in the set.  Refer to pages 2-22 thru
2-24 for additional information.

                            *42* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM PREVIOUS            RECORD.
   CC 07-10  DATA CODE.  MUST BE *42*
   CC 11-14  STATION SERIAL NUMBER. INSTRUMENT STATION
   (STANDPOINT).  MUST BE                 IDENTICAL TO THE STATION
   SERIAL NUMBER (SSN) USED IN CC 11-14 ON             THE
   RESPECTIVE *40* RECORD.
   CC 15-16  SET NUMBER.  MUST BE THE SAME NUMBER AS ON THE
   PRECEDING *40*                RECORD.
   CC 17-45  BLANK.
   CC 46-49  LOCAL TIME. HOURS, MINUTES (HHMM).
   CC 50     TIME ZONE.  ENTER THE LETTER CODE FORM ANNEX H.
   CC 51-54  STATION SERIAL NUMBER (SSN).  TARGET STATION
   (FOREPOINT).   
   CC 55-58  HEIGHT OF TARGET.  ENTER THE VERTICAL DISTANCE FROM
   THE TOP OF THE            TARGET STATION SURVEY MARK (POINT) TO
   THE TARGET (POINT) ABOVE THE            MARK USED FOR THE VA/ZD
   OBSERVATION.  REFER TO PAGE 2-11, HEIGHT             OF
   INSTRUMENT AND HEIGHT OF TARGET.   
   CC 59     VISIBILITY CODE.  SEE PAGE 2-11.
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF POINTINGS OR
MEASUREMENTS USED                TO DETERMINE A VA OR ZD
OBSERVATION.  SEE PAGES 2-21 AND 2-22,                   VERTICAL
ANGLE/ZENITH DISTANCE DATA RECORDS.
    CC 62-63  REJECTION LIMIT. MAXIMUM ALLOWED SPREAD BETWEEN THE
OBSERVATIONS.                IN SECONDS (XXxx).
    CC 64-71  VERTICAL ANGLE OR ZENITH DISTANCE.  MEAN OF
POINTINGS OR MEASURE-                MENTS TO THE FIRST OBJECT
SIGHTED IN THE OBSERVING SEQUENCE. IN                  DEGREES,
MINUTES, SECONDS (DDDMMSSs).  LEAVE CC 71 BLANK IF VA OR           
  ZD IS GIVEN TO THE NEAREST SECOND; LEAVE CC 69-71 BLANK IF IT IS
                   GIVEN TO THE NEAREST MINUTE.
   CC 72     ANGLE CODE. INDICATE TYPE OF VERTICAL ANGLE MEASURED.
              E= ELEVATION, D= DEPRESSION, Z= ZENITH DISTANCE. 
SEE PAGE 2-22,                 ANGLE CODE.
   CC 73-76  INTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss). 
   ENTER ONLY IF               RELIABLE ESTIMATES ARE AVAILABLE. 
   SEE PAGES 2-15 THRU 2-17,                 ACCURACY OF THE
   OBSERVATIONS.
   CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN SECONDS PER KILOMETER
   (SSss).                ENTER ONLY IF RELIABLE ESTIMATES ARE
   AVAILABLE.  SEE PAGES 2-15
              THRU 2-17, ACCURACY OF THE OBSERVATIONS.








                                2-61
               DIFFERENCE OF ELEVATION RECORD (*45*)

Use this record for each observed difference of elevation obtained
by spirit leveling or by other than the trigonometric method coded
in the *40* thru *42* records.  Use the Difference of Elevation
Continuation Record (*47*) to code additional data pertinent to
the observation in the preceding *45* record. For any comments use
the Difference of Elevation Comment Record (*46*).  Refer to page
2-23, LEVEL DATA RECORDS, for additional information.

                            *45* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM THE                 PREVIOUS RECORD.
   CC 07-10  DATA CODE.  MUST BE *45*.
   CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
   (STANDPOINT).     CC 15-16  BLANK.                              
                                 CC 17-22  FIELD RECORD BOOK
   NUMBER.  VOLUME NUMBER OF THE FIELD BOOK IN               
   WHICH THE ELEVATION OBSERVATIONS ARE RECORDED.
   CC 23-24  BLANK.
   CC 25-29  WEATHER CODE.  THE FIRST COLUMN OF THIS CODE (25) IS
   A PROBLEM                 INDICATOR FOLLOWED BY VISIBILITY,
   TEMPERATURE, CLOUD COVER AND               WIND INDICATORS IN
   SUCCESSION.  IF THE PROBLEM INDICATOR IS "1", A            *46*
   RECORD IS REQUIRED.  SEE PAGE 2-10, WEATHER CODE.
   CC 30-32  INITIALS OF THE OBSERVER.
   CC 33-35  JOB-SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE-
   DIGIT NUMBER                 ASSIGNED TO THE INSTRUMENT USED TO
   OBTAIN THIS OBSERVATION.  REFER            TO PAGES 2-10 AND
   2-28.
   CC 36-38  NUMBER OF LEVELING SETUPS.  NUMBER OF TURNING POINTS
   USED TO                 OBTAIN THE ELEVATION DIFFERENCE OF THE
   SECTION OBSERVED.
   CC 39     BLANK.
   CC 40-45  DATE OF OBSERVATION. YEAR, MONTH, DAY (YYMMDD).
   CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGE 2-7,
   TIME AND 2-24,            DATE AND TIME.
   CC 50     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H TO
   INDICATE WHICH             TIME ZONE WAS OCCUPIED.  SEE PAGE
   2-7.
   CC 51-54  STATION SERIAL NUMBER.  TARGET STATION (FOREPOINT).
   CC 55-58  BLANK.
   CC 59     VISIBILITY CODE.  SEE PAGE 2-11.
   CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF MEASUREMENTS
   (LEVEL RUNNINGS)             OF THE SAME SECTION.  IF THE MEAN
   VALUE OF A FORWARD AND A                   BACKWARD LEVEL RUN
   OF THE SAME SECTION IS CODED AS A SINGLE                 
   OBSERVATION, THEN THE NUMBER OF REPLICATIONS SHOULD BE CODED AS
   2.
   CC 62-63  BLANK.
   CC 64-72  DIFFERENCE OF ELEVATION.  DIFFERENCE OF ELEVATION
   OBSERVED BETWEEN          TWO MARKS (A SECTION).  IN METERS
   (MMMMMmmmm).  IF THE DIFFERENCE            IS NEGATIVE, CODE
   THE MINUS SIGN (-) IMMEDIATELY PRECEDING THE              
   LEFTMOST DIGIT AND BLANK FILL COLUMNS LEFT OF THE MINUS SIGN.
   CC 73-76  ACCURACY OF LEVELING.  SIGMA IN MILLIMETERS (XXxx).
   ENTER ONLY IF          RELIABLE ESTIMATES ARE AVAILABLE.
   CC 77-80  LENGTH OF SECTION.  DISTANCE BETWEEN THE TWO MARKS
   FOR WHICH THE                ELEVATION DIFFERENCE WAS
   DETERMINED.  IN KILOMETERS (XXxx).


                                2-62
           DIFFERENCE OF ELEVATION COMMENT RECORD (*46*)

Use this record for comments pertaining to the difference of
elevation observations. If the problem indicator (column 25) on
the preceding Difference of Elevation Record (*45*) is "1", this
record is required to explain the problem encountered.  Otherwise,
this record is optional.

                            *46* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *46*
    CC 11-80  COMMENT.  IF THE COMMENT(S) EXCEED 7O CHARACTERS,
USE ANOTHER                    *46* RECORD FOR CONTINUATION.  ANY
NUMBER OF *46* RECORDS IS                     ALLOWED.  BUT, DO
NOT DIVIDE WORDS BETWEEN CONSECUTIVE *46*                     
RECORDS.

              DIFFERENCE OF ELEVATION CONTINUATION RECORD (*47*)

Use this record to indicate the Job-Specific Instrument (JSI)
Number of the leveling rod and the initials of the observing
agency.

                            *47* FORMAT

    CC 01-06  SEQUENCE NUMBER. RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                      PREVIOUS RECORD.
    CC 07-10  DATA CODE. MUST BE *47*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).                   MUST BE THE SAME SSN AS ON THE
PRECEDING *45* RECORD.   
    CC 15-16  BLANK.
    CC 17-54  BLANK.
    CC 55-57  JOB-SPECIFIC INSTRUMENT (JSIN) NUMBER.  THE UNIQUE
THREE-DIGIT                   NUMBER ASSIGNED TO THE LEVEL ROD
USED TO OBTAIN THIS OBSERVATION.                REFER TO PAGES
2-10 AND 2-28.                        
    CC 58-63  OBSERVING ORGANIZATION.  USE THE ABBREVIATION FOUND
IN ANNEX C                   WHICH IDENTIFIES THE ORGANIZATION
THAT OBSERVED THE DIFFERENCE OF                ELEVATION BETWEEN
THE TWO MARKS.  ANY ABBREVIATION NOT FOUND IN                 
ANNEX C MUST BE APPROVED BY NGS PRIOR TO SUBMITTING THE DATA.
    CC 64-80  BLANK.














                                2-63
                   TAPED DISTANCE RECORD (*50*)

Use this record for distances measured with either calibrated
(standardized) or uncalibrated steel or invar tapes.  Included are
distances consisting of any number of segments taped horizontally,
taped distances consisting of any number of segments which have
all been individually reduced to a common  horizontal reference
surface (other than the sea level or the ellipsoid) and one-
segment unreduced tape distances (less than or equal to one tape
length) measured along a slope.  Use the *52* record for taped
distances reduced to sea level or geoid, to the ellipsoid, or to
mark-to-mark.  See pages 2-24 thru 2-26, DISTANCE DATA RECORDS.


                            *50* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *50*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).
    CC 15-19  WEATHER CODE.  THE FIRST COLUMN OF THIS CODE (15) IS
A PROBLEM                   INDICATOR FOLLOWED BY VISIBILITY,
TEMPERATURE, CLOUD COVER AND                   WIND INDICATORS IN
SUCCESSION.  IF THE PROBLEM INDICATOR IS "1", A               
*55* RECORD IS REQUIRED.  SEE PAGE 2-10, WEATHER CODE.
    CC 20-22  INITIALS OF THE OBSERVER.
    CC 23-25  JOB-SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE-
DIGIT NUMBER                   ASSIGNED TO THE INSTRUMENT USED TO
OBTAIN THIS OBSERVATION.  REFER                TO PAGES 2-10 AND
2-28.
    CC 26-29  TAPE SUPPORT HEIGHT.  IN METERS (MMmm).  USED ONLY
FOR A CODE "S"                DISTANCE.  ENTER THE VERTICAL HEIGHT
OF THE TAPE SUPPORT (IF ANY)                ABOVE THE INSTRUMENT
STATION (STANDPOINT) MARK TO THE NEAREST                   
CENTIMETER (cm).
    CC 30-34  ELEVATION OF INSTRUMENT STATION (STANDPOINT).  IN
METERS (MMMMm).                FOR A CODE "H" DISTANCE ENTER THE
ELEVATION TO WHICH THE TAPED                   DISTANCE WAS
REDUCED.
    CC 35-40  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD).     
       
    CC 41-44  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGES 2-7,
TIME AND 2-25,                DATE AND TIME.
    CC 45     TIME ZONE.  ENTER THE LETTER FROM ANNEX H WHICH
REPRESENTS THE                   TIME ZONE OCCUPIED.  REFER TO
PAGE 2-7, TIME ZONE.
    CC 46-49  STATION SERIAL NUMBER.  TARGET STATION (FOREPOINT). 
    CC 50-53  TAPE SUPPORT HEIGHT.  IN METERS (MMmm).  USED ONLY
FOR A CODE "S"                DISTANCE.  ENTER THE VERTICAL HEIGHT
OF THE TAPE SUPPORT (IF ANY)                ABOVE THE TARGET
STATION (STANDPOINT) MARK TO THE NEAREST                       
CENTIMETER (cm).
    CC 54-58  DIFFERENCE OF ELEVATION.  IN METERS (MMmm).  USED
ONLY FOR A CODE                "S" DISTANCE.  ENTER THE DIFFERENCE
OF ELEVATION FROM MARK TO MARK                WITH RESPECT TO THE
INSTRUMENT STATION (STANDPOINT).
    CC 59     VISIBILITY CODE.  SEE BELOW OR PAGE 2-11.





                                2-64
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF COMPLETE
MEASUREMENTS OR                      DETERMINATIONS USED TO
CALCULATE THE MEAN TAPED DISTANCE CODED IN                THIS
RECORD.
    CC 62-63  REJECTION LIMIT.  IN MILLIMETERS (XX).  MAXIMUM
ALLOWED DEVIATION                OF OBSERVATIONS FROM THE MEAN .
    CC 64-72  CORRECTED TAPED DISTANCE.  IN METERS (MMMMMmmmm). 
TAPED HORIZON-                TAL (CODE T), REDUCED TO HORIZONTAL
(CODE H) OR SLOPE (CODE S)                   DISTANCE WITH
STANDARDIZATION, CATENARY AND TEMPERATURE                         
CORRECTIONS APPLIED AS APPLICABLE TO THE METHOD OF MEASUREMENT     
             AND/OR EQUIPMENT USED.                              
    CC 73     DISTANCE CODE.  SEE BELOW OR PAGE 2-26.
    CC 74-76  INTERNAL CONSISTENCY.  SIGMA IN MILLIMETERS (XXx).
ENTER ONLY IF                 RELIABLE ESTIMATES ARE AVAILABLE. 
REFER TO PAGES 2-15 THRU 2-17,                ACCURACY OF THE
OBSERVATIONS.
    CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN PARTS PER MILLION
(XXXx).  ENTER                 ONLY IF RELIABLE ESTIMATES ARE
AVAILABLE.  SEE PAGE 2-25.


                         VISIBILITY CODES
   
   Ŀ
       Code         Description                                   
  
                                                                  
  
        R           TARGET STATION (FOREPOINT) IS A REFERENCE
MARK   
                                                                  
  
        Z           TARGET STATION IS AN AZIMUTH MARK             
  
                                                                  
  
        V           TARGET STATION IS VISIBLE FROM THE GROUND     
  
                                                                  
  
        N           TARGET STATION IS NOT VISIBLE FROM THE GROUND 
  
   



                          DISTANCE CODES
   
   Ŀ
       Code         Description                                   
  
                                                                  
  
        T           TAPED HORIZONTAL DISTANCE                     
  
                                                                  
  
        H           TAPED SLOPE DISTANCE REDUCED TO HORIZONTAL    
                                                                 
               
        S           TAPED SLOPE DISTANCE (ONE TAPE LENGTH OR
LESS)                














                                2-65
                 UNREDUCED DISTANCE RECORD (*51*)

Use this record for slant-range distances less than 100 kilometers
in length, measured with electronic distance-measuring equipment
(DME).  Included are line-of-sight instrument-to-reflector
distances measured with electro-optical  DME and master-to-remote
distances measured with microwave DME.   Precision or resolution
of the measured distance must be 1 centimeter or better.  Use *53*
record for coarser resolution DME.  Instrument and/or reflector
calibration corrections and refraction correction are assumed to
have been  applied.  See pages 2-24 thru 2-26, DISTANCE DATA
RECORDS.

                            *51* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *51*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).         CC 15-19  WEATHER CODE.  SAME FORMAT AS THE
*50* RECORD.  SEE PAGE 2-10,                   WEATHER CODE.
    CC 20-22  INITIALS OF THE OBSERVER.
    CC 23-25  JOB SPECIFIC INSTRUMENT NUMBER (JSIN).  THE UNIQUE
THREE DIGIT                   NUMBER ASSIGNED TO THE INSTRUMENT
USED TO OBTAIN THIS OBSERVATION.             REFER TO PAGES 2-10
AND 2-28 FOR DETAILED EXPLANATION.
    CC 26-29  HEIGHT OF INSTRUMENT.  ENTER THE VERTICAL DISTANCE
FROM THE TOP OF                THE OCCUPIED SURVEY MARK (POINT) TO
THE OPTICAL CENTER OF THE                    SURVEYING INSTRUMENT. 
IN METERS (MMmm).  SEE PAGE 2-11, HEIGHT OF               
INSTRUMENT AND HEIGHT OF TARGET.
    CC 30-34  BLANK
    CC 35-40  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD).
    CC 41-44  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGES 2-7,
TIME AND 2-25,                DATE AND TIME.
    CC 45     TIME ZONE.  ENTER THE LETTER CODE FORM ANNEX H WHICH
REPRESENTS                  THE TIME ZONE OCCUPIED.  REFER TO PAGE
2-7, TIME ZONE.
    CC 46-49  STATION SERIAL NUMBER (SSN).  TARGET STATION
(FOREPOINT).              CC 50-53  HEIGHT OF REFLECTOR.  ENTER
THE VERTICAL DISTANCE FROM THE TOP OF                THE TARGET
STATION SURVEY MARK TO THE REFLECTOR ABOVE THE MARK                
  USED FOR THE DISTANCE OBSERVATION IN METERS (MMmm).  REFER TO    
              PAGE 2-11, HEIGHT OF INSTRUMENT AND HEIGHT OF
TARGET.
    CC 54-58  BLANK
    CC 59     VISIBILITY CODE.  SEE PAGE 2-11 OR SEE TEXT FOR THE
*50* RECORD                  FORMAT.
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF COMPLETE
MEASUREMENTS OR                      DETERMINATIONS USED TO
CALCULATE THE MEAN CORRECTED SLANT-RANGE                  DISTANCE
CODED IN THIS RECORD.
    CC 62-63  REJECTION LIMIT.  MAXIMUM ALLOWED DEVIATION OF
OBSERVATIONS FROM                 THE MEAN VALUE.  IN MILLIMETERS.
    CC 64-72  CORRECTED SLANT-RANGE DISTANCE.  IN METERS
(MMMMMmmmm).                          CORRECTIONS FOR THE
INSTRUMENT, REFLECTOR AND REFRACTION ARE                    
ASSUMED APPLIED AS APPLICABLE TO THE METHOD OF MEASUREMENT AND/OR  
             THE EQUIPMENT USED
    CC 73     DISTANCE CODE.  MUST BE "S".


                                2-66
    CC 74-76  INTERNAL CONSISTENCY.  SIGMA IN MILLIMETERS (XXx). 
ENTER ONLY IF                RELIABLE ESTIMATES ARE AVAILABLE. 
REFER TO PAGES 2-15 THRU 2-17,                ACCURACY OF THE
OBSERVATIONS.
    CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN PARTS PER MILLION
(XXXx).  ENTER                 ONLY IF RELIABLE ESTIMATES ARE
AVAILABLE.  SEE PAGE 2-25.
















































                                2-67
                  REDUCED DISTANCE RECORD (*52*)


Use this record for distances of less than 100 kilometers in
length, measured to a precision of 1 centimeter or better that
have been reduced to sea level or the geoid (code G), to the
ellipsoid (code E), or to mark-to-mark (code X).  Use *54* record
for coarser-precision distances.  This record is intended for
taped distances and distances measured with electronic DME.  In
every case, the distance given is assumed to be the appropriately
reduced value corresponding to the mean of the respective sample
of distance measurements to which all applicable corrections have
been applied.  Among the required data items on this record are
the values of the elevations (and of the geoid heights, if
applicable) which were used in the respective reduction process. 
These values may be different than those given on the
corresponding *80*-series  records.

                            *52* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *52*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).         CC 15-19  WEATHER CODE.  SAME FORMAT AS *50*
AND *51* RECORDS.
    CC 20-22  INITIALS OF THE OBSERVER.
    CC 23-25  JOB SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE
DIGIT NUMBER                   ASSIGNED TO THE INSTRUMENT USED TO
OBTAIN THIS MEASUREMENT.  SEE                 PAGES 2-10 AND 2-28.
    CC 26-29  GEOID HEIGHT.  IN METERS (MMMm).  VALUE USED IN THE
REDUCTION                    PROCESS.  LEAVE BLANK FOR CODE "G"
DISTANCE.  IF THE GEOID HEIGHT                IS NEGATIVE, CODE
THE MINUS SIGN (-) IMMEDIATELY PRECEDING THE                  
LEFTMOST DIGIT AND BLANK FILL COLUMNS LEFT OF THE MINUS SIGN.
    CC 30-34  ELEVATION OF THE INSTRUMENT STATION (STANDPOINT)
MARK.  RECORD THE                VALUE USED IN THE REDUCTION
PROCESS.  IN METERS (MMMMm).
    CC 35-40  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD).  
    CC 41-44  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGE 2-7,
TIME.
    CC 45     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H WHICH
APPLIES.
    CC 46-49  STATION SERIAL NUMBER (SSN).  TARGET STATION
(FOREPOINT).              CC 50-53  GEOID HEIGHT.  IN METERS
(MMMm).  VALUE USED IN THE REDUCTION                    PROCESS. 
LEAVE BLANK FOR CODE "G" DISTANCE.  IF THE GEOID HEIGHT            
   IS NEGATIVE, CODE THE MINUS SIGN (-) IMMEDIATELY PRECEDING THE  
                LEFTMOST DIGIT AND BLANK FILL COLUMNS LEFT OF THE
MINUS SIGN.
    CC 54-58  ELEVATION OF THE TARGET STATION (FOREPOINT) MARK.
RECORD THE VALUE                USED IN THE REDUCTION PROCESS.  IN
METERS (MMMMm).  
    CC 59     VISIBILITY CODE.  SEE PAGE 2-12 OR THE TABLE BELOW.
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF MEASUREMENTS USED
TO CALCULATE                THE MEAN REDUCED DISTANCE CODED IN
THIS RECORD.
    CC 62-63  REJECTION LIMIT.  MAXIMUM ALLOWED DEVIATION OF
MEASUREMENTS FROM                 THE MEAN VALUE.  IN MILLIMETERS
(XX).






                                2-68
    CC 64-72  REDUCED DISTANCE.  IN METERS (MMMMMmmmm).  ENTER
DISTANCE REDUCED                TO SEA LEVEL OR THE GEOID (CODE
G), TO THE ELLIPSOID (CODE E), OR                TO MARK-TO-MARK
(CODE X).  DO NOT ENTER TO MORE DECIMAL PLACES                  
THAN IS WARRANTED BY THE PRECISION OF THE OBSERVATION.
    CC 73     DISTANCE CODE.  SEE PAGE 2-26 OR THE TABLE BELOW.
    CC 74-76  INTERNAL CONSISTENCY.  SIGMA IN MILLIMETERS (XXx). 
ENTER ONLY IF                RELIABLE ESTIMATES ARE AVAILABLE. 
REFER TO PAGES 2-15 THRU 2-17,                ACCURACY OF THE
OBSERVATIONS.
    CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN PARTS PER MILLION
(XXXx).  ENTER                 ONLY IF RELIABLE ESTIMATES ARE
AVAILABLE.  SEE PAGE 2-25 AND PAGES                2-15 THRU 2-17,
ACCURACY OF THE OBSERVATIONS.  


                         VISIBILITY CODES
   
   Ŀ
       Code         Description                                   
  
                                                                  
  
        R           TARGET STATION (FOREPOINT) IS A REFERENCE
MARK   
                                                                  
  
        Z           TARGET STATION IS AN AZIMUTH MARK             
  
                                                                  
  
        V           TARGET STATION IS VISIBLE FROM THE GROUND     
  
                                                                  
  
        N           TARGET STATION IS NOT VISIBLE FROM THE GROUND 
  
   



                      REDUCED DISTANCE CODES
   
   Ŀ
       Code         Description                                   
  
                                                                  
  
        G           MEASURED DISTANCES REDUCED TO THE GEOID       
  
                                                                  
  
        E           MEASURED DISTANCES REDUCED TO THE ELLIPSOID   
                                                                 
               
        X           MEASURED DISTANCES REDUCED TO MARK-TO-MARK    
               



















                                2-69
                 UNREDUCED LONG LINE RECORD (*53*)
  
Use this record for instrument-to-instrument spatial-chord
distances derived from long-range electronic DME observations 
(e.g., HIRAN), obtained by extra-terrestrial methods (e.g., VLBI),
or for slant-range distances measured by coarse-resolution DME.  
This record is intended for measured distances of 100 kilometers
and longer.  Since long-line and/or course-resolution distance 
measurements do not normally exhibit any proportional relationship
with the length of the line, the External Consistency Sigma on the
*53* and *54* records is expressed in meters.                      
                           

                            *53* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *53*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).  
    CC 15-22  BLANK
    CC 23-25  JOB SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE
DIGIT NUMBER                   ASSIGNED TO THE INSTRUMENT USED TO
OBTAIN THIS MEASUREMENT.  SEE                 PAGES 2-10 AND 2-28.
    CC 26-29  HEIGHT OF INSTRUMENT (ANTENNA).  IN METERS (MMmm).
ENTER THE                     VERTICAL DISTANCE FROM THE TOP OF
THE INSTRUMENT STATION                         (STANDPOINT) MARK
TO THE ACTUAL ORIGIN OF THE MEASURED DISTANCE                 
ABOVE/BELOW THE MARK.
    CC 30-34  BLANK
    CC 35-40  DATE OF OBSERVATION.  YEAR, MONTH, DAY (YYMMDD).    

    CC 41-44  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGE 2-25,
DATE AND TIME.
    CC 45     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H WHICH
REPRESENTS                  THE TIME ZONE OCCUPIED.  REFER TO PAGE
2-7, TIME ZONE.
    CC 46-49  STATION SERIAL NUMBER (SSN).  TARGET STATION
(FOREPOINT).              CC 50-53  HEIGHT OF INSTRUMENT
(ANTENNA).  IN METERS (MMmm).  ENTER THE                   
VERTICAL DISTANCE FROM THE TOP OF THE TARGET STATION (FOREPOINT)   
             MARK TO THE ACTUAL TERMINAL POINT OF THE MEASURED
DISTANCE                       ABOVE/BELOW THE MARK.               
               
    CC 54-58  BLANK
    CC 59-60  NUMBER OF REPLICATIONS.  NUMBER OF COMPLETE
MEASUREMENTS USED TO                 CALCULATE THE MEAN CORRECTED
SLANT-RANGE DISTANCE CODED IN THIS                  RECORD.
    CC 61-63  REJECTION LIMIT.  MAXIMUM ALLOWED DEVIATION OF
OBSERVATIONS FROM                 THE MEAN VALUE.  IN METERS
(MMm).
    CC 64-73  CORRECTED SPATIAL-CHORD DISTANCE.  DERIVED
INSTRUMENT-TO-                        INSTRUMENT (ANTENNA-TO-
ANTENNA) SPACIAL-CHORD (CODE C) OR                       
DIRECTLY-OBSERVED SLANT RANGE (CODE S) WITH ALL APPLICABLE         
             CORRECTIONS APPLIED.  IN METERS (MMMMMMMmmm).
    CC 74     DISTANCE CODE.  SEE ABOVE.   
    CC 57-77  INTERNAL CONSISTENCY.  SIGMA IN METERS (Mmm).  ENTER
ONLY IF                     RELIABLE ESTIMATES ARE AVAILABLE. 
REFER TO PAGES 2-15 THRU 2-17,                ACCURACY OF THE
OBSERVATIONS.
    CC 78-80  EXTERNAL CONSISTENCY.  SIGMA IN METERS (Mmm).  ENTER
ONLY IF                     RELIABLE ESTIMATES ARE AVAILABLE.  SEE
PAGE 2-25.


                                2-70
                  REDUCED LONG LINE RECORD (*54*)

Use this record for long lines, 100 kilometers and longer, or for
any distances measured to a precision coarser than 1 centimeter,
which have been reduced to sea level or the geoid (Code G), to the
ellipsoid (Code E), or to mark-to-mark spatial-chord distance
(Code X).  Since the predominate external random errors associated
with long-line and/or coarse-resolution distance measurements do
not normally exhibit any proportional relationship with the length
of the line, the External Consistency Sigma on the *53* and *54*
records is expressed in meters.

                            *54* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM THE                 PREVIOUS RECORD.
   CC 07-10  DATA CODE.  MUST BE *54*.
   CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
   (STANDPOINT).
   CC 15-22  BLANK
   CC 23-25  JOB SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE
   DIGIT NUMBER               ASSIGNED TO THE INSTRUMENT USED TO
   OBTAIN THIS MEASUREMENT.  SEE              PAGES 2-10 AND 2-28.
   CC 26-29  GEOID HEIGHT.  IN METERS (MMMm).  VALUE USED IN THE
   REDUCTION                PROCESS FOR THE INSTRUMENT STATION
   (STANDPOINT).  LEAVE BLANK FOR            CODE G DISTANCE.  IF
   THE GEOID HEIGHT IS NEGATIVE, CODE THE MINUS            SIGN (-
   ) IMMEDIATELY PRECEDING THE LEFTMOST DIGIT AND BLANK FILL       
        THE COLUMNS LEFT OF THE MINUS SIGN.
   CC 30-34  ELEVATION OF THE INSTRUMENT STATION (STANDPOINT)
   MARK.  RECORD THE            VALUE USED IN THE REDUCTION
   PROCESS.  (POSSIBLY DIFFERENT THAN THE            ELEVATION
   GIVEN ON THE CORRESPONDING *80* OR *81* RECORD.  IN             
     METERS (MMMMm).
   CC 35-40  DATE OF OBSERVATION.  YEAR, MONTH, DAY  (YYMMDD).
   CC 41-44  LOCAL TIME.  HOURS, MINUTES (HHMM).
   CC 45     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H WHICH
   REPRESENTS              THE TIME ZONE OCCUPIED.
   CC 46-49  STATION SERIAL NUMBER (SSN).  TARGET STATION
   (FOREPOINT). 
   CC 50-53  GEOID HEIGHT.  IN METERS (MMMm).  VALUE USED IN THE
   REDUCTION                PROCESS FOR THE TARGET STATION
   (FOREPOINT).  LEAVE BLANK FOR CODE            G DISTANCE.  IF
   THE GEOID HEIGHT IS NEGATIVE, CODE THE MINUS SIGN            (-
   ) IMMEDIATELY PRECEDING THE LEFTMOST DIGIT AND BLANK FILL THE   
             COLUMNS LEFT OF THE MINUS SIGN.
   CC 54-58  ELEVATION OF THE TARGET STATION (FOREPOINT) MARK. 
   RECORD THE                VALUE USED IN THE REDUCTION PROCESS
   (POSSIBLY DIFFERENT THAN THE             ELEVATION GIVEN ON THE
   CORRESPONDING *80* OR *81* RECORD.  IN                METERS
   (MMMMm).
   CC 59-60  NUMBER OF REPLICATIONS.  NUMBER OF COMPLETE
   MEASUREMENTS USED TO             CALCULATE THE MEAN REDUCED
   OBSERVATION CODED IN THIS RECORD.
   CC 61-63  REJECTION LIMIT.  MAXIMUM ALLOWED DEVIATION OF
   MEASUREMENTS FROM             THE MEAN VALUE.  IN METERS (MMm).






                               2-71
   CC 64-73  REDUCED DISTANCE.  IN METERS (MMMMMMMmmm).  ENTER
   DISTANCE REDUCED          TO SEA LEVEL OR THE GEOID (CODE
                           G), TO THE ELLIPSOID (CODE E), OR    TO
                           MARK-TO-MARK (CODE X).  DO NOT ENTER TO
                           MORE DECIMAL PLACES       THAN IS
                           WARRANTED BY THE PRECISION OF THE
                           OBSERVATION.
   CC 74     DISTANCE CODE.  ENTER THE APPROPRIATE G, E, OR X
   DESCRIBED ABOVE             AND ON PAGE 2-28.
   CC 75-77  INTERNAL CONSISTENCY.  SIGMA IN METERS (Mmm).  ENTER
   ONLY IF                  RELIABLE ESTIMATES ARE AVAILABLE. 
   REFER TO PAGES 2-15 THRU 2-17,      ACCURACY OF THE
                                     OBSERVATIONS.
   CC 78-80  EXTERNAL CONSISTENCY.  SIGMA IN METERS (Mmm).  ENTER
   ONLY IF                  RELIABLE ESTIMATES ARE AVAILABLE.  SEE
   PAGES 2-25 AND PAGES 2-15                 THRU 2-17, ACCURACY
   OF THE OBSERVATIONS.


             HORIZONTAL DISTANCE COMMENT RECORD (*55*)

Use this record for comments pertaining to the set of observed
horizontal distances.  This record is required to explain the
problem encountered when the problem indicator (column 15) on the
preceding Horizontal Distance Records (*50*, *51*, or *52*) is
"1".  Otherwise, this record is optional.

                            *55* FORMAT

   CC 01-06  SEQUENCE NUMBER. RIGHT JUSTIFIED.  MUST BE AN
   INCREMENT OF 10 FROM          PREVIOUS RECORD.
   CC 07-10  DATA CODE.  MUST BE *55*.
   CC 11-80  COMMENT.  IF THE COMMENT(s) EXCEED 70 CHARACTERS, USE
   ANOTHER *55*           RECORD FOR CONTINUATION.  ANY NUMBER OF
   *55* RECORDS IS ALLOWED.            BUT, DO NOT DIVIDE WORDS
   BETWEEN CONSECUTIVE *55* RECORDS.
























                               2-72
             ASTRONOMIC AZIMUTH/LAPLACE RECORD (*60*)

Submit this record for every astronomic azimuth observed in the
project.  If two or more sets of astronomic azimuth observations
are taken (e.g., sets observed on different nights), submit a
separate *60* record for each set.                                

The desired astronomic azimuth coded in this record is the mean
value of the respective set of astronomic observations to which
all applicable corrections have been applied.

A Laplace azimuth is an astronomic azimuth determination (from
observations of a star) converted to the corresponding geodetic
azimuth by the application of the Laplace correction (n * tan L). 
A data element necessary for the computation of a Laplace
correction is the east-west (prime-vertical) component of the
deflection of vertical (eta) at the respective instrument station
(standpoint).  Use the following formula to compute a Laplace
azimuth:

             G =  A + n * tan L

   where :       G =  geodetic azimuth (d,m,s)
             A =  astronomic azimuth (d,m,s)
             n =  eta (seconds)
             L =  geodetic latitude of the instrument station
             (standpoint)                            
If a reliable Eta value is unavailable, submit the *60* record
with blanks in columns 15-19 and enter a code "A" in column 20 to
designate the azimuth in columns 64-71 as Astronomic.  Enter a
code "L" in column 20 to designate the azimuth in columns 64-71 as
Laplace, indicating that the Laplace correction has been applied.

                                *60* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *60*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).         CC 15-18  PRIME-VERTICAL COMPONENT OF
DEFLECTION (ETA) VALUE USED IN LAPLACE                CORRECTION. 
IN SECONDS (SSSs).
    CC 19     DIRECTION OF ETA.  ENTER CODE "E" FOR EAST OR CODE
"W" FOR WEST.
    CC 20     COMPUTATION CODE.  ENTER CODE "A" FOR ASTRONOMIC OR
CODE "L" FOR                 LAPLACE.      
    CC 21-29  BLANK 
    CC 30-32  INITIALS OF THE OBSERVER.
    CC 33-35  JOB-SPECIFIC INSTRUMENT NUMBER.  THE UNIQUE THREE-
DIGIT NUMBER                   ASSIGNED TO THE INSTRUMENT USED TO
OBTAIN THIS OBSERVATION.  REFER                TO PAGES 2-10 AND
2-28.
    CC 36-39  HEIGHT OF INSTRUMENT.  ENTER THE VERTICAL DISTANCE
FROM THE TOP OF                THE INSTRUMENT STATION (STANDPOINT)
MARK TO THE OPTICAL CENTER OF                THE SURVEYING
INSTRUMENT.  IN METERS (MMmm).  SEE PAGE 2-11,                    
HEIGHT OF INSTRUMENT AND HEIGHT OF TARGET.



                                2-73
    CC 40-45  DATE OF OBSERVATION.  YEAR, MONTH, DAY  (YYMMDD).
    CC 46-49  LOCAL TIME.  HOURS, MINUTES (HHMM).  SEE PAGES 2-7,
TIME AND 2-27,                DATE AND TIME.
    CC 50     TIME ZONE.  ENTER THE LETTER CODE FROM ANNEX H WHICH
REPRESENTS                  THE TIME ZONE OCCUPIED.  REFER TO PAGE
2-7, TIME ZONE.          
    CC 51-54  STATION SERIAL NUMBER.  TARGET STATION (FOREPOINT). 
    CC 55-58  HEIGHT OF TARGET.  ENTER THE VERTICAL DISTANCE.
    CC 59     VISIBILITY CODE.  SEE PAGE 2-11.
    CC 60-61  NUMBER OF REPLICATIONS.  NUMBER OF COMPLETE
MEASUREMENTS OR                      DETERMINATIONS USED TO
CALCULATE THE MEAN CORRECTED AZIMUTH                     
OBSERVATION IN THIS RECORD.
    CC 62-63  REJECTION LIMIT.  MAXIMUM ALLOWED DEVIATION OF
OBSERVATIONS FROM                 THE MEAN VALUE.  IN SECONDS.
    CC 64-71  ASTRONOMIC/LAPLACE AZIMUTH.  DEGREES, MINUTES,
SECONDS                           (DDDMMSSs).  ASTRONOMIC AZIMUTH
OBSERVATION (MEAN OF ONE SET)                    WITHOUT THE
LAPLACE CORRECTION APPLIED (CODE A) OR WITH THE                    
 LAPLACE CORRECTION APPLIED (CODE L).  DO NOT APPLY A SKEW NORMAL, 
              GEODESIC, OR DEFLECTION CORRECTION.
    CC 72     ORIGIN OF AZIMUTH.  ENTER CODE "N" FOR NORTH OR CODE
"S" FOR                     SOUTH.
    CC 73-76  INTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss). 
ENTER ONLY IF A                 RELIABLE ESTIMATE IS AVAILABLE. 
REFER TO PAGES 2-15 THRU 2-17.
    CC 77-80  EXTERNAL CONSISTENCY.  SIGMA IN SECONDS (SSss). 
ENTER ONLY IF A                 RELIABLE ESTIMATE IS AVAILABLE.





























                                2-74
                  GEODETIC AZIMUTH RECORD (*61*)

Use this record for each computed geodetic azimuth used to orient
this survey project.  Record either a published azimuth to an
azimuth mark from a previously established (published) control
station that was occupied in this project, or geodetic azimuth
obtained from an inverse position computation.

                            *61* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *61*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  INSTRUMENT STATION
(STANDPOINT).  
    CC 15-50  BLANK
    CC 51-54  STATION SERIAL NUMBER (SSN).  TARGET STATION
(FOREPOINT).         
    CC 55-63  BLANK
    CC 64-71  GEODETIC AZIMUTH.  DEGREES, MINUTES, SECONDS
(DDDMMSSs).
    CC 72     ORIGIN OF AZIMUTH.  CODE "N" FOR NORTH OR CODE "S"
FOR SOUTH.
    CC 73-80  BLANK


































                                2-75
                     INSTRUMENT RECORD  (*70*)

Use this record to provide descriptive information for each item
of survey equipment used in the job.  This information will be
used as an accuracy indicator for each observation in the survey. 
Assign a unique three-digit number Job-Specific Instrument Number
(JSIN), to each piece of equipment used in the project.  This
record will cross-reference the assigned JSIN to the NGS Survey
Equipment Codes found in Annex F.  More than one *70* record is
required for any instrument used for more than one type of
measurement.  See Chapter 2,   page 2-28, Survey Equipment Data
Records.

                           *70* FORMAT 

    CC 01-06 SEQUENCE NUMBER.  RIGHT JUSTIFIED.  MUST BE AN
INCREMENT OF 10                   FROM THE PREVIOUS RECORD.
    CC 07-10 DATA CODE.  MUST BE *70*.
    CC 11-13 JOB-SPECIFIC INSTRUMENT NUMBER (JSIN).  MUST BE
UNIQUE FOR EACH                  INSTRUMENT IN JOB.  SEE PAGES 2-
10 AND 2-28.
    CC 14-16 NGS SURVEY EQUIPMENT CODE.  SEE ANNEX F.  USED TO
IDENTIFY THE                   INSTRUMENT WHICH WAS ASSIGNED THE
JSIN IN CC 11-13 ABOVE.
    CC 17-20 RESOLUTION OF THE INSTRUMENT.  RECORD THE SIZE OF THE
SMALLEST                   DIRECTLY READABLE MEASUREMENT UNIT OR
THE RESOLUTION PUBLISHED                   BY THE INSTRUMENT
MANUFACTURER, WHICHEVER IS LARGER (XXxx).
    CC 21-22 UNITS.  UNITS OF THE RESOLUTION USED IN CC 17-20
ABOVE.  SEE                     PAGE 2-28, RESOLUTION OF THE
INSTRUMENT AND UNITS.
    CC 23-40 MANUFACTURER OF THE INSTRUMENT.  SEE ANNEX F. 
(EXAMPLES:  WILD,                  ZEISS/JENA, HEWLETT PACKARD).
    CC 41-62 TYPE OF INSTRUMENT OR TRADE NAME.  SEE ANNEX F. 
(EXAMPLES;                      DIRECTION THEODOLITE, CALIB INVAR
TAPE, RANGE MASTER,                            TELLUROMETER).
    CC 63-70 MODEL OR CLASS OF INSTRUMENT.  SEE ANNEX F.
(EXAMPLES:  T-3,                     MA-100, 30-MT, 100-FT).
    CC 71-80 SERIAL NUMBER.  ALPHANUMERIC AND LEFT JUSTIFIED. 
LEAVE BLANK IF                  THE SERIAL NUMBER IS NOT KNOWN.    
                                


















                                2-76
                    CONTROL POINT RECORD (*80*)

Use this record for the designation (name) and geographic position
in geodetic coordinates (latitude and longitude) of each control
point in the project.
If the position is given in Universal Transverse Mercator (UTM)
coordinates or in State Plane Coordinates (SPC), use the *81*
record.  The geodetic position of every horizontal control point
for which a *80* record is submitted must be provided in order to
serve as either a fixed (constrained) position or as a preliminary
position in the adjustment of the horizontal control survey
project.

NOTE:  Although columns 70-75 and column 76 of this record are
currently used for recording the elevation and elevation code, NGS
may discontinue this in the near future.  NGS prefers that you use
the new *86* record for this purpose.

For every *80* or *81* record submitted, the elevation of each
control point must be provided, except for unmonumented
recoverable landmarks positioned by intersection.  For such
landmarks, the elevation field may be left blank.  However, when
the elevation of an unmonumented recoverable landmark is given, it
should be the ground level elevation and the height above ground
level of the point actually sighted should be entered as the
height of target on the respective observation record.

The first character of the order and type code indicates the order
of accuracy of the main-scheme network in the project.  It
reflects the surveying methods used, procedures followed and
specifications enforced to obtain the observations of the project.

The second character of the order and type code indicates the type
of survey scheme of which the control point in question is a part
and/or the (primary) surveying method used to position the control
point.  Refer to pages 2-35 thru 2-38 for additional information.


                     TABLE OF ELEVATION CODES

   CODE   EXPLANATION

   A      The control point is a bench mark (BM) in the NGSIDB.
   B      BM determined using FGCS/NGS procedures but not in the
          NGSIDB.
   C      The control point is a 'posted' bench mark.
   H      OHT determined using FGCS procedures but tied to only
          one (1) BM.
   L      OHT established using NGS leveling RESET procedures.
   F      OHT established using fly-leveling.
   T      OHT determined by leveling between control points which
          are not BMs.
   R      OHT determined by reciprocal vertical angles.
   V      OHT determined by non-reciprocal vertical angles.
   P      OHT determined by a photogrammetric method.
   M      OHT scaled from a topographic map.
   G      OHT determined from an ellipsoidal height.
   D      OHT determined by datum transformation.
            


                                2-77
                                *80* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE. MUST BE *80*.
    CC 11-14  STATION SERIAL NUMBER (SSN). SEE PAGES 1-1, JOB CODE
AND SURVEY                  POINT NUMBERING AND 2-12, ASSIGNMENT
OF STATION SERIAL NUMBERS.
    CC 15-44  STATION NAME.  MUST NOT EXCEED 30 CHARACTERS.  THE
NAME OF A                     HORIZONTAL CONTROL POINT WITH
PERIPHERAL REFERENCE MARKS AND/OR                  AZIMUTH MARKS
MUST NOT EXCEED 24 CHARACTERS TO ALLOW FOR ADDING RM               
1, RM 2, AND/OR AZ MK TO THE NAME WITHOUT EXCEEDING THE 30         
             CHARACTER LENGTH LIMIT.
    CC 45-55  LATITUDE. DEGREES, MINUTES, SECONDS (DDMMSSsssss). 
    CC 56     DIRECTION OF LATITUDE.  RECORD CODE "N" FOR NORTH OR
CODE "S" FOR                SOUTH.
    CC 57-68  LONGITUDE. DEGREES, MINUTES, SECONDS,
(DDDMMSSsssss).
    CC 69     DIRECTION OF LONGITUDE. RECORD CODE "E" FOR EAST OR
CODE "W" FOR                 WEST.

NGS PREFERS THAT YOU USE THE NEW *86* RECORD FOR RECORDING THE
ELEVATION (ORTHOMETRIC HEIGHT) AND ELEVATION CODE INSTEAD OF THE
TWO DATA FIELDS THAT FOLLOW.  REFER TO PAGES 2-83 THRU 2-85.

    CC 70-75  ELEVATION.  RECORD ELEVATION OF MARK ABOVE MEAN SEA
LEVEL.  IN                   METERS (MMMMmm).  ENTER THE ELEVATION
TO THE NEAREST CENTIMETER                  (cm).  IF MEASUREMENT
IS ONLY OBSERVED TO THE NEAREST DECIMETER                  (dm),
LEAVE CC 75 BLANK, IF OBSERVED ONLY TO THE NEAREST METER           
       (M), LEAVE CC 74-75 BLANK.  THE APPROPRIATE ELEVATION CODE
MUST
              BE ENTERED IN CC 76.  REFER TO PAGES 2-34 and 2-35,
ELEVATION AND
              ELEVATION CODE.  
    CC 76     ELEVATION CODE.
    CC 77-78  STATE OR COUNTRY CODE.  IF THE CONTROL STATE IS
LOCATED IN THE                   UNITED STATES/CANADA, ENTER THE
CODE FROM ANNEX A FOR THE                        STATE/PROVINCE OR
TERRITORY WHICH CONTAINS THE STATION.  IF NOT,                
ENTER THE CODE FROM ANNEX A FOR THE COUNTRY WHICH CONTAINS THE     
             STATION.  SEE ANNEX A. 
    CC 79-80  STATION ORDER AND TYPE.  REFER TO PAGES 2-35 THRU
2-38, STATION                  ORDER AND TYPE AND SEE ANNEX E.




         








                                    

                                2-78
               CONTROL POINT (UTM/SPC) RECORD (*81*)

Use this record for the designation (name) and position in
Universal Transverse Mercator (UTM) coordinates or in State Plane
Coordinates (SPC) of each control point in the project.  If the
position is expressed in geodetic latitude and longitude, use the
*80* record.  The geodetic position of every horizontal control
point for which a *81* record is submitted must be provided to
serve as  either a fixed (constrained) position or as a
preliminary position in the adjustment of the horizontal control
survey project.

NOTE:  Although columns 70-75 and column 76 of this record are
currently used for recording the elevation and elevation code, NGS
may discontinue this in the near future.  NGS prefers that you use
the new *86* record for this purpose.

                            *81* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE. MUST BE *81*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  SEE PAGES 1-1, JOB
CODE AND SURVEY                 POINT NUMBERING AND 2-12,
ASSIGNMENT OF STATION SERIAL NUMBERS.
    CC 15-44  STATION NAME. MUST NOT EXCEED 30 CHARACTERS.  THE
NAME OF A                      HORIZONTAL CONTROL POINT WITH
PERIPHERAL REFERENCE MARKS AND/OR                  AZIMUTH MARKS
MUST NOT EXCEED 24 CHARACTERS TO ALLOW FOR ADDING RM               
1, RM 2, AND/OR AZ MK TO THE NAME WITHOUT EXCEEDING THE 30         
             CHARACTER LENGTH LIMIT.
    CC 45-55  UTM/SPC NORTHING (Y COORDINATE).  IN METERS
(MMMMMMMMmmm).
    CC 56-65  UTM/SPC EASTING (X COORDINATE).  IN METERS
(MMMMMMMmmm). 
    CC 66-69  UTM/SPC ZONE CODE.

NGS PREFERS THAT YOU USE THE NEW *86* RECORD FOR RECORDING THE
ELEVATION (ORTHOMETRIC HEIGHT) AND ELEVATION CODE INSTEAD OF THE
TWO DATA FIELDS THAT FOLLOW.  REFER TO PAGES 2-83 THRU 2-85.

    CC 70-75  ELEVATION. RECORD ELEVATION OF MARK ABOVE MEAN SEA
LEVEL.  IN                    METERS (MMMMmm).  ENTER THE
ELEVATION TO THE NEAREST CENTIMETER                  (cm).  IF THE
MEASUREMENT IS ONLY OBSERVED TO THE NEAREST                       
DECIMETER (dm), LEAVE CC 75 BLANK, IF OBSERVED ONLY TO THE NEAREST 
              METER (M), LEAVE CC 74-75 BLANK.  REFER TO PAGES
2-34 and 2-35,
              ELEVATION AND ELEVATION CODE.
    CC 76     ELEVATION CODE.
    CC 77-78  STATE OR COUNTRY CODE.  IF THE CONTROL STATE IS
LOCATED IN THE                   UNITED STATES/CANADA, ENTER THE
CODE FROM ANNEX A FOR THE                        STATE/PROVINCE OR
TERRITORY WHICH CONTAINS THE STATION. IF NOT,                 
ENTER THE CODE FROM ANNEX A FOR THE COUNTRY WHICH CONTAINS THE     
             STATION.  SEE ANNEX A. 
    CC 79-80  STATION ORDER AND TYPE.  REFER TO PAGES 2-35 THRU
2-38, STATION                  ORDER AND TYPE.  SEE ANNEX E.





                                2-79
              REFERENCE OR AZIMUTH MARK RECORD (*82*)

Use this record to give the name or destination of each reference
mark (RM) or azimuth mark (AZ MK).  Follow each horizontal control
point record, *80* or *81*, with as many *82* records as there are
peripheral reference marks and/or azimuth marks associated with
the horizontal control point in question.  Distance, direction
and/or angle observations to an RM or AZ MK must appear among the
*20*-series (direction) and/or the 30*-series (angle) and the      
  *50*-series (distance) observation records.  Do not submit a
*82* record for a RM or AZ MK which is being used as a horizontal
control point (i.e., when the RM or AZ MK has an adjusted geodetic
position or when the position is to be determined).  Instead,
submit a *80* or *81* record, identifying the station with a four-
digit station serial number (SSN).

Use this record in lieu of the *80* or *81* record for observed
horizontal points to which direction, angle, and/or distance
observations were made but which (1) cannot be positioned using
data of this project alone, and (2) for which a position is not
available from other sources.

For submitting unpositionable vertical control points, use the
*82* record.

                            *82* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *82*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  REFER TO PAGES 1-1
THRU 1-3, JOB                   CODE AND SURVEY POINT NUMBERING
AND 2-12 THRU 2-13, ASSIGNMENT                   OF STATION SERIAL
NUMBERS.
    CC 15-44  NAME OF RM OR AZ MK.  MUST NOT EXCEED 30 CHARACTERS. 
NORMALLY,                  THE NAME OF A RM OR AN AZ MK IS
COMPOSED BY APPENDING "RM 1",                    "RM 2", ETC. OR
"AZ MK" TO THE NAME OF THE CONTROL (PARENT)                     
STATION REFERENCED.  SEE PAGE 2-32, NAME OR DESIGNATION OF RM OR   
             AZ MK.
    CC 45-50  BLANK
   CC 51-54  CONTROL STATION (SSN). ENTER THE SSN OF THE CONTROL
   (PARENT)                 STATION FOR WHICH THE STATION
   IDENTIFIED IN CC 11-14 IS A                   REFERENCE OR
   AZIMUTH MARK.
    CC 55-80  BLANK














                                2-80

                     BENCH MARK RECORD (*83*)

NGS has discontinued the use of this record.  Effective
immediately, record this vertical control data in the Orthometric
Height, Geoid Height, Ellipsoid Height Record (*86*).  See pages
2-83 thru 2-85.


                    GEOID HEIGHT RECORD (*84*)

NGS has discontinued the use of this record.  Effective
immediately, record this data, if required, in the Orthometric
Height, Geoid Height, Ellipsoid Height Record (*86*).  See page 2-
83 thru 85.








































                                2-81
                     DEFLECTION RECORD (*85*)

Use this record to give the source and the values of the
meridional component (Xi) and/or prime-vertical component (Eta) of
the deflection of vertical.  The datum must be North American 1983
or as specified on the Datum and Ellipsoid (*13*) record.  This
record is optional.

                            *85* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE. MUST BE *85*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  HORIZONTAL CONTROL
POINT.
    CC 15-20  SOURCE. AGENCY OR ORGANIZATION WHICH DETERMINED THE
DEFLECTION.                  USE THE ABBREVIATIONS LISTED IN ANNEX
C OR THE ONE SPECIFIED ON                  THE DATA SET
IDENTIFICATION RECORD (*aa*).
    CC 21-62  COMMENT.  USE THIS SPACE TO CLARIFY THE SOURCE OF
THE DEFLECTION                 INFORMATION.
    CC 63-67  MERIDIONAL COMPONENT (Xi) OF THE DEFLECTION OF
VERTICAL.  IN                     SECONDS (XXXxx).
    CC 68     DIRECTION OF Xi.  USE CODE "N" FOR NORTH OR CODE "S"
FOR SOUTH.
    CC 69-71  SIGMA.  ESTIMATED ACCURACY (STANDARD ERROR) OF Xi.
IN SECONDS                    (Xxx).
    CC 72-76  PRIME-VERTICAL COMPONENT (Eta) OF THE DEFLECTION OF
VERTICAL.  IN                SECONDS (XXXxx).
    CC 77     DIRECTION OF Eta.  USE CODE "E" FOR EAST OR CODE "W"
FOR WEST.
    CC 78-80  SIGMA.  ESTIMATED ACCURACY (STANDARD ERROR) OF Eta. 
IN SECONDS                  (Xxx).

For a more detailed explanation of the contents of this record see
Chapter 2, pages 2-39 and 2-40, Deflection of Vertical.        






















                               2-82
 ORTHOMETRIC HEIGHT, GEOID HEIGHT, ELLIPSOID HEIGHT RECORD (*86*)

Use this record to give the values of orthometric height, geoid
height, and/or ellipsoid height of control points in this project.

For every Control Point Record (*80* or *81*), the orthometric
height, commonly referred to as the elevation, of each control
point must be provided, except for unmonumented recoverable
landmarks positioned by intersection.  For such landmarks, this
record need not be submitted.  However, when the elevation of an
unmonumented recoverable landmark is given, it should be the
orthometric height at ground level , and the height above ground
level of the point actually sighted should be entered as the
height of target on the respective observation record.

The geoid height and ellipsoid height values are optional, with
one exception.  The geoid height is required if the orthometric
height is determined from GPS observations (code G in the Table of
Orthometric Height Codes listed on the following page).  If values
for the geoid height and/or ellipsoid height are provided, then
the associated codes for each are required.

The submitting organization may leave the orthometric height Order
and Class code blank.  These fields should only be filled if the
orthometric height is adjusted and included in the National
Geodetic Survey Integrated Database (NGSIDB).

The submitting organization may leave the Orthometric Height (OHT)
Code field blank if the orthometric height was obtained from the
NGSIDB.  The Orthometric Height (OHT) NGSIDB Indicator field must
be used to say whether the orthometric height came from the NGSIDB
or not.

                            *86* FORMAT

   CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
   FROM THE
              PREVIOUS RECORD.
   CC 07-10  DATA CODE.  MUST BE *86*.
   CC 11-14  STATION SERIAL NUMBER (SSN).
   CC 15-16  BLANK
   CC 17-23  ORTHOMETRIC HEIGHT.  IN METERS (MMMMmmm).
   CC 24     ORTHOMETRIC HEIGHT CODE.  SEE FOLLOWING TABLES.
   CC 25-26  ORTHOMETRIC HEIGHT ORDER AND CLASS.  USE PUBLISHED
              VERTICAL ORDER AND CLASS, OTHERWISE LEAVE BLANK.
   CC 27     ORTHOMETRIC HEIGHT NGSIDB INDICATOR.  SEE FOLLOWING
   TABLES.
   CC 28-29  ORTHOMETRIC HEIGHT DATUM.  SEE FOLLOWING TABLES.
   CC 30-35  ORGANIZATION WHICH ESTABLISHED AND/OR MAINTAINS THE
              ORTHOMETRIC HEIGHT OF THE CONTROL POINT.  ENTER THE
              ABBREVIATION LISTED IN ANNEX C OR ON THE DATASET
              IDENTIFICATION RECORD.
   CC 36-42  GEOID HEIGHT.  ABOVE (POSITIVE) OR BELOW (NEGATIVE)
   THE
              REFERENCE ELLIPSOID.  IN METERS (MMMMmmm).
   CC 43     GEOID HEIGHT CODE.  SEE FOLLOWING TABLES.
   CC 44-45  BLANK.


                               2-83
   CC 46-52  ELLIPSOID HEIGHT.  IN METERS (MMMMmmm).
   CC 53     ELLIPSOID HEIGHT CODE.  SEE FOLLOWING TABLES.
   CC 54-55  ELLIPSOID HEIGHT ORDER AND CLASS.  SEE ANNEX G.
   CC 56     ELLIPSOID HEIGHT DATUM.
   CC 57-80  COMMENTS.


             ORTHOMETRIC HEIGHT (OHT) NGSIDB INDICATOR

   CODE   EXPLANATION

    Y     OHT OBTAINED FROM THE NGSIDB.
    N     OHT IS NOT IN THE NGSIDB.


              TABLE OF ORTHOMETRIC HEIGHT (OHT) CODES

   CODE   EXPLANATION

    A     OHT ESTABLISHED USING FGCS LEVELING SPECIFICATIONS AND
          PROCEDURES, ADJUSTED HEIGHT DETERMINED USING NGS VERTICAL
             NETWORK BRANCH PROCEDURES, LEVELING DATA IS IN THE
          NGSIDB.
    B     OHT ESTABLISHED USING FGCS LEVELING SPECIFICATIONS AND
           PROCEDURES, ADJUSTED HEIGHT DETERMINED USING NGS
VERTICAL
           NETWORK BRANCH PROCEDURES, LEVELING DATA IS NOT IN THE
           NGSIDB. (USGS, COE, SOME STATE DOT DATA.)
    C     OHT ESTABLISHED USING FGCS LEVELING SPECIFICATIONS AND
           PROCEDURES, ADJUSTED HEIGHT IS 'POSTED'.  SEE
EXPLANATION
           IN THE FOOTNOTE (*) BELOW.
    H     OHT ESTABLISHED USING FGCS LEVELING SPECIFICATIONS AND
           PROCEDURES EXCEPT FOR THE TWO-MARK LEVELING TIE
           REQUIREMENT.  (HORIZONTAL FIELD PARTY LEVEL TIES, SOME
           STATE DOTS, SOME GPS LEVEL TIES.)
    L     OHT ESTABLISHED USING LEVELING RESET SPECIFICATIONS AND
           PROCEDURES.
    F     OHT ESTABLISHED BY FLY-LEVELING.
    T     OHT ESTABLISHED BY LEVELING BETWEEN CONTROL POINTS WHICH
           ARE NOT BENCH MARKS.
    R     OHT ESTABLISHED BY RECIPROCAL VERTICAL ANGLES.
    V     OHT ESTABLISHED BY NON-RECIPROCAL VERTICAL ANGLES.
    P     OHT ESTABLISHED BY PHOTOGRAMMETRY.
    M     OHT ESTABLISHED BY SCALING FROM A CONTOURED MAP.
    G     OHT ESTABLISHED BY GPS OBSERVATIONS.
    D     OHT ESTABLISHED BY DATUM TRANSFORMATIONS.


* DATA FOR LEVEL LINES CONTAINING 'POSTED' BENCH MARKS WERE
PURPOSELY NOT
  INCLUDED IN THE NAVD88 GENERAL ADJUSTMENT.  SUBSEQUENTLY, THESE
DATA WERE
  ADJUSTED TO NAVD88 BY FORCING THEM TO FIT THE EXISTING NAVD88
GENERAL
  ADJUSTMENT HEIGHTS.



                               2-84
             TABLE OF ORTHOMETRIC HEIGHT (OHT) DATUMS

   CODE   EXPLANATION

    29    NATIONAL GEODETIC VERTICAL DATUM OF 1929
    88    NORTH AMERICAN VERTICAL DATUM OF 1988
    55    INTERNATIONAL GREAT LAKES DATUM OF 1955
    85    INTERNATIONAL GREAT LAKES DATUM OF 1985
    00    ANY OTHER DATUM.  SPECIFY IN COMMENTS.


                 TABLE OF GEOID HEIGHT (GHT) CODES

   CODE   EXPLANATION

    P     OSU78 GEOID MODEL
    Q     OSU86F GEOID MODEL
    B     OSU89B GEOID MODEL
    C     GEOID90 GEOID MODEL
    D     GEOID93 GEOID MODEL


               TABLE OF ELLIPSOID HEIGHT (EHT) CODES

   CODE   EXPLANATION

    A     EHT DETERMINED BY GPS IN A HIGH PRECISION GEODETIC
   NETWORK
           OR TIED TO A HIGH PRECISION GEODETIC NETWORK (HPGN).
    B     EHT DETERMINED BY GPS NOT TIED TO A HPGN.
    C     EHT DETERMINED BY ADDING A GEOID HEIGHT TO AN
   ORTHOMETRIC
           HEIGHT WITH AN OHT CODE OF A, B, C, F, H, OR L.
    D     EHT DETERMINED BY ADDING A GEOID HEIGHT TO AN
   ORTHOMETRIC
           HEIGHT WITH AN OHT CODE OF T OR R.
    E     EHT DETERMINED BY ADDING A GEOID HEIGHT TO AN
   ORTHOMETRIC
           HEIGHT WITH AN OHT CODE OF V, M, P, OR D.




              TABLE OF ELLIPSOID HEIGHT (EHT) DATUMS

   CODE   EXPLANATION

    A     NORTH AMERICAN DATUM OF 1983
    B     INTERNATIONAL TERRESTRIAL REFERENCE FRAME OF 1989
    C     NATIONAL EARTH ORIENTATION SERVICE (NEOS ANNUAL
          REPORT FOR 1990)
    Z     ANY OTHER DATUM.  SPECIFY IN COMMENTS.





                               2-85
                    FIXED CONTROL RECORD (*90*)

Use this record to identify previously established horizontal
control points contained in the NGS Data Base, from which and/or
to which horizontal control was extended in this project.  Two or
more fixed control points are expected in a horizontal control
survey project.  But, if only one previously established
horizontal control point is identified as fixed, scale and
orientation must be provided by *50*-series (distance) and *60*-
series (azimuth) records.

                            *90* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.  INCREMENT BY 10
FROM THE                     PREVIOUS RECORD.
    CC 07-10  DATA CODE.  MUST BE *90*.
    CC 11-14  STATION SERIAL NUMBER (SSN).  ESTABLISHED HORIZONTAL
CONTROL                     POINT.
    CC 15-20  SOURCE.  AGENCY OR ORGANIZATION WHICH DETERMINED THE
COORDINATES.                USE THE ABBREVIATIONS LISTED IN ANNEX
C OR THE ONE ON THE DATA SET                IDENTIFICATION RECORD
(*aa*).
    CC 21-74  COMMENT.  IF THE NAME OF THE ORGANIZATION WHICH
DETERMINED THE                   FIXED COORDINATES DOES NOT APPEAR
IN ANNEX C OR ON THE DATA SET                  IDENTIFICATION
RECORD, GIVE THE FULL NAME OF THE ORGANIZATION IN                
THIS SPACE.  OTHERWISE, USE THIS SPACE FOR COMMENTS PERTINENT TO   
             THE CONTROL POINT.
    CC 75-80  NGS CONTROL NUMBER. LEAVE BLANK UNLESS THIS NUMBER
IS OBTAINED                   FROM THE NGS.  CODE THE LETTER "G"
IN CC 75.       



























                               2-86
                DATA SET TERMINATION RECORD (*aa*)

The last record in a Horizontal Observation Data set must be the
Data Set
Termination Record.  The job code used in this record must be
identical to the job code in the Data Set Identification Record,
the first record in the Horizontal Observation Data Set (HZTL
OBS), and identical to the job code used in both the Data Set
Identification Record and the Data Set Termination Record of the
Geodetic Control Point Descriptive Data Set (GEOD DESC).  This
record is required.        
                                  *aa* FORMAT

    CC 01-06  SEQUENCE NUMBER.  RIGHT JUSTIFIED.                   
            
    CC 07-10  JOB CODE.  MUST BE *aa*.  THE SYMBOL "aa" DENOTES
THE                            TWO-CHARACTER JOB CODE ASSIGNED BY
THE SUBMITTING ORGANIZATION.
    CC 11-80  BLANK                                

For a more detailed explanation of the contents of the record see
Chapter 1, page 1-1, JOB CODE AND POINT NUMBERING and Chapter 2,
pages 2-1 thru 2-3, HZTL OBS DATA SET RECORDS.


































                               2-87
                   FORMAT DIAGRAMS APPEAR ON THE
                  REMAINING PAGES OF THIS CHAPTER



















































                               2-88
HORIZONTALOBSERVATIONDATASETRECORDS

 
 DATA SET IDENTIFICATION RECORD
 
 1         6   7     10 11     14 15     18 19         24   25                               
         46
Ŀ Ŀ Ŀ Ŀ Ŀ  
Ŀ
      

  SEQUENCE       JOB      DATA      DATA    ORGANIZATION            SUBMITTING ORGANIZATION
NAME
   NUMBER        CODE     CLASS     TYPE    ABBREVIATION                        
                                            (See Annex C)
 
            47                                        66     67          72   73            
80
             Ŀ     Ŀ  
Ŀ
                    

              SUBMITTING ORGANIZATION NAME CONTINUED             BLANK         Y Y Y Y M M D
D                                                                                            
     DATE CREATED                   
--------------------------------------------------------------------------------------------
-------------

           *10* PROJECT TITLE RECORD
 
 1         6    7    10  11                                                                  
45
Ŀ  Ŀ
Ŀ
  

  SEQUENCE       DATA                               PROJECT TITLE
   NUMBER        CODE    46                                                                  
80
 (INC BY 10)            
Ŀ
                        

                                            PROJECT TITLE CONTINUED
--------------------------------------------------------------------------------------------
-------------
 
          *11* PROJECT TITLE CONTINUATION RECORD (OPTIONAL)

 1         6    7     10 11                                                                  
45
Ŀ  Ŀ
Ŀ
  

  SEQUENCE       DATA                          PROJECT TITLE CONTINUATION
   NUMBER        CODE    46                                                                  
80
 (INC BY 10)            
Ŀ
                        

                                               PROJECT TITLE CONTINUATION
 
                                            2-89
          *12* PROJECT INFORMATION RECORD
 
 1         6   7     10 11         16 17         22     23   25    26                        
        43
Ŀ Ŀ Ŀ Ŀ     Ŀ   
Ŀ
           

  SEQUENCE      DATA     Y Y Y Y M M   Y Y Y Y M M      INITIALS                    FULL
NAME
   NUMBER       CODE     DATE FIELD     DATE FIELD       C OF P                  CHIEF OF
PARTY
 (INC BY 10)             OBS BEGAN      OBS ENDED                                    (FIRST)
 
 44   46  47                                 64  65                   75   76    77         
79
 Ŀ  Ŀ  Ŀ   Ŀ   Ŀ      
Ŀ
                 

 INITIALS               FULL NAME                        BLANK            TYPE   STATE/  
SURVEY ORDER
  C OF P             CHIEF OF PARTY                                      SURVEY  COUNTRY  
AND CLASS
                        (SECOND)                                                 CODE
 
--------------------------------------------------------------------------------------------
-------------
 
           *13* GEODETIC DATUM AND ELLIPSOID RECORD
 
 1         6   7     10 11                                             34 35                 
         50
Ŀ Ŀ Ŀ
Ŀ
  

  SEQUENCE      DATA          DATUM NAME                                       ELLIPSOID
NAME
   NUMBER       CODE
 (INC BY 10)
 
51           57   58   60  61   63   64           70    71           77   78   80
Ŀ   Ŀ  Ŀ   Ŀ    Ŀ   Ŀ
 .    .      . 
 M M M M M M M     m m m    X X X     x x x x x x x      M M M M M M M     m m m
    SEMI-MAJOR AXIS           INVERSE FLATTENING            SEMI-MINOR AXIS
       (METERS)                     (1/f)                      (METERS)
 
 
 
 
 



                                            2-90
          *20* HORIZONTAL DIRECTION SET RECORD
 
 1         6   7     10 11     14 15    17         22    23       25       29   30   32   
33   35
Ŀ Ŀ Ŀ Ŀ Ŀ    Ŀ    Ŀ   Ŀ   
Ŀ
                  

  SEQUENCE      DATA       SSN     SET  FIELD RECORD     NO. OF      WEATHER    OBSERVER    
JSIN
   NUMBER       CODE      INST.    NO.    BOOK NO.      TARGETS      CODE       INITIALS     

 (INC BY 10)                                            SIGHTED
 
36       39 40         45 46     49   50    51     54  55       58    59       60         63
Ŀ Ŀ Ŀ Ŀ   Ŀ   Ŀ  Ŀ Ŀ    Ŀ      Ŀ   Ŀ
.          .             
 M M   m m   Y Y M M D D   H H M M    ZONE     SSN      M M   m m   VISIBILITY  NO.     S S
    H.I.     DATE OF OBS.   TIME      CODE   TARGET        H.T.       CODE      OF   
REJECTION
  (METERS)                                               (METERS)               REP.   LIMIT
                                                                                     
(SECONDS)

64           70  71        73        76     77        80
Ŀ  Ŀ     Ŀ  Ŀ     Ŀ  Ŀ
.      .      . 
 D D D M M S S    s s       S S    s s       S S    s s
 INITIAL DIRECTION          INT. SIGMA       EXT. SIGMA
                             (SECONDS)        (SECONDS)
--------------------------------------------------------------------------------------------
-------------
 
          *21* HORIZONTAL DIRECTION COMMENT RECORD (OPTIONAL)
 
 1         6   7     10 11                                                                  
45            
Ŀ Ŀ
Ŀ          
 
          
  SEQUENCE       DATA              COMMENT(S)
   NUMBER        CODE   46                                                                  
80
 (INC BY 10)           
Ŀ
                       

                                   COMMENT(S) CONTINUED
 
 
 
 


                                            2-91
          *22* HORIZONTAL DIRECTION RECORD
 
 1         6   7     10 11     14 15    17                                                   
   45
Ŀ Ŀ Ŀ Ŀ
Ŀ
   

  SEQUENCE      DATA       SSN     SET                      BLANK
   NUMBER       CODE      INST.    NO.
 (INC BY 10)
                                                                                 
46     49    50    51     54  55        58       59       60      62      64           70 
71
Ŀ    Ŀ   Ŀ  Ŀ  Ŀ       Ŀ      Ŀ   Ŀ   Ŀ 
Ŀ
         .                    .

 H H M M    ZONE      SSN      M M    m m    VISIBILITY    NO.     S S     D D D M M S S   
s s
  TIME      CODE    TARGET        H.T.          CODE       OF      REJ           CLOCKWISE
                                (METERS)                   REP.   LIMIT          DIRECTION
 
              73        76        77        80
              Ŀ  Ŀ        Ŀ  Ŀ
              .         . 
               S S    s s          S S    s s
               INT. SIGMA          EXT. SIGMA
                (SECONDS)           (SECONDS)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  




                                            2-92
          *25* GPS OCCUPATION HEADER RECORD

 1         6   7     10 11     14 15                 24   25   27     28   30     31 32
Ŀ Ŀ Ŀ Ŀ   Ŀ     Ŀ     Ŀ
                
  SEQUENCE      DATA       SSN         DATA MEDIA        OBSERVER'S  INSTRUMENT   CABLE
   NUMBER       CODE                   IDENTIFIER        INITIALS      NUMBER     LENGTH
 (INC BY 10)                      

33                                                                                           
 80

Ŀ


                                      BLANK
--------------------------------------------------------------------------------------------
------------------ 
          *26* GPS OCCUPATION COMMENT RECORD (OPTIONAL)

 1         6   7    10  11                                                                  
45
Ŀ Ŀ
Ŀ
 

  SEQUENCE      DATA                              COMMENT
   NUMBER       CODE    46                                                                  
80
 (INC BY 10)           
Ŀ
                       

                                            CONTINUED COMMENT
--------------------------------------------------------------------------------------------
------------------
          *27* GPS OCCUPATION MEASUREMENT RECORD

 1         6   7    10  11    14  15        20   21    24    25    27  29   30      33    
34       35       38
Ŀ Ŀ Ŀ Ŀ  Ŀ   Ŀ Ŀ  Ŀ Ŀ   
Ŀ      Ŀ Ŀ
        .  .   
      .
  SEQUENCE      DATA       SSN     Y Y M M D D    H H M M     X X   x x x    X X X   x   DRY
BULB    X X X   x
   NUMBER       CODE               OBSERVATION  OBSERVATION  ANTENNA HEIGHT  DRY BULB  
TEMPERATURE  WET BULB
 (INC BY 10)                          DATE         TIME         (METERS)    TEMPERATURE   
CODE     TEMPERATURE

   39       40    42  43        47     49       51       55  56                              
               80
   Ŀ      Ŀ Ŀ Ŀ Ŀ  Ŀ    Ŀ 
Ŀ
         . .       

 WET BULB    X X   x   X X X X   x x  PRESSURE    WEATHER                        BLANK
TEMPERATURE  RELATIVE   BAROMETRIC      CODE       CODE
   CODE      HUMIDITY    PRESSURE
 
                                            2-93
          *28* GPS CLOCK SYNCHRONIZATION RECORD

 1         6   7     10 11         16      17     20     21   23     24   26  27       31 32 
       36
Ŀ Ŀ Ŀ      Ŀ     Ŀ     Ŀ  Ŀ
Ŀ Ŀ
                    
.
  SEQUENCE      DATA     Y Y M M D D        H H M M     INSTRUMENT  INSTRUMENT   BLANK     X
X X   x x
   NUMBER       CODE   SYNCHRONIZATION  SYNCHRONIZATION   NUMBER      NUMBER            
TIMING DIFFERENCE
 (INC BY 10)                DATE             TIME           A           B                
(MICROSECONDS)

     37        38   40  41                                                                   
         80
     Ŀ       Ŀ 
Ŀ
             

INTEGER TIME  OBSERVER'S                                  BLANK
SECOND SYNCH   INITIALS
  Y OR N

--------------------------------------------------------------------------------------------
-------------

          *29*  GPS CLOCK SYNCHRONIZATION COMMENT RECORD

 1         6   7     10 11                                                                  
45
Ŀ Ŀ
Ŀ
 

  SEQUENCE      DATA                              COMMENT                                   
   NUMBER       CODE                                                                        
 (INC BY 10)                                                                                

 46                                                                   80                     

 Ŀ                    
 
                  CONTINUED COMMENT 










                                            2-94
          *30* HORIZONTAL ANGLE SET RECORD
 
 1         6   7     10 11     14 15    17         22     23     25       29  30   32     33 
 35
Ŀ Ŀ Ŀ Ŀ Ŀ     Ŀ  Ŀ  Ŀ    
Ŀ
                 

  SEQUENCE      DATA       SSN     SET   FIELD RECORD     NO. OF   WEATHER    OBSERVER     
JSIN
   NUMBER       CODE      INST.    NO.   BOOK NUMBER      ANGLES     CODE     INITIALS      
 (INC BY 10)                                             OBSERVED
                                                                              
36        39  40         45  46     49  50  51     54  55        58      59      60         
62  
Ŀ  Ŀ  Ŀ  Ŀ  Ŀ Ŀ  Ŀ  Ŀ      Ŀ     Ŀ      
Ŀ
.          .                  

 M M    m m    Y Y M M D D    H H M M  ZONE    SSN      M M    m m   VISIBILITY  NO. OF      
S S
    H.I.       DATE OF OBS.    TIME    CODE   FIRST        H.T          CODE     REPL. 
REJECTION LIMIT
  (METERS)                                    TARGET     (METERS)                         
(SECONDS)
 
64               71  72     75  76       79        80
Ŀ Ŀ  Ŀ  Ŀ Ŀ       Ŀ
.    .       
 D D D M M S S   s      SSN      M M   m m     VISIBILITY
  CLOCKWISE ANGLE      SECOND       H.T.          CODE
                       TARGET     (METERS)
 
--------------------------------------------------------------------------------------------
-------------
 
           *31* HORIZONTAL ANGLE COMMENT RECORD (OPTIONAL)
 
 1         6   7     10 11                                                                  
45            
Ŀ Ŀ
Ŀ          
 
          
  SEQUENCE      DATA                 COMMENT(S)
   NUMBER       CODE    46                                                                  
80      
 (INC BY 10)           
Ŀ 
                       

                                     COMMENT(S) CONTINUED 
 
 
 
 


                                            2-95
           *32* HORIZONTAL ANGLE RECORD
 
 1         6   7     10 11     14 15    17                          45 46     49 50   51    
54
Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ 
Ŀ
       

  SEQUENCE      DATA       SSN     SET               BLANK              H H M M  ZONE    SSN

   NUMBER       CODE      INST.    NO.                                    TIME   CODE  
FIRST 
 (INC BY 10)                                                                           
TARGET
 
55       58    59      60     62       64               71  72     75 76       79    80
Ŀ Ŀ    Ŀ     Ŀ  Ŀ    Ŀ Ŀ  Ŀ Ŀ Ŀ    Ŀ
.               .   .    
 M M   m m  VISIBILITY  NO.    S S      D D D M M S S   s      SSN     M M   m m  
VISIBILITY
    H.T.      CODE      OF  REJECTION    CLOCKWISE ANGLE      SECOND      H.T.       CODE
  (METERS)              REP.  LIMIT                           TARGET    (METERS)
                            (SECONDS)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

                                            2-96
          *40* VERTICAL ANGLE SET RECORD
 
 1         6   7     10 11     14 15    17         22  23      25       29  30   32  33   35
36       39
Ŀ Ŀ Ŀ Ŀ Ŀ  Ŀ   Ŀ  Ŀ  Ŀ
Ŀ Ŀ
             
.
  SEQUENCE      DATA       SSN     SET  FIELD RECORD   NO. OF    WEATHER    OBSERVER   JSIN  
M M   m m
   NUMBER       CODE      INST.    NO.  BOOK NUMBER    VAs/ZDs     CODE     INITIALS         
   H.I.
 (INC BY 10)                                           OBSERVED                              
(METERS)
 
40         45 46     49   50   51     54   55       58     59      60     62     64          
    71
Ŀ Ŀ   Ŀ  Ŀ   Ŀ Ŀ     Ŀ     Ŀ  Ŀ 
Ŀ Ŀ
         .             
.
 Y Y M M D D   H H M M   ZONE     SSN       M M   m m   VISIBILITY  NO.    S S    D D D M M
S S   s
    DATE         TIME    CODE    TARGET        H.T.        CODE     OF     REJ.      VA OR
ZD
                                             (METERS)               REP.  LIMIT   
OBSERVATION
                                                                        (SECONDS)
   72    73       76  77       80
   Ŀ   Ŀ Ŀ  Ŀ Ŀ
      .  .
  ANGLE   S S   s s    S S   s s
  CODE    INT. SIGMA   EXT. SIGMA
          (SECONDS)   (SECONDS/KM)
 
--------------------------------------------------------------------------------------------
-------------
 
 
          *41* VERTICAL ANGLE COMMENT RECORD (OPTIONAL)
 
 1         6   7     10 11                                                                  
45           
Ŀ Ŀ
Ŀ          
 
          
  SEQUENCE      DATA                COMMENT(S)
   NUMBER       CODE    46                                                                  
80
 (INC BY 10)           
Ŀ
                       

                                    COMMENT(S) CONTINUED 
 
 
 
 

                                            2-97
       *42* VERTICAL ANGLE RECORD
 
 1         6   7     10 11     14 15    17                          45 46     49  50   51    
54
Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ  Ŀ 
Ŀ
        

  SEQUENCE      DATA       SSN     SET               BLANK              H H M M   ZONE   
SSN
   NUMBER       CODE      INST.    NO.                                    TIME    CODE  
TARGET
 (INC BY 10)
 
55       58      59        60       62       64               71  72   73       76   77      
80
Ŀ Ŀ      Ŀ       Ŀ    Ŀ    Ŀ Ŀ  Ŀ  Ŀ Ŀ   Ŀ
Ŀ
.                     .    .  
.
 M M   m m   VISIBILITY     NO.      S S      D D D M M S S   s  ANGLE  S S   s s     S S  
s s
    H.T.        CODE        OF    REJECTION       VA/ZD           CODE  INT. SIGMA    EXT.
SIGMA
 (METERS)                   REP.    LIMIT      OBSERVATION              (SECONDS)  
(SECONDS/KM)
                                  (SECONDS)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


 


                                            2-98
           *45* OBSERVED DIFFERENCE OF ELEVATION RECORD

 
 1         6   7     10 11     14 15 16 17         22  23 24 25       29 30   32  33   35 36 
 38   39
Ŀ Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ Ŀ  Ŀ
Ŀ   Ŀ
          
   
  SEQUENCE      DATA       SSN    BLANK  FIELD RECORD  BLANK   WEATHER   OBSERVER  JSIN   
NO. OF  BLANK
   NUMBER       CODE      INST.          BOOK NUMBER             CODE    INITIALS         
SETUPS
 (INC BY 10)
 
40         45 46     49  50   51     54 55     58     59      60 61  62 63  64               
 72
Ŀ Ŀ  Ŀ  Ŀ Ŀ     Ŀ     Ŀ  Ŀ  Ŀ
Ŀ  
                   
.  
 Y Y M M D D   H H M M  ZONE     SSN     BLANK     VISIBILITY  NO.   BLANK   M M M M M   m m
m m 
 DATE OF OBS.   TIME    CODE   TARGET                 CODE     OF            DIFF. OF
ELEVATION
                                                               REP.              (METERS)
      73       76       77       80
      Ŀ Ŀ       Ŀ Ŀ
      .       .
       X X   x x         X X   x x
       LEVELING          LENGTH OF
        SIGMA             SECTION
    (MILLIMETERS)       (KILOMETERS)
 
--------------------------------------------------------------------------------------------
-------------
 
          *46* DIFFERENCE OF ELEVATION COMMENT RECORD (OPTIONAL)
 
 1         6   7     10 11                                                                   
         40
Ŀ Ŀ
Ŀ
 

  SEQUENCE      DATA                                COMMENT(S)
   NUMBER       CODE
 (INC BY 10)
                        41                                                                   
         80    
                       
Ŀ
                       

                                                    COMMENT(S) CONTINUED



                                            2-99
          *47* OBSERVED DIFFERENCE OF ELEVATION CONTINUATION RECORD
 
 1         6   7     10 11     14 15                                                         
 45          
Ŀ Ŀ Ŀ
Ŀ              
          
  SEQUENCE      DATA       SSN                                BLANK               
   NUMBER       CODE      INST.                                                        
 (INC BY 10)                                                       

              46               54   55   57    58         63 64                              
 80
              Ŀ   Ŀ    Ŀ
Ŀ
                     
         
                     BLANK           JSIN        OBSERVING                  BLANK
                                   LEVEL ROD    ORGANIZATION
                                                ABBREVIATION




























                                            2-100
          *50* TAPED DISTANCE RECORD

 1         6   7     10 11     14 15       19 20   22 23   25  26       29   30         34
35         40
Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ   Ŀ Ŀ
Ŀ
       .   .

  SEQUENCE      DATA       SSN     WEATHER   OBSERVER   JSIN    M M   m m     M M M M  m   
Y Y M M D D
   NUMBER       CODE      INST.     CODE     INITIALS          TAPE SUPPORT  STATION ELEV. 
DATE OF OBS.     
 (INC BY 10)                                                  HEIGHT (METERS)   (METERS)     
   

41     44  45   46     49 50       53  54         58    59      60 61   62 63    64          
      72         Ŀ  Ŀ  Ŀ Ŀ Ŀ  Ŀ Ŀ    Ŀ     Ŀ  
Ŀ    Ŀ Ŀ
     .  .               
.
 H H M M  ZONE     SSN     M M   m m    M M M   m m  VISIBILITY  NO.     X X      M M M M M  
m m m m 
  TIME    CODE   TARGET   TAPE SUPPORT   ELEVATION      CODE     OF   REJECTION    
CORRECTED TAPED   
                         HEIGHT (METERS) DIFFERENCE              REP.   LIMIT         
DISTANCE      
                                          (METERS)                       (mm)         
(METERS)
73      74     76    77       80                                                             
                 Ŀ     Ŀ Ŀ    Ŀ Ŀ
     .    .
DIST.    X X   x      X X X   x
CODE   INT. SIGMA    EXT. SIGMA
          (mm)         (ppm)           
--------------------------------------------------------------------------------------------
-------------
          *51* UNREDUCED DISTANCE RECORD
 
 1         6   7     10 11     14 15       19 20   22 23   25 26       29 30     34  35      
  40
Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ 
Ŀ
      .  

  SEQUENCE      DATA       SSN      WEATHER  OBSERVER  JSIN    M M   m m    BLANK     Y Y M
M D D
   NUMBER       CODE      INST.      CODE    INITIALS             H.I.                DATE
OF OBS.
 (INC BY 10)                                                    (METERS)
 
41     44  45   46     49   50       53  54     58     59      60 61   62 63    64           
     72      
Ŀ  Ŀ  Ŀ   Ŀ Ŀ  Ŀ     Ŀ     Ŀ   Ŀ    Ŀ
Ŀ  
       .                  
.       
 H H M M  ZONE     SSN       M M   m m     BLANK    VISIBILITY  NO.     X X      M M M M M  
m m m m   
  TIME    CODE    TARGET        H.T.                   CODE     OF   REJECTION  CORRECTED
SLANT RANGE      
                                                                REP.   LIMIT         
DISTANCE
73      74     76    77       80                                       (mm)          
(METERS)
Ŀ     Ŀ Ŀ    Ŀ Ŀ
     .    .
DIST.    X X   x      X X X   x
CODE   INT. SIGMA    EXT. SIGMA
         (mm)          (ppm)
                                            2-101
          *52* REDUCED DISTANCE RECORD
 
 1         6   7     10 11     14 15       19 20   22 23   25 26       29  30         34  35 
       40
Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ 
Ŀ
      .  . 

  SEQUENCE      DATA       SSN     WEATHER   OBSERVER   JSIN   M M M   m    M M M M   m    Y
Y M M D D
   NUMBER       CODE      INST.     CODE     INITIALS            G.H.       MARK ELEV.    
DATE OF OBS.
 (INC BY 10)                                                   (METERS)      (METERS)

41     44  45   46     49 50       53 54         58     59      60 61   62 63   64           
     72     
Ŀ  Ŀ  Ŀ Ŀ Ŀ Ŀ Ŀ     Ŀ     Ŀ   Ŀ   Ŀ
Ŀ               . .            
   .       
 H H M M  ZONE     SSN     M M M   m   M M M M   m   VISIBILITY  NO.     X X     M M M M M  
m m m m              TIME    CODE    TARGET     G.H.      MARK ELEV.       CODE     OF  
REJECTION   REDUCED DISTANCE                                         (METERS)    (METERS)    
             REP.   LIMIT         (METERS)
                                                                         (mm)
73      74     76    77       80                                                     
Ŀ     Ŀ Ŀ    Ŀ Ŀ                                                 
     .    .
DIST     X X   x      X X X   x
CODE    INT. SIGMA    EXT. SIGMA
          (mm)          (ppm) 
--------------------------------------------------------------------------------------------
------------- 
          *53* UNREDUCED LONG LINE RECORD
 
 1         6   7     10 11     14 15                22  23   25 26       29 30       34  35  
      40
Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ Ŀ Ŀ 
Ŀ
      .  

  SEQUENCE      DATA       SSN          BLANK            JSIN    M M   m m    BLANK       Y
Y M M D D
   NUMBER       CODE      INST.                                     H.I.                 
DATE OF OBS.
 (INC BY 10)                                                      (METERS)

41     44  45   46     49 50       53  54     58    59 60 61     63     64                  
73   74
Ŀ  Ŀ  Ŀ Ŀ Ŀ  Ŀ    Ŀ Ŀ Ŀ     Ŀ
Ŀ   Ŀ
     .       .    
.   
 H H M M  ZONE     SSN     M M   m m     BLANK       NO.   M M   m       M M M M M M M   m m
m    DIST
  TIME    CODE    TARGET      H.T.                   OF   REJECTION     CORRECTED SPATIAL
CHORD   CODE
                            (METERS)                 REP.   LIMIT              DISTANCE
75     77   78     80                                      (METERS)            (METERS)
Ŀ Ŀ   Ŀ Ŀ
.   .
 X   x x     X   x x 
INT. SIGMA  EXT.SIGMA
  (mm)        (ppm)
                                            2-102

          *54* REDUCED LONG LINE RECORD
 
 1         6   7     10 11     14 15                22  23   25 26       29 30         34 35 
       40
Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ Ŀ Ŀ Ŀ
Ŀ
      . .

  SEQUENCE      DATA       SSN           BLANK           JSIN    M M M   m   M M M M   m   Y
Y M M D D
   NUMBER       CODE      INST.                                    G.H.       MARK ELEV.  
DATE OF OBS.
 (INC BY 10)                                                     (METERS)      (METERS)      
    

41         45   46     49  50       53 54         58  59 60  61     63  64                  
73   74
Ŀ  Ŀ  Ŀ  Ŀ Ŀ Ŀ Ŀ  Ŀ  Ŀ Ŀ  Ŀ
Ŀ   Ŀ
      . .    . 
.   
 H H M M  ZONE     SSN      M M M   m   M M M M   m    NO.    M M   m    M M M M M M M   m m
m    DIST
  TIME    CODE    TARGET      G.H.      MARK ELEV.     OF    REJECTION     REDUCED DISTANCE  
    CODE
                            (METERS)     (METERS)      REP.    LIMIT           (METERS)
                                                              (METERS)
       75     77   78     80
       Ŀ Ŀ   Ŀ Ŀ
       .   .
        M   m m     M   m m
       INT. SIGMA   EXT.SIGMA
         (mm)         (ppm)
 
--------------------------------------------------------------------------------------------
-------------

          *55* DISTANCE COMMENT RECORD (OPTIONAL)
 
 1         6   7     10 11                                                                   
         40
Ŀ Ŀ
Ŀ
 

  SEQUENCE      DATA                               COMMENT(S)
   NUMBER       CODE
 (INC BY 10)
                        41                                                                   
         80    
                       
Ŀ
                       

                                                   COMMENT(S) CONTINUED
 
 

                                            2-103
         *60* ASTRONOMIC AZIMUTH / LAPLACE RECORD
 
 1         6   7     10 11     14 15       18    19       20    21       29 30   32  33   35
36       39
Ŀ Ŀ Ŀ Ŀ Ŀ    Ŀ      Ŀ   Ŀ Ŀ  Ŀ
Ŀ Ŀ
   .                
.
  SEQUENCE      DATA       SSN     S S S   s     DIR..    COMP.    BLANK    OBSERVER   JSIN  
M M   m m
   NUMBER       CODE      INST.      ETA        OF ETA    CODE              INITIALS         
   H.I.         
 (INC BY 10)                      (SECONDS)    (E OR W) (A or L)                             
 (METERS)
 
40         45 46     49  50   51     54 55       58    59      60 61    62 63  64            
  71  72
Ŀ Ŀ  Ŀ  Ŀ Ŀ Ŀ    Ŀ     Ŀ    Ŀ 
Ŀ Ŀ  Ŀ
      .              
.  
 Y Y M M D D   H H M M   ZONE    SSN     M M   m m  VISIBILITY  NO.      S S    D D D M M S
S   s  ORIG.
 DATE OF OBS.   TIME     CODE   TARGET      H.T.       CODE     OF    REJECTION     AZIMUTH  
     OF AZ.
                                          (METERS)              REP.    LIMIT       OBSERVED 
     (N/S)
         73       76     77       80                                  (SECONDS)
         Ŀ Ŀ     Ŀ Ŀ
         .     .
          S S   s s       S S   s s
         INT. SIGMA      EXT. SIGMA
          (SECONDS)       (SECONDS)

--------------------------------------------------------------------------------------------
-------------

          *61* GEODETIC AZIMUTH RECORD
 
 1         6   7     10 11     14  15                                   50  51     54 55     
         63
Ŀ Ŀ Ŀ  Ŀ Ŀ
Ŀ
     

  SEQUENCE      DATA       SSN                        BLANK                    SSN          
BLANK
   NUMBER       CODE      INST.                                               TARGET
 (INC BY 10)

64               71    72     73             80
Ŀ Ŀ    Ŀ    Ŀ
.        
 D D D M M S S   s    ORIG.        BLANK
   GEODETIC           OF AZ.
    AZIMUTH           (N/S)
 
 
                                          2-104   

           *70* INSTRUMENT RECORD
 
 1         6   7     10  11   13  14   16    17       20   21 22 23                          
      40
Ŀ Ŀ  Ŀ  Ŀ    Ŀ Ŀ   Ŀ
Ŀ
         .   

  SEQUENCE      DATA      JSIN   EQUIPMENT    X X   x x    UNITS       INSTRUMENT
MANUFACTURER
   NUMBER       CODE               CODE      INSTRUMENT
 (INC BY 10)                                 RESOLUTION

41                                         62 63             70 71                 80
Ŀ Ŀ Ŀ
  
      TYPE OF INSTRUMENT OR TRADE NAME            MODEL OF            SERIAL 
                                                 INSTRUMENT           NUMBER
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

                                            2-105

          *80* CONTROL POINT RECORD
 
 1         6    7     10  11     14    15                                                    
    44
Ŀ  Ŀ  Ŀ   
Ŀ  
       
     
  SEQUENCE       DATA       SSN                               STATION  NAME                  
                     NUMBER        CODE                                                      
            
 (INC BY 10)                                                        Use *86* Record  Ŀ    
      
                                                                                       
45                     55  56    57                       68  69   70           75  76  
77 78  79   80
Ŀ Ŀ  Ŀ   Ŀ Ŀ  Ŀ   Ŀ Ŀ  Ŀ  
Ŀ  Ŀ  Ŀ     .     .    
.                D D M M S S   s s s s s   DIR.   D D D M M S S  
s s s s s   DIR.   M M M M   m m   ELEV. STATE  STA. STA.
         LATITUDE         OF LAT.          LONGITUDE        OF LONG.    ELEVATION    CODE  
CODE ORDER TYPE
                          (N/S)                              (E/W)      (METERS)      

--------------------------------------------------------------------------------------------
-----------------

          *81* CONTROL POINT RECORD (SPC/UTM)

 1         6    7     10  11     14    15                                                    
    44
Ŀ  Ŀ  Ŀ   
Ŀ  
       
     
  SEQUENCE      DATA       SSN                               STATION NAME                    
                     NUMBER       CODE                                                       
  
 (INC BY 10)                                                   Use *86* Record  Ŀ        
                                                                                            
        
45                     55  56                   65 66     69  70           75   76  77 78  
79     80
Ŀ Ŀ  Ŀ Ŀ Ŀ   Ŀ Ŀ   Ŀ  Ŀ  
Ŀ    Ŀ
.  .    .       
             M M M M M M M M   m m m    M M M M M M M   m m m   SPC/UTM     M M M M  
m m   ELEV. STATE   STA.   STA.
 Y-COORDINATE (NORTHING)    X-COORDINATE (EASTING)   ZONE         ELEVATION     CODE   CODE 
ORDER   TYPE
        (METERS)                   (METERS)                        (METERS)
                                                                                             
                                                                                             
                                                                                             
    

 


                                            2-106

          *82* REFERENCE OR AZIMUTH MARK RECORD

 1         6    7     10  11     14    15                                                    
    44 45    50  Ŀ  Ŀ  Ŀ   
Ŀ Ŀ
       
 
  SEQUENCE      DATA         SSN                               STATION NAME                  
         BLANK       NUMBER       CODE                                                       
  
 (INC BY 10)                                                                                 
                

                                        51     54   55                                       
   80
                                        Ŀ  
Ŀ
                                          

                                           SSN                           BLANK      
                                         CONTROL
                                         STATION

--------------------------------------------------------------------------------------------
------------------


          *83* BENCH MARK RECORD

NGS has discontinued the use of this record.  Effective immediately, record this vertical
control data in the Orthometric Height, Geoid Height, Ellipsoid Height Record (*86*) format
diagram.


      *84* GEOID HEIGHT RECORD (OPTIONAL)

NGS has discontinued the use of this record.  Effective immediately, record this data, if
required, in the Orthometric Height, Geoid Height, Ellipsoid Height Record (*86*) format
diagram.











                                            2-107
          *85* DEFLECTION RECORD (OPTIONAL)

 1         6   7     10 11     14  15         20   21                                        
      45
Ŀ Ŀ Ŀ  Ŀ  
Ŀ
      

  SEQUENCE      DATA       SSN        SOURCE                           COMMENT(S)
   NUMBER       CODE               ORGANIZATION
 (INC BY 10)                                   

46                               62  63         67  68    69     71  72         76    77   
78     80
Ŀ  Ŀ Ŀ  Ŀ   Ŀ Ŀ  Ŀ Ŀ    Ŀ  
Ŀ Ŀ
  .     .  .      
.
       COMMENT(S) CONTINUED           S S S   s s   DIR.   S   s s    S S S   s s     DIR.  
S   s s                                                      XI        OF   SIGMA OF XI     
ETA         OF   SIGMA OF ETA
                                       (SECONDS)    XI    (SECONDS)    (SECONDS)      ETA   
(SECONDS)
                                                   (N/S)                             (E/W)
--------------------------------------------------------------------------------------------
-------------------
          *86* ORTHOMETRIC / ELLIPSOID / GEOID HEIGHT RECORD (OPTIONAL)
 
 1         6   7     10 11     14   15 16   17             23     24    25     26      27    
 28 29
Ŀ Ŀ Ŀ   Ŀ   Ŀ Ŀ     Ŀ   Ŀ    Ŀ     Ŀ   
 Ŀ
        .                    
 
  SEQUENCE      DATA       SSN      BLANK    M M M M   m m m      OHT   OHT    OHT     OHT   
  OHT
   NUMBER       CODE                       ORTHOMETRIC HEIGHT     CODE ORDER  CLASS   NGSIDB 
 DATUM
 (INC BY 10)                                    (METERS)                            
INDICATOR

30         35   36             42   43    44 45   46             52     53    54    55    
56
Ŀ   Ŀ Ŀ   Ŀ   Ŀ   Ŀ Ŀ     Ŀ   Ŀ   Ŀ   
Ŀ
   .         .              

ORGANIZATION     M M M M   m m m    GHT   BLANK    M M M M   m m m      EHT   EHT   EHT   
EHT
               GEOID HEIGHT (GHT)   CODE          ELLIPSOID HEIGHT      CODE ORDER CLASS 
DATUM
                    (METERS)                          (METERS)

57                                             80
Ŀ 
 
                     COMMENT



                                            2-108

          *90* FIXED CONTROL RECORD

 1         6   7     10 11     14  15         20   21                                        
      45
Ŀ Ŀ Ŀ  Ŀ  
Ŀ
      

  SEQUENCE      DATA       SSN        SOURCE                           COMMENT(S)
   NUMBER       CODE               ORGANIZATION
 (INC BY 10)

46                                                       74     75     76       80
Ŀ     Ŀ    Ŀ
         
                 COMMENT(S) CONTINUED                           "G"     X X X X X
                                                                       NGS SOURCE
                                                                         NUMBER        

--------------------------------------------------------------------------------------------
-------------

  DATA SET TERMINATION RECORD
 
 1         6    7     10   11                                                                
      80
Ŀ  Ŀ  
Ŀ        
    
           
SEQUENCE       DATA                                          BLANK                  
   NUMBER        CODE
 (INC BY 10) 














                                            2-109



















                       INTENTIONALLY BLANK

































                              2-110

                            CHAPTER 3

          GEODETIC CONTROL DESCRIPTIVE (GEOD DESC) DATA


INTRODUCTION

The purpose of the description of a survey point is to convey to
the next user, in a concise and standard manner, information
sufficient to locate and positively identify the survey point,
and to record its suitability for various uses.  

This chapter gives detailed instructions for the entry and
interpretation of descriptive information for survey points of
all types.  A survey point (or station) may be a monumented
control point, a reference mark or azimuth mark, a landmark, or a
temporary, auxiliary, or eccentric point.  A description must be
submitted for every recoverable survey point which is observed in
a project, and for each of its peripheral points (if it has any). 
A collection of these descriptions constitutes the GEOD DESC data
set which must accompany any submitted project.  Descriptions can
also be submitted independently for miscellaneous recoveries of
monumented points already present in the NGS data base.  

NGS has begun the distribution of descriptions from the data base
for use in the field.  These descriptions can easily be modified
to make them current, and can then be resubmitted as complete
recovery descriptions.  This practice will greatly improve the
quality of descriptions available from the NGS data base, and
will save work in the long run.    

WRITING DESCRIPTIONS

A separate description is to be written for each monumented
survey point, be it a "main" station, a reference mark, or
azimuth mark.  "Underground" marks are an exception.  When a
control point has reference marks which are included in the NGS
data base, or are monumented well enough to carry geodetic
control themselves, each is to have its own separate description. 
The descriptive text for each mark in such a group would include
location references from the other marks in the group.  Such a
location reference to the described mark from a second mark would
identify the second mark by agency and designation, and would not
include a description of the second mark.  Peripheral marks,
points, or objects which are not included in the NGS data base
and are not suitable for holding control need not be separately
described.  In this case a short descriptive phrase may be
included in the location reference to the described mark from
that object, if necessary.  

When new text is submitted for a recovered mark, it must be
complete in itself as if it were for an original description. 
Text which merely amends a previous description will no longer be
allowed for recovered marks used in a project.  Now that
descriptions from the data base are being distributed in the same
format in which they are collected, the previous description can
simply be edited as necessary.  If no editing is necessary (that
is, if the description which was distributed from the data base
is still current, is complete, and is a single report), the mark
may be reported "recovered as described", and no new text need be
submitted. 

                               3-1A six-character Permanent Identifier (PID, formerly known as
ACRN) now serves as the primary means for matching recovery
description data against the data base for marks known to NGS. 
Where the PID is known, it must be entered in the description.  A
mark newly set or new to NGS will not have a PID until it is
loaded into the data base.  Any description without a PID must be
complete.  

STRUCTURE OF THE GEOD DESC DATA SET

Descriptive data are organized into 80-column fixed-format
records.  The record type is identified by a code in columns 7-10
of each description record.  Most descriptions must contain
records coded *10*, *13*, *20*, *26*, and *30* and may also
contain records coded *15*, *28*, and *29*.  Specific locations
within the records are reserved for the different data fields. 
Detailed explanations of the fields in each record type appear
later in this chapter.  All alphanumeric fields must be left-
justified.  All numeric data must be right-justified and zero
filled.  All alphabetic characters must be entered in upper case
(capitals) only.  

The first and last records of the data set (the Data Set
Identification Record and the Data Set Termination Record)
display the two-character alphanumeric job code preceded and
followed by an asterisk in the field normally occupied by the
first data code (columns 7-10).  Unless a job code is
specifically assigned to a project by NGS, this job code may be
sequentially assigned (*A1*,*A2*,...*ZZ*) by the submitting
agency.  Other fields in the identification record include the
name of the submitting agency and the date the data set was
created.  Detailed format definition of this record can be found
on the first page of the format diagram section.  In every record
of the data set, columns 1 through 6 are reserved for a record
sequence number.    

Each description in a file is identified by its station serial
number (SSN).  The SSN is a unique four-digit number assigned to
each mark in a project.  It is given in the *10* record which
begins the block of records for that station.  Sample data sets
appear at the end of the chapter, before the format diagrams.  

RECORD DEFINITIONS

Each record type and the acceptable entries for each data field
are explained in the following paragraphs.  Diagrams of the
formats are found at the end of the chapter.

TITLE AND COMMENT RECORDS

These records, if used, must appear immediately after the data
set identification record.  

CODE *00*, *01*, *02*, *03*, *04* (PROJECT AND TITLE INFORMATION
RECORDS)

These records are optional, and each can occur only once.  Usage
may vary.  They may correspond to the *10* and *11* records in
the horizontal observation data set documented in chapter 2, or
to the *10* through *14* records in the vertical observation data
set documented in volume II, chapter 6.  When data are exported
from the NGS data base, these records may indicate this, and give
information about what marks are included.  Do not split words
between these records.  
                               3-2CODE *05* (COMMENT RECORD) (optional)

Comment records may contain additional text describing the data
set or the project.  Up to 11 are allowed.  Again, do not split
words between records.  

DESCRIPTION RECORDS

CODE *10* (STATION LOCATION RECORD)

This first record primarily contains information pertinent to
station location.  The individual entries made in this record are
as follows:  

   Station Serial Number (SSN) [CC 11-14] -  This four-digit
   numeric field is the project-specific link between
   descriptive and observational data. The field must be unique
   for each station residing in the descriptive and
   observational data sets.  Recovery descriptions for stations
   not included in the observational data set may reside in the
   description data set, but in no case should their station
   serial numbers correspond to station serial numbers in the
   companion observation data set.

   DR Code [CC 15] -  This one-character code indicates whether
this  description is an original description or a recovery
      description. The allowable entries are "D" and "R".  

      ENTRY  DEFINITION

      D      An original description of a newly set mark.

      R      Everything else (includes recovered, not recovered,
             destroyed, and the first report to NGS of a pre-
             existing mark not in the NGS data base).  

   Recovery Type Code (optional) [CC 16] -  This one-character
   code provides additional information about the type of
   recovery description being included in the description data
   set.  It is used only when the DR Code = "R".  The allowable
   entries are:

      ENTRY  DEFINITION

      F      A full recovery description of a survey point which
             you think is not included in the NGS Data Base.

      M      A recovery description which does not contain a
             complete textual description of the mark, but may
             contain updates or modifications to the most
             current description.  This is used when a mark is
             destroyed or not recovered, or when the text of the
             previous description of this mark in the NGS data
             base requires no update (i.e., the text is in
             accord with current practice, and the situation at
             the mark has not changed).  

      T      A complete re-description of a mark which is
             included in the NGS data base.



                               3-3
   Note:  The practice of submitting recovery notes for stations
          used in a project which give only text modifications to
          a previous description is no longer permitted. 


   Approximate Position [CC 17-31] -  The approximate geographic
   position in degrees, minutes, and the nearest whole seconds
   of latitude and longitude must be entered.  The latitude [CC
   17-23] must begin with a hemisphere code (N=NORTH, S=SOUTH)
   and the longitude [CC 24-31] must begin with the direction-
   letter "W" . Leading zeros must be entered where appropriate. 
   If no other source is available, the point should be
   carefully plotted on the largest scale topographic map
   available and the respective latitude and longitude extracted
   therefrom.  Latitude and longitude are required under all
   circumstances.
   
   Approximate Height [CC 32-36] -  An estimated height of the
   geodetic control point is entered here.  If no other source
   is available, the height may be estimated by examining
   contour lines on the largest scale topographic map available
   on which the point is plotted.  The entry should be made to
   the nearest whole unit of measurement used.  The unit of
   measurement (M=METERS, F=FEET) is also recorded [CC 37].

   Quad Identifier (Quadrangle or QID) (optional) [CC 39-45] - 
   This was at one time part of the primary identification
   system adopted by the National Geodetic Survey Data Base for
   control points.  The new Datum has rendered it obsolete.  It
   will be phased out, but is still provided as a convenience in
   the interim.  It is based on 1x 1 "quads" defined by
   integer-degree latitude and longitude gridlines (parallels
   and meridians) and on successive quadrangle subdivision of
   the basic 1x 1 quads into 30'x 30' quads, 15'x 15' quads,
   and 7'x 7' quads accomplished by successive halving of the
   latitude and longitude gridline intervals.  For description
   purposes, only the 30' quad identifier will be recorded. 
   This quad identifier is a seven-character symbol coded as
   HLLWWWA, where:

      H=Hemisphere (N for Northern, S for Southern)
      LL=Latitude of SE corner of the 1x 1 quad (00-89N,
      01-90S)
      WWW=Longitude of SE corner of the 1x 1 quad (000-359W)
      A=30' subdivision indicator (1-NE,2-SE,3-SW,4-NW subquad)

   Note that for some marks the Quad value based on the NAD 83
position will   not be the same as the traditional Quad value
                based on the NAD 27 position.  It is these
                latter values which were once published.  


   Figure 3-1 depicts this scheme in graphic format.










                               3-4


 
  
 
                                                   31 DEGREES
    Ŀ
                                      |     |  X>POINT TO BE
                                      |.....1.....   IDENTIFIED
                                      |     |     
               4                1     
                                      |           
                                      |           
                                      |           
                                      |           
    Ĵ 30 DEG 30 MIN
                                                  
                                                  
                                                  
                                                  
               3                      2           
                                                  
                                                  
                                                  
                                                  
     30
   110 DEGREES                                    109
 
                                                QID =N 3 0 1 0 9 11 1
                                                     v
                                                     30 Minute Quad
               30 Minute indicator                     Identifier
                  Numbers describe 30 minute
                  area in clockwise direction.
 
               Number range (1 thru 4)
 
               15 Minute indicator
                  Division shown by dashed lines
                  Numbering same as 30 minute
                  sequence.
 
               7.5 Minute indicator
                  Division shown by dotted line
                  Numbering same as 30 minute
                  sequence.
 
 
 







 
                  FIGURE 3-1 - QUAD IDENTIFIER.








                               3-5   State or Country Code [CC 47-48] -  This is a two-letter code
   which indicates the political unit and/or geographic area in
   which the control point is located.  For points in the United
   States or Canada, enter the appropriate code for the
   respective state, commonwealth, province, or territory.  For
   points outside the United States or Canada, enter the
   appropriate code for the respective country, island group, or
   geographic area.  A complete list of the two-letter codes is
   given in ANNEX A.

   County [CC 49-68] -  For points in the United States or
   Puerto Rico, enter the name of the county or equivalent in
   which the control point is located.  The name of an
   independent city must be preceded by the prefix "C OF" (i.e.,
   C OF RICHMOND for RICHMOND, VA).  For points in other
   countries, leave the field blank.

   Special Application Codes [CC 69-72] -  Up to four alpha
   characters, left justified, are allowed in this field.  These
   characters represent certain specialized information about
   the control point.  All entries must be selected from the
   following list:

      ENTRY  DEFINITION

      F      Fault monitoring site
      P      Site determined suitable for receiving satellite
             signals in connection with geodetic surveys
      O      Other (see descriptive text)
      T      Tidal station
      N      Site not suitable for receiving satellite signals


   Permanent Identifier (PID) (optional) [CC 73-78] -  The PID
   is now the primary identification system used by NGS for
   control points.  For a mark that had an ACRN, the ACRN is now
   the PID.  The PID is a unique six-character identifier
   assigned to every monumented, recoverable survey point
   residing in the National Geodetic Survey Data Base.  For an
   existing point, the PID assigned by NGS must be entered if it
   is available.  If it cannot be determined, the field should
   be left blank.  For a new point, this field must be left
   blank, and a PID will be assigned when the mark is loaded
   into the NGS data base.  


CODE *13* (STATION IDENTIFICATION RECORD)

The second record required for geodetic control stations contains
the agency name for the point.  The entries made are as follows:

   Designation [CC 11-50] -  Up to 40 characters of alphanumeric
   data may be entered into this field.  In the case of existing
   marks already included in the NGS data base, the designation
   should precisely reflect the published designation of the
   station.  This is the official designation.  As control
   points are added to the geodetic network, station
   designations should be unique within a clearly defined
   geographic locale (e.g., state, province).  Where station
   monuments have been stamped, the designation is an edited
   version of what is stamped on the marker.  This practice
   should be followed as nearly as possible.  ANNEX D supplies
   detailed instructions  

                               3-6   concerning naming conventions for geodetic control points. 
   Assistance concerning determination of unique designations
   can be obtained by contacting NGS.

   Underground Marker Type and Magnetic Property Code (optional)
   [CC 52-53] and [CC 55] -  These codes are similar to the
   codes used for surface marker type and magnetic code on the
   setting record.  If an underground marker exists and these
   codes can be determined for it, they are entered here. 
   Entries must be left-justified.  A complete list of the codes
   is contained in ANNEX I.

   Setting Code (Underground Marker) (optional) [CC 57-58] - 
   The setting code is from a comprehensive set of two-digit
   numerical codes covering a wide variety of possible settings
   for a survey point marker.  A complete list of the setting
   codes is found in ANNEX I.

   Transportation Code [CC 60] -  This is a one-letter code that
   indicates the mode of transportation to reach the station. 
   If backpacking is required to reach the station, the
   transportation code reflects the mode of travel used to reach
   the point where backpacking begins. A complete list of the
   specific transportation codes is given below.  The possible
   entries are as follows:

      CODE            TRANSPORTATION MODE

        A           Light Airplane
      B             Boat
      C             Car (or Station Wagon)
      F             Float Airplane
      H             Helicopter
      O             Other (See Descriptive Text)
      P             Light Truck (Pickup,Carry-All, etc.)
      T             Truck (larger than 3/4 ton)
      W             Tracked Vehicle (Weasel,Snowcat,etc.)
      X             Four-Wheel Drive Vehicle


   Backpack-Time (optional) [CC 63-66] -  Enter the time
   required to carry equipment on foot from the last point of
   transportation to the station, expressed in hours and minutes
   (HHMM).  If the immediate vicinity of the station can be
   reached using the mode of transportation indicated by the
   preceding transportation code, enter zero in both the hours
   and minutes fields (0000).


CODE *15* (ALIAS RECORD) (optional) [CC 11-50] -  Up to 40
characters of text which represent an alternate form of the name
used to identify the control point.  These alias entries arise
due to non-standard naming conventions used by various agencies
and individuals.  NGS strongly discourages the use of aliases.






                               3-7CODE *20* (MONUMENTED/RECOVERED RECORD) -  Entries in this record
primarily provide historical information concerning creation of
and subsequent return visits to the control point.  The first
four fields are normally used only when the DR Code = "D" and the
remaining five fields are used only when the
DR Code = "R".  Acceptable entries for each field are defined as
follows:
   
   Monumenting Agency Group Code [CC 11] -  The code for the
   monumenting agency group is a one-character alpha entry used
   to subdivide specific monumenting organizations into distinct
   groups.  These codes follow:

      CODE   GROUP

      A      National Agencies
      B      Inter-State or Inter-Province Agencies
      C      State, Province, Commonwealth, and Territorial
             Agencies
      D      County Agencies
      E      Municipal Agencies (Cities)
      F      Inter-City and Inter-County Agencies
      G      Railroads
      H      Utility and Natural Resource Companies
      I      Surveying, Engineering, and Construction Industry
      J      Educational Institutions
      K      Professional and Amateur Associations
      L      Miscellaneous Commercial or Private Firms
      M      Non-Specific Designators


   Monumenting Agency Symbol [CC 13-18] -  This is the NGS-
   defined symbol
   of up to six (6) characters for the organization which set
   the monument (disk).  It is required when the DR Code is "D",
   and is optional if the
   DR Code is "R".  The symbols are given in ANNEX C.  If the
   organization is not listed in ANNEX C, contact NGS to have a
   symbol assigned to that organization.

   Year Monumented [CC 33-36] -  Enter the year the marker was
   monumented.  It is required when the DR Code is "D", and is
   optional if the DR Code
   is "R".   

   Chief of Party [CC 37-39] -  Enter up to three initials for
   the person who was in charge of the survey party which
   monumented the control point.  If this information cannot be
   determined, as in the case of recovery stations, leave the
   field blank.  This field is always optional.

   Recovering Agency Group Code [CC 42] -  In a manner similar
   to that described for the Monumenting Agency Code, enter the
   appropriate group code from the list above for the recovering
   organization. 

   Recovering Agency Symbol [CC 44-49] -  This is the NGS-
   defined symbol of up to six (6) characters for the
   organization which recovered the mark.  It is required when
   the DR Code is "R", and is not allowed if the DR Code
   is "D".

   Date Recovered [CC 64-71] -  The exact date the control point
   was recovered is to be recorded in this eight-character
   field.  The year,


                               3-8
   month, and day of the month are to be recorded in that
   sequence (e.g., 19850815 would indicate August 15, 1985).  It
   is required when the DR Code is "R", and is not allowed if
   the DR Code is "D".

   Chief of Party [CC 72-74] -  If DR Code = "R", enter up to
   three initials for the person who was in charge of the survey
   party which recovered the control point.  This field is
   optional when the DR Code is "R", and is not allowed if the
   DR Code is "D".
   
   Recovery Condition Code [CC 77] -  If DR Code = "R", enter
   the appropriate one-letter code to indicate the condition of
   the control point.  It is required when the DR Code is "R",
   and is not allowed if the DR Code is "D".  The allowed values
   are as follows:
              
      CODE   CURRENT CONDITION OF SURVEY POINT

      G      Good
      N      Not Recovered, Not Found
      P      Poor, Disturbed, Mutilated, Requires Maintenance
      X      Destroyed (See Note Below)
   
   Note: The control point should be reported as destroyed only
   when the actual marker is found separated from its setting
   (e.g., disk recovered from highway department personnel).  If
   the marker was not found, notes
   concerning evidence of possible destruction should be entered
   as text
   records, but the recovery condition entry should be coded as
   "N".


CODE *26* (SETTING RECORD) -  This record contains information
about the setting of the surface marker, its stability, and in
some cases, what identifying features are inscribed or cast (as
opposed to hand-stamped) on the marker.  The definition of each
field is as follows:

   Setting Code [CC 11-12] -  This two-digit code is used to
   indicate the setting characteristics of the monument or mark. 
   These characteristics include the type of setting (shallow or
   deep), the type of design and material used for the monument, 
   and/or the natural or man-made object which serves as the
   setting for the control point.  A complete list of the
   possible entries is found in ANNEX I.

   Specific Setting Phrase [CC 14-45] - For setting codes 30
   through 41, enter a more specific phrase describing the
   setting, but corresponding to the respective setting code
   chosen from the list in Annex I.  A maximum of 32 characters,
   including imbedded blanks, may be entered.  For the other
   setting codes, leave this field blank.  If the setting code
   or specific setting phrase does not adequately represent the
   setting of the mark, additional explanation should be given
   in the text.

   Surface Marker Type [CC 46-47] -  This field identifies the
   object used to monument the geodetic control point.  Landmark
   stations are represented by two (2) digit codes and all other
   markers represented by one or two
   character alpha codes.  Entries must be left-justified.  The
   most common types of surface marks are listed on the next
   page:



                               3-9
      CODE      DESCRIPTION

      A         Aluminum marker (other than a disk)
      B         Bolt
      C         Cap-and-Bolt Pair
      DB        Bench Mark Disk
      DD        Survey Disk
      DE        Traverse Station Disk
      DH        Horizontal Control Disk
      DJ        Tidal Station Disk
      DO        Disk of Unspecified Type (See Text)
      DQ        Calibration Base Line Disk
      DR            Reference Mark Disk
      DS        Triangulation Station Disk
      DU        Boundary Marker Disk
      DV        Vertical Control Disk
      DZ        Azimuth Mark Disk
      I         Metal Rod
      N         Nail

   A complete list of these codes is contained in ANNEX I.

   Magnetic Code (Surface Marker) [CC 49] -  This one-character
   code indicates the magnetic property of the mark or monument. 
   ANNEX I details acceptable entries for the magnetic property
   code.

   Vertical Stability Override Code (optional) [CC 51] -  This
   one-character entry allows the default vertical stability
   codes to be overridden when appropriate.  The codes are from
   the following list:

      CODE   DEFINITION

      A      Monuments of the most reliable nature, expected to
             hold their elevations very well.

      B      Monuments which generally hold their elevations
             fairly well.

      C      Monuments which may be affected by surface ground
             movements.

      D      Monuments of questionable or unknown vertical
             stability.  

   Marker Inscription [CC 54-59] -  This field is the symbol
   from ANNEX C for the agency or organization whose identity is
   inscribed or precast on the disk/monument.  This entry is not
   the same as the stamping which usually reflects the station
   designation.  If the appropriate organization is not listed
   in ANNEX C, contact NGS to have a symbol assigned to that
   organization.   If it is not possible to contact NGS, a
   longer entry (up to 26 characters) may be made.  If there is
   no agency identification inscribed or precast on the marker
   (such as a chiseled square, nail, or unidentified disk),
   enter "UNK" .

   
CODE *28* (STAMPING RECORD) (optional) -  The stamping field [CC
11-60] should contain the exact stamping as it appears on the
geodetic control marker.  The entry must not exceed 50
characters, including embedded blanks.  If there is no stamping,
make no entry here;  however, if the marker is a type that is
normally stamped, enter a short note about its being unstamped in
the accompanying descriptive text. 
                              3-10
CODE *29* (ROD/PIPE RECORD) (optional) -  Inclusion of this
record as a separate entity allows users to access specific
information about this class of survey point.  This record would
be used in lieu of the phrase STAINLESS STEEL (or other material
as per Setting code) ROD (OR PIPE) SET TO THE DEPTH OF ____
METERS (or FEET, depending on the UNITS CODE), IN A SLEEVE
EXTENDING TO THE DEPTH OF ____ METERS (or FEET), ENCASED IN A
PIPE FLUSH (F) WITH THE GROUND [or PROJECTING (P)/RECESSED (R) XX
in centimeters (or XX in inches)] or, for an unsleeved rod mark,
in lieu of the same phrase without reference to sleeve depth (if
the sleeve depth field is left blank).  For first-time recovery
descriptions of pre-existing rod- or pipe-type markers, all
pertinent data must be entered.  Otherwise, enter any known
information in the text instead of using a *29* Rod/Pipe Record. 
For example, if the actual rod depth is unknown, enter the
projection/recession reference and a note (e.g., ROD DEPTH IS
UNKNOWN), in the text.  Left-justify any values recorded on this
record.  NGS prefers metric values.

   UNITS CODE [CC 11]     DEFINITION

      E                English - The units are feet and inches.

      M                Metric  - The units are meters and
                       centimeters.


CODE *30* (TEXT RECORDS) -  Descriptive text provides information
about the mark which is not captured in the coded fields.  It is
entered in multiple records with up to 70 characters per record. 
Words must not be split between records.   In addition to the
expected alphanumeric character set (A-Z and 0-9), the following
special characters are allowed:

   (*)  asterisk                 (+)  plus sign
   ( )  blank or space           (-)  minus sign
   (,)  comma                    (=)  equal sign
   ($)  dollar sign              (()  left parenthesis
   (/)  slash                    ())  right parenthesis
   (.)  period or decimal

Every effort must be made to provide enough information for easy
recovery of the point.  A well written description should
contain: 

(1)   one or more references to some well known, readily
      available, location in terms of distances and directions. 
      Intersections of prominent highways, landmarks, and public
      buildings in nearby towns are examples of such locations. 
      In some cases, this location will require some
      description;

(2)   detailed directions concerning how one would proceed to
      the mark site from one or more of these prominent
      locations;

(3)   distance and direction to, inscription, and designation of
      any monumented reference marks which are in the NGS data
      base.  Specific descriptions of these reference marks
      themselves are not to be included:  each reference mark
      must have a separate complete description of its own;  

(4)   distance and direction from one or more reference objects
      in the immediate locale should be noted.  Examples of
      these reference objects are the centerlines of roads, fire
      plugs, telephone poles, chiseled marks in pavement, and
      survey marks which are not included in the NGS data base. 
      

                              3-11
   This item is more important when no monumented reference
   marks are associated with the geodetic control point;

(5)   distance and direction to any witness post that was set or
      if any witness post was set;

(6)   if applicable, a vertical reference to some nearby object
      (or the ground) stating the relationship to the object
      should be recorded.  Distance above, below, or about flush
      with the object should be noted; and

(7)   any information about the specific setting or exact
      location of the mark if the coded values are not
      sufficient to describe it completely.

When distance estimates or measurements are given in metric
units, English equivalencies must follow in parentheses. 
Property ownership and contact point telephone numbers are
desirable when private property must be crossed or occupied.      
                                 

Varying styles of descriptive text are used by some local and
regional agencies.  This will not present a problem as long as
the content is as specified.  Examples of descriptive text are
included in the sample data sets which follow.


000010*AA*GEODDESCNGS   NATIONAL GEODETIC SURVEY                      
 19910413
000020*00*GPS-301                                                     
         
000030*01*COLORADO HIGH PRECISION GEODETIC SURVEY, 1991               
         
000040*05*THESE DESCRIPTIONS WERE TAKEN FROM THE ABOVE PROJECT AND
MODIFIED TO  
000050*05*SERVE AS EXAMPLES.                                          
         


This description represents a fairly typical situation.

000060*10*0049RTN370756W103530801778M         COLAS ANIMAS          P 
 HJ0138  
000070*13*D 85                                             P  0000    
         
000080*20* /                             A/NGS                
19910415GRH  G   
000090*26*07/                                DB N C  CGS              
         
000100*28*D 85 1935                                                   
         
000110*30*STATION IS LOCATED ABOUT 55 KM (34.2 MI) EAST OF TRINIDAD,
14 KM      
000120*30*(8.7 MI) NORTH OF BRANSON, 4 KM (2.5 MI) SOUTH OF WALTS
CORNER        
000130*30*(JUNCTION OF US HIGHWAY 160 AND STATE HIGHWAY 389), ALONG
HIGHWAY     
000140*30*389, AT MILE 10.1, IN A PASTURE, IN THE NORTHEAST CORNER OF
SECTION   
000150*30*34, T 33 S, R 58 W.  OWNERSHIP--WALDROUP RANCH, INC,
BRANSON, CO      
000160*30*81027.
000170*30*NOTE--IT IS NECESSARY TO PARK IN ROAD SO APPROPRIATE
WARNING EQUIPMENT
000180*30*IS NEEDED.                                                  
         
000190*30*TO REACH FROM THE VEE FORMED BY HIGHWAY 389 SPLITTING TO
JOIN HIGHWAY 
000200*30*160, ABOUT 0.1 KM (0.1 MI) SOUTH OF HIGHWAY 160, GO SOUTH
ON HIGHWAY  
000210*30*389 FOR 3.39 KM (2.11 MI) TO A TRACK ROAD LEFT LEADING TO A
WINDMILL. 
000220*30*CONTINUE AHEAD FOR 0.64 KM (0.40 MI) TO THE STATION ON THE
RIGHT.     
000230*30*STATION MARK IS SET IN THE TOP OF A 20-CM SQUARE CONCRETE
POST        
000240*30*PROJECTING 15 CM.  IT IS 9.9 M (32.5 FT) WEST OF, AND 1 M
(3.3 FT)    
000250*30*LOWER THAN THE HIGHWAY CENTER, 1.3 M (4.3 FT) WEST OF A
FIBERGLASS    
000260*30*WITNESS POST IN THE RIGHT-OF-WAY FENCE, AND 161 M (528.2
FT) NORTH OF 
000270*30*MILEPOST 10 (MEASURED ALONG THE ROAD).
                                
                                3-12
More text is required under other circumstances.

000280*10*0216RFN350230W106365201619M         NMBERNALILLO            
         
000290*13*NM BASE 1                                        P  0000    
         
000300*20* /                             A/NGS                
19910531EAR  G   
000310*26*00/                                Z  N B                   
         
000320*30*THE STATION IS LOCATED ABOUT 4.8 KM (3.0 MI) SOUTHEAST OF
ALBUQUERQUE,
000330*30*AT THE ALBUQUERQUE INTERNATIONAL AIRPORT, ABOUT 1.2 KM (0.7
MI)       
000340*30*WEST-NORTHWEST OF THE AIRPORT CONTROL TOWER, ON THE
NORTHEAST SIDE OF 
000350*30*RUNWAY 12-30, NEAR A TAN BRICK BUILDING. OWNERSHIP--CITY OF 
         
000360*30*ALBUQUERQUE, ROBERT E. GILL, AVIATION SUPERVISOR, P.O. BOX
9022,      
000370*30*ALBUQUERQUE, NM 87119.  PHONE IS 505-842-4366.              
         
000380*30*NOTE--ESCORT TO STATION BY AIRPORT POLICE IS MANDATORY. 
AIRPORT      
000390*30*SECURITY MAY BE REACHED BY PHONE AT WEST SECURITY ENTRANCE
GATE BY    
000400*30*DIALING 4380.                                               
         
000410*30*TO REACH THE STATION FROM THE WEST SECURITY ENTRANCE GATE
AT THE AIR  
000420*30*FREIGHT LOADING DOCKS AT THE ALBUQUERQUE INTERNATIONAL
AIRPORT, PASS  
000430*30*THROUGH GATE AND GO SOUTH FOR 6 M (19.7 FT) ON ASPHALT
SURFACE TO A   
000440*30*FENCE.  TURN LEFT AND GO EAST FOR 0.1 KM (0.1 MI) ON
ASPHALT SURFACE  
000450*30*TO THE EAST END OF THE FENCE.  TURN RIGHT AND GO
SOUTHWESTERLY FOR    
000460*30*0.2 KM (0.1 MI) ON ASPHALT SURFACE TO SERVICE ROAD C.  TURN
LEFT AND  
000470*30*GO SOUTH FOR 0.9 KM (0.6 MI) ON SERVICE ROAD C TO A PAVED
ROAD LEFT   
000480*30*AND SIGN (T-16).  TURN LEFT AND GO EAST FOR 0.5 KM (0.3 MI)
ON THE    
000490*30*PAVED ROAD, PASSING CUTTER AVIATION, TO A DIRT ROAD LEFT
AND SIGN     
000500*30*(T-13). TURN LEFT AND GO NORTH FOR 0.2 KM (0.1 MI) ON THE
DIRT ROAD,  
000510*30*CROSSING TWO RAMPS TO A TAN BRICK BUILDING (RUNWAY LIGHTING
VAULT)    
000520*30*WITH TWO GREEN ELECTRICAL BOXES AND THE STATION ON THE
SOUTH SIDE OF  
000530*30*BUILDING.                                                   
         
000540*30*THE STATION IS THE TOP CENTER OF A ROUND METAL PLATE THAT
IS          
000550*30*UNSTAMPED, AFFIXED TO THE TOP OF A 15.24 M (50.00 FT) LONG
STEEL      
000560*30*H-BEAM DRIVEN TO A DEPTH OF 14.0 M (45.9 FT) , PROJECTING
1.2 M       
000570*30*(3.9 FT) ABOVE GROUND, ENCASED IN A 2.1 M (6.9 FT) LONG     
         
000580*30*INSULATION-FILLED PVC PIPE 45 CM IN DIAMETER SET AT A DEPTH
OF 0.9 M  
000590*30*(3.0 FT) PROJECTING 1.2 M (3.9 FT) ABOVE GROUND, SURROUNDED
BY A      
000600*30*SQUARE CONCRETE SLAB 1.2 M (3.9 FT) ON SIDE FLUSH WITH
GROUND.        
000610*30*LOCATED 45.4 M (148.9 FT) WEST FROM THE SIXTH BLUE TAXIWAY
LIGHT      
000620*30*ALONG TAXIWAY 14 (SOUTH OF TAXIWAY 2), 32.3 M (106.0 FT)    
         
000630*30*EAST-NORTHEAST FROM THE APPROXIMATE CENTER OF THE DIRT
ROAD, 21.8 M   
000640*30*(71.5 FT) SOUTH FROM THE SOUTHEAST CORNER OF THE RUNWAY
LIGHTING      
000650*30*VAULT AND 21.5 M (70.5 FT) SOUTHEAST FROM THE SOUTHWEST
CORNER OF THE 
000660*30*RUNWAY LIGHTING VAULT.                                      
         
000670*30*NOTE--THERE IS AN INVERTED THREADED BOLT AFFIXED TO THE TOP
CENTER OF 
000680*30*ROUND METAL PLATE.  FOR GPS OCCUPATION, ANTENNA TRIBRACH
WAS SCREWED  
000690*30*ON THE BOLT AND ANTENNA MEASUREMENT WAS REFERENCED TO TOP
OF ROUND     
000700*30*METAL PLATE.                                                
         


The following several descriptions illustrate how a cluster of
related marks should be described.  Note that NCMN is not an agency,
but a usage, like TIDAL.

000730*10*6614RTN401058W104433501520M         COWELD                P 
 LL1438  
000740*13*PLATTEVILLE NCMN                                 P  0000    
         
000750*20* /                             A/NGS                
19910515GRH  G   
000760*26*07/                                DH N C  NGS              
         
000770*28*PLATTEVILLE NCMN 1981                                       
         

                                3-13
000780*30*STATION IS LOCATED ABOUT 9.5 KM (5.9 MI) SOUTHEAST OF
PLATTEVILLE, AT 
000790*30*THE PLATTEVILLE RADAR SITE, ABOUT 75 M (246.1 FT) NORTHWEST
OF THE    
000800*30*MAIN BUILDING, IN THE MIDDLE OF THREE 1.7 M (5.6 FT) X 2.7
M          
000810*30*(8.9 FT) CONCRETE PADS, IN THE CENTER OF SECTION 36, T 3 N,
R 66 W.   
000820*30*OWNERSHIP--US DEPARTMENT OF COMMERCE, NATIONAL
COMMUNICATIONS AND     
000830*30*INFORMATION ADMINISTRATION, NOAA, WPL, REWP 4, 325
BROADWAY, BOULDER, 
000840*30*CO 80303.  PHONE IS 303-497-6385 FOR COMBINATION TO GATE
LOCK.        
000850*30*TO REACH FROM THE JUNCTION OF US HIGHWAY 85 AND STATE
HIGHWAY 66 AT   
000860*30*THE SOUTH END OF PLATTEVILLE, GO SOUTH ON HIGHWAY 85 FOR
2.05 KM      
000870*30*(1.27 MI) TO A CROSSROAD.  TURN LEFT, EAST, ON GRAVEL ROAD
(ROAD 28)  
000880*30*FOR 7.20 KM (4.47 MI) TO ROAD END AT A THREE-WAY FORK AND A
LOCKED    
000890*30*GATE ON MIDDLE ROAD.  PASS THROUGH GATE AND GO SOUTHEAST ON
GRADED    
000900*30*ROAD FOR 1.21 KM (0.75 MI) TO A GRAVEL DRIVEWAY LEFT ABOUT
200 FT     
000910*30*(61.0 M) BEFORE REACHING MAIN BUILDING.  TURN LEFT,
NORTHEAST, FOR 25 
000920*30*M (82.0 FT) TO THE STATION ON THE LEFT.                     
         
000930*30*STATION MARK IS SET IN THE TOP OF A 30-CM ROUND CONCRETE
POST IN THE  
000940*30*MIDDLE OF A 1.2 M (3.9 FT) SQUARE CONCRETE PAD FLUSH WITH
THE GROUND. 
000950*30*IT IS 26.7 M (87.6 FT) NORTHEAST OF THE ROAD CENTER, 9.6 M
(31.5 FT)  
000960*30*SOUTHWEST OF A FIBERGLASS WITNESS POST, 12.2 M (40.0 FT)    
         
000970*30*WEST-SOUTHWEST OF A FENCE CORNER, 34.7 M (113.8 FT)
WEST-NORTHWEST OF 
000980*30*A UTILITY POLE WITH LIGHT, APPROXIMATELY 90 M (295.3 FT)
SOUTH OF NGS 
000990*30*MARK PLATTEVILLE NCMN RM 1, 86.5 M (283.8 FT)
WEST-NORTHWEST OF NGS   
001000*30*MARK PLATTEVILLE NCMN RM 2, 62 M (203.4 FT) NORTHEAST OF
NGS MARK     
001010*30*PLATTEVILLE NCMN RM 3, AND 49.4 M (162.1 FT) NORTHWEST OF
PLATTEVILLE 
001020*30*NCMN RM 5.                                                  
         


001030*10*8887RTN401058W104433401519M         COWELD                P 
         
001040*13*PLATTEVILLE NCMN RM 1                    DR N 07 X  0005    
         
001050*20*A/NGS                 1981     A/NGS                
19911119EAR  G   
001060*26*07/                                DR N C  NGS              
         
001070*28*PLATTEVILLE NCMN NO 1 1981                                  
         
001080*30*THE STATION IS LOCATED ABOUT 9.5 KM (5.9 MI) SOUTHEAST OF
PLATTEVILLE,
001090*30*AT THE PLATTEVILLE RADAR SITE, IN THE CENTER OF SECTION 36,
T 3 N, R  
001100*30*66 W.  OWNERSHIP--US DEPARTMENT OF COMMERCE, NATIONAL
COMMUNICATIONS  
001110*30*AND INFORMATION ADMINISTRATION, NOAA, WPL, REWP 4, 325
BROADWAY,      
001120*30*BOULDER, CO 80303.  PHONE IS 303-497-6385 FOR COMBINATION
TO GATE     
001130*30*LOCK.                                                       
         
001140*30*TO REACH FROM THE JUNCTION OF US HIGHWAY 85 AND STATE
HIGHWAY 66 AT   
001150*30*THE SOUTH END OF PLATTEVILLE, GO SOUTH ON HIGHWAY 85 FOR
2.05 KM      
001160*30*(1.27 MI) TO A CROSSROAD.  TURN LEFT, EAST, ON GRAVEL ROAD
(ROAD 28)  
001170*30*FOR 7.20 KM (4.47 MI) TO THE ROAD END AT A THREE-WAY FORK
AND A       
001180*30*LOCKED GATE ON THE MIDDLE ROAD.  PASS THROUGH GATE AND GO
SOUTHEAST   
001190*30*ON GRADED ROAD FOR 0.50 MI (0.80 KM) TO A GRAVELED
CROSSROAD.  TURN   
001200*30*LEFT AND GO EAST FOR 90 M (295.3 FT) TO THE STATION ON THE
RIGHT      
001210*30*INSIDE A METAL FENCE.                                       
         
001220*30*THE STATION IS AN REFERENCE MARK DISC SET IN THE TOP OF A
30-CM ROUND 
001230*30*CONCRETE POST PROJECTING 10 CM, WITH A WOODEN STAND. 
LOCATED 91.5 M  
001240*30*(300.2 FT) NORTHEAST OF THE ROAD CENTER, 54.9 M (180.1 FT)
NORTHEAST  
001250*30*OF AN ELECTRIC FENCE, 8.5 M (27.9 FT) SOUTH-SOUTHEAST OF A
METAL      
001260*30*FENCE, AND 90 M (295.3 FT) NORTH OF NGS MARK PLATTEVILLE
NCMN.        





                                3-14
001270*10*8888RTN401058W10443340 1519M         COWELD                 
          
001280*13*PLATTEVILLE NCMN RM 2                            C  0000    
         
001290*20*A/NGS                 1981     A/NGS                
19911119EAR  G   
001300*26*07/                                DR N C  NGS              
         
001310*28*PLATTEVILLE NCMN NO 2 1981                                  
         
001320*30*THE STATION IS LOCATED ABOUT 9.5 KM (5.9 MI) SOUTHEAST OF
PLATTEVILLE,
001330*30*AT THE PLATTEVILLE RADAR SITE, IN THE CENTER OF SECTION 36,
T 3 N, R  
001340*30*66 W.  OWNERSHIP--US DEPARTMENT OF COMMERCE, NATIONAL
COMMUNICATIONS  
001350*30*AND INFORMATION ADMINISTRATION, NOAA, WPL, REWP 4, 325
BROADWAY,      
001360*30*BOULDER, CO.80303.  CALL 303-497-6385 FOR COMBINATION TO
GATE LOCK.   
001370*30*TO REACH FROM THE JUNCTION OF US HIGHWAY 85 AND STATE
HIGHWAY 66 AT   
001380*30*THE SOUTH END OF PLATTEVILLE, GO SOUTH ON HIGHWAY 85 FOR
2.05 KM      
001390*30*(1.27 MI) TO A CROSSROAD.  TURN LEFT, EAST, ON GRAVEL ROAD
(ROAD 28)  
001400*30*FOR 7.20 KM (4.47 MI) TO THE ROAD END AT A THREE-WAY FORK
AND A       
001410*30*LOCKED GATE ON THE MIDDLE ROAD.  PASS THROUGH GATE AND GO
SOUTHEAST   
001420*30*ON GRADED ROAD FOR 1.01 KM (0.63 MI) TO A GRAVEL ROAD LEFT
JUST       
001430*30*BEFORE REACHING MAIN BUILDING.  TURN LEFT FOR 36.6 M (120.1
FT) TO A  
001440*30*LIGHT POLE AND TWO NASA TRAILERS.  THE STATION IS ABOUT 55
M          
001450*30*(180.4 FT) EAST IN A FENCED FIELD.                          
         
001460*30*THE STATION IS A REFERENCE MARK DISK SET IN THE TOP OF A 30
CM ROUND  
001470*30*CONCRETE POST PROJECTING 15 CM. LOCATED 55 M (180.4 FT)
EAST OF A     
001480*30*LIGHT POLE, 22.6 M (74.1 FT) EAST-NORTHEAST OF AN 8-INCH
SQUARE WIRE  
001490*30*GATE POST UNDER POWER LINES, 17.4 M (57.1 FT)
EAST-SOUTHEAST OF AN    
001500*30*8-INCH ROUND CORNER FENCE POST, 1.2 M (3.9 FT) SOUTHWEST OF
A LONE    
001510*30*METAL FENCE POST, 86 M (282.2 FT) EAST-SOUTHEAST OF NGS
MARK          
001520*30*PLATTEVILLE NCMN, AND 46 M (150.9 FT) EAST-NORTHEAST OF NGS
MARK       
001530*30*PLATTEVILLE NCMN RM 5.                                      
         


001540*10*8889RTN401058W1044334 1519M         COWELD                  
         
001550*13*PLATTEVILLE NCMN RM 3                            C  0000    
         
001560*20*A/NGS                 1981     A/NGS                
19911119EAR  G   
001570*26*07/                                DR N C  NGS              
         
001580*28*PLATTEVILLE NCMN NO 3 1981                                  
         
001590*30*THE STATION IS LOCATED ABOUT 9.5 KM (5.9 MI) SOUTHEAST OF
PLATTEVILLE,
001600*30*AT THE PLATTEVILLE RADAR SITE, IN THE CENTER OF SECTION 36, 
T 3 N, R 
001610*30*66 W.  OWNERSHIP--US DEPARTMENT OF COMMERCE, NATIONAL
COMMUNICATIONS  
001620*30*AND INFORMATION ADMINISTRATION, NOAA, WPL, REWP 4, 325
BROADWAY,      
001630*30*BOULDER, CO 80303.  PHONE IS 303-497-6385 FOR COMBINATION
TO GATE     
001640*30*LOCK.                                                       
         
001650*30*TO REACH FROM THE JUNCTION OF US HIGHWAY 85 AND STATE
HIGHWAY 66 AT   
001660*30*THE SOUTH END OF PLATTEVILLE, GO SOUTH ON HIGHWAY 85 FOR
2.05 KM      
001670*30*(1.27 MI) TO A CROSSROAD.  TURN LEFT, EAST, ON GRAVEL ROAD
(ROAD 28)  
001680*30*FOR 7.20 KM (4.47 MI) TO THE ROAD END AT A THREE-WAY FORK
AND A       
001690*30*LOCKED GATE ON THE MIDDLE ROAD.  PASS THROUGH GATE AND GO
SOUTHEAST   
001700*30*ON GRADED ROAD FOR 1.01 KM (0.63 MI) TO A GRAVEL ROAD LEFT
JUST       
001710*30*BEFORE REACHING MAIN BUILDING AND THE STATION ON THE RIGHT. 
         
001720*30*THE STATION IS A REFERENCE MARK DISK SET IN THE TOP OF A
30-CM        
001730*30*CONCRETE POST PROJECTING 5 CM, AND WITH A WOODEN STAND. 
LOCATED 53.4 
001740*30*M (175.2 FT) SOUTH-SOUTHWEST OF THE ROAD CENTER, 5.8 M
(19.0 FT) WEST 
001750*30*OF A WIRE FENCE LINE, 1.2 M (3.9 FT) NORTH OF A LONE METAL
FENCE      
001760*30*POST, 1.05 M (3.44 FT) EAST-SOUTHEAST OF A FIBERGLASS
WITNESS POST,   
001770*30*AND 62 M (203.4 FT) SOUTHEAST OF NGS MARK PLATTEVILLE NCMN. 
         



                                3-15
001780*10*8890D N401058W104433101522M         COWELD                P 
         
001790*13*PLATTEVILLE NCMN RM 5                            P  0000    
         
001800*20*A/NGS                 1991RSC   /                           
         
001820*26*07/                                DH N B  NGS              
         
001820*28*PLATTEVILLE NCMN NO 5 1991                                  
         
001830*30*STATION IS LOCATED ABOUT 9.5 KM (5.9 MI) SOUTHEAST OF
PLATTEVILLE, AT 
001840*30*THE NOAA PLATTEVILLE RADAR SITE, ABOUT 75 M (246.1 FT)
NORTHWEST OF   
001850*30*THE MAIN BUILDING, ON THE EAST SIDE OF A GRADED AREA WITH
SEVERAL     
001860*30*CONCRETE PADS USED FOR PLATE TECTONICS SURVEY VEHICLES, IN
THE CENTER 
001870*30*OF SECTION 36, T 3 N, R 66 W.  OWNERSHIP--US DEPARTMENT OF
COMMERCE,  
001880*30*NATIONAL COMMUNICATIONS AND INFORMATION ADMINISTRATION,
NOAA, WPL,    
001890*30*REWP 4, 325 BROADWAY, BOULDER, CO 80303.  CALL 303-497-6385
FOR       
001900*30*COMBINATION TO LOCKED GATE.                                 
         
001910*30*TO REACH FROM THE JUNCTION OF US HIGHWAY 85 AND STATE
HIGHWAY 66 AT   
001920*30*THE SOUTH END OF PLATTEVILLE, GO SOUTH ON HIGHWAY 85 FOR
2.05 KM      
001930*30*(1.27 MI) TO A CROSSROAD.  TURN LEFT, WEST, ON GRAVEL ROAD
(ROAD 28)  
001940*30*FOR 7.20 KM (4.47 MI) TO ROAD END AT THREE-WAY FORK AND A
LOCKED GATE 
001950*30*ON THE MIDDLE ROAD.  PASS THROUGH GATE, SOUTHEAST, ON
GRADED ROAD FOR 
001960*30*1.01 KM (0.63 MI) TO A GRAVEL ROAD LEFT JUST BEFORE
REACHING THE MAIN 
001970*30*BUILDING.  TURN LEFT, NORTHEAST, FOR 25 M (82.0 FT) TO THE
STATION ON 
001980*30*THE RIGHT.                                                  
         
001990*30*STATION MARK IS SET IN THE TOP OF A 0.5 M (1.6 FT) ROUND
CONCRETE POST
002000*30*ENCASED IN A PVC PIPE PROJECTING 1.6 M (5.2 FT) ABOVE
GROUND FROM A 1 
002010*30*M (3.3 FT) CONCRETE BASE SET 3.4 M (11.2 FT) INTO THE
GROUND.  A      
002020*30*PERMANENT ROUND TRIBRACH WITH THREADBOLT IS CENTERED ON THE
POST.  IT 
002030*30*IS 29.6 M (97.1 FT) NORTHEAST OF THE ROAD CENTER, 22.9 M
(75.1 FT)    
002040*30*NORTH-NORTHEAST OF A TELEPHONE PEDESTAL, 19.5 M (64.0 FT)
WEST OF THE 
002050*30*WEST CORNER OF A FENCE AROUND AN ELECTRIC SUBSTATION, 15.0
M          
002060*30*(49.2 FT) SOUTHEAST OF THE SOUTHEAST CORNER OF ELECTRIC BOX
75, 49.4  
002070*30*M (162.1 FT) SOUTHEAST OF NGS MARK PLATTEVILLE NCMN.        
         
002080*AA*


If you need more information regarding the writing or use of
descriptions, or need clarification of code sets or practices,
contact the National Geodetic Information Center by calling (301)
713-3242, or at the following address:
        

        NOAA
        National Geodetic Survey, N/CG174
        1315 East-West Highway
        Silver Spring, Maryland
        20910-3282


THE FOLLOWING PAGES INCLUDE DETAILED EXAMPLES (FORMAT DIAGRAMS) FOR
EACH CHARACTER FIELD AND THE PROPER LOCATION AND LENGTH OF THE FIELD
WITHIN A GIVEN RECORD.




                                3-16
GEODDESCDATASETRECORDS


          DATA SET IDENTIFICATION RECORD
 
 1         6   7     10 11     14 15     18 19         24   25                               
     44    
Ŀ Ŀ Ŀ Ŀ Ŀ  
Ŀ
      

  SEQUENCE       JOB      DATA      DATA    ORGANIZATION          SUBMITTING ORGANIZATION
NAME
   NUMBER        CODE     CLASS     TYPE       SYMBOL                           
                         (GEOD)    (DESC)   (See Annex C)
 
           45                                         66       73             80
           Ŀ       Ŀ
                  
              SUBMITTING ORGANIZATION NAME CONTINUED            Y Y Y Y M M D D 
                                                               FILE CREATION DATE
--------------------------------------------------------------------------------------------
-------------
          *00* PROJECT INFORMATION RECORD
 
 1         6       7     10    11             18   19     22   23                            
      41
Ŀ     Ŀ    Ŀ   Ŀ  
Ŀ
              

  SEQUENCE          DATA           ACCESSION       LINE/PART                    BLANK
   NUMBER           CODE            NUMBER          NUMBER

                       42                                                                    
      80
                      
Ŀ  
                      
  
                                                            BLANK
--------------------------------------------------------------------------------------------
-------------
          *01* PROJECT TITLE RECORD
 
 1         6       7     10    11                                                            
      45  
Ŀ     Ŀ   
Ŀ
        

  SEQUENCE          DATA                                     PROJECT TITLE
   NUMBER           CODE       46                                                            
      80
                              
Ŀ
                              

                                                       PROJECT TITLE (CONTINUED)
--------------------------------------------------------------------------------------------
-------------
 
                                            3-17
GEODDESCDATA-SET-RECORDS
(CONT)

          *02*, *03*, *04* PROJECT TITLE CONTINUATION RECORDS

 1         6       7     10    11                                                            
      45  
Ŀ     Ŀ   
Ŀ
        

  SEQUENCE          DATA                               PROJECT TITLE CONTINUATION
   NUMBER           CODE       46                                                            
      80
                              
Ŀ
                              

                                                       PROJECT TITLE CONTINUATION
--------------------------------------------------------------------------------------------
-------------

          *05* COMMENT RECORD
 
 1         6       7    10     11                                                            
      45
Ŀ     Ŀ   
Ŀ
        

  SEQUENCE          DATA                                         COMMENT
   NUMBER           CODE       46                                                            
        80
                              
Ŀ
                              

                                                           COMMENT (CONTINUED)
--
--------------------------------------------------------------------------------------------
-----------
          *10* STATION LOCATION RECORD

 1         6    7     10  11     14  15        16       17           23   24             31  
32       36 
Ŀ  Ŀ  Ŀ  Ŀ       Ŀ      Ŀ   Ŀ  
Ŀ 
                        

   SEQUENCE      DATA        SSN     D/R    RECOVERY     H D D M M S S     W D D D M M S S   
APPROXIMATE
    NUMBER       CODE               CODE      TYPE        APPROXIMATE       APPROXIMATE      
   HEIGHT
                                              CODE         LATITUDE          LONGITUDE      

                                                        (E.G. N382443)     (E.G. W1023452) 

   37       39           45  47 48  49                                     68  69     72  73 
       78
   Ŀ      Ŀ  Ŀ  Ŀ  Ŀ 
Ŀ
                

 HEIGHT     30 MINUTE QUAD   STATE   COUNTY NAME                              APPLICATION    
 PID 
  UNITS       IDENTIFIER                                                         CODES      
-
--------------------------------------------------------------------------------------------
------------

                                            3-18
GEODDESCDATA-SET-RECORDS
(CONT)

          *13* STATION IDENTIFICATION RECORD
 
  1         6    7     10  11                                                                
    46
 Ŀ  Ŀ 
Ŀ
    

    SEQUENCE      DATA      STATION DESIGNATION
     NUMBER       CODE
 
    47     50            52 53             55             57 58              60           
63     66
    Ŀ            Ŀ             Ŀ            Ŀ              Ŀ          
Ŀ
                                                                 

CONT. DESIGNATION     UNDERGROUND      UNDERGROUND     UNDERGROUND     TRANSPORTATION     
PACK TIME
                      MARKER TYPE     MAGNETIC CODE    SETTING CODE         CODE
--------------------------------------------------------------------------------------------
-------------

          *15* ALIAS RECORD
 
 1         6   7     10 11                                                                   
         50
Ŀ Ŀ
Ŀ
 

  SEQUENCE      DATA     ALIAS
   NUMBER       CODE
--------------------------------------------------------------------------------------------
-------------

          *20* MONUMENTED/RECOVERED RECORD
 
 1         6    7     10     11      13         18                          32  33     36 
37   39
Ŀ  Ŀ     Ŀ     Ŀ  Ŀ 
Ŀ
               

   SEQUENCE      DATA      SETTING       SETTING AGENCY SYMBOL / NAME             YEAR    
CHIEF OF 
    NUMBER       CODE      AGENCY                                                 SET      
PARTY 
                         GROUP CODE
                                 
   42         44         49                          63   64             71   72   74       
77
   Ŀ        Ŀ   Ŀ   Ŀ       
Ŀ
                        

RECOVERING     RECOVERING AGENCY SYMBOL / NAME             Y Y Y Y M M D D    CHIEF OF    
RECOVERY
 AGENCY                                                    DATE RECOVERED    RECOVERING   
CONDITION
GROUP CODE                                                                     PARTY        
CODE
--------------------------------------------------------------------------------------------
-------------
                                            3-19
GEODDESCDATA-SET-RECORDS
(CONT)

          *26* SETTING RECORD
 
 1         6     7     10   11 12   14                                                       
     45
Ŀ   Ŀ   Ŀ  
Ŀ
        

  SEQUENCE        DATA     SETTING   SPECIFIC SETTING PHRASE
   NUMBER         CODE      CODE

  46 47        49             51            54         59                                    
 79
  Ŀ        Ŀ            Ŀ          
Ŀ
                                

 MARKER      MAGNETIC      VERTICAL          INSCRIBED AGENCY SYMBOL / NAME
  TYPE         CODE        STABILITY                                        
                         OVERRIDE CODE                     
--------------------------------------------------------------------------------------------
-------------

          *28* STAMPING RECORD
 
   1         6    7     10  11                                                         40
  Ŀ  Ŀ  Ŀ
      
     SEQUENCE      DATA      STAMPING
      NUMBER       CODE

  41                                      60
  Ŀ
  
   STAMPING CONTINUED
-
--------------------------------------------------------------------------------------------
------------
 
          *29* ROD/PIPE RECORD (OPTIONAL)
 
   1         6    7     10   11     12 13   14     17   18     21     22              23 24
  Ŀ  Ŀ   Ŀ    Ŀ   Ŀ   Ŀ     Ŀ             Ŀ
                                   
    SEQUENCE       DATA     UNITS  SETTING  ROD/PIPE     SLEEVE     R=RECESS      
PROJECTION OR
     NUMBER        CODE     CODE    CODE     DEPTH       DEPTH      F=FLUSH         RECESS
OF
                           (E OR M)                                 P=PROJECTING      CASING
--------------------------------------------------------------------------------------------
-------------

                                            3-20

GEODDESCDATA-SET-RECORDS
(CONT)

          *30* TEXT RECORDS
 
   1         6    7     10   11                                                              
        47
  Ŀ  Ŀ  
Ŀ
      

    SEQUENCE       DATA       DESCRIPTIVE TEXT
     NUMBER        CODE 
    
  48                                                               80
  Ŀ
  
             DESCRIPTIVE TEXT CONTINUED
--------------------------------------------------------------------------------------------
-------------

  DATA SET TERMINATION RECORD
 
 1         6    7     10   11                                                                
      80
Ŀ  Ŀ  
Ŀ        
    
           
SEQUENCE       DATA                                          BLANK                  
   NUMBER        CODE
 (INC BY 10) 
--------------------------------------------------------------------------------------------
-------------
















                                            3-21



















                       INTENTIONALLY BLANK

































                              3-22

                               ANNEX A

                     NGS STATE AND COUNTRY CODES


NORTH AMERICAN AND GREENLAND

   GREENLAND . . . . . . . . . . GL

   CANADA  . . . . . . . . . . . CD

       Provinces and Territories:

       Alberta . . . .  AB    Newfoundland . . . NF      Prince
                                                         Edward Is
                                                         PE
       British Columbia BC    Northwest Terr's . NW      Quebec . .
                                                         . . . PQ
       Manitoba . . . . MB    Nova Scotia . . .  NS      Saskatchewa
                                                         n . . SK
       New Brunswick  . NB    Ontario . . . . .  ON      Yukon
                                                         Territory 
                                                         YK

   UNITED STATES . . . . . . US

       States and District of Columbia:

       Alabama . . . .  AL    Kentucky . . . . . KY      North
                                                         Dakota . .
                                                         ND
       Alaska  . . . .  AK    Louisiana  . . . . LA      Ohio . . .
                                                         . . . OH
       Arizona . . . .  AZ    Maine  . . . . . . ME      Oklahoma .
                                                         . . . OK
       Arkansas  . . .  AR    Maryland . . . . . MD      Oregon . .
                                                         . . . OR
       California  . .  CA    Massachusetts  . . MA      Pennsylvani
                                                         a . . PA
       Colorado .  . .  CO    Michigan . . . . . MI      Rhode
                                                         Island . .
                                                         RI
       Connecticut . .  CT    Minnesota  . . . . MN      South
                                                         Carolina .
                                                         NC
       Delaware  . . .  DE    Mississippi  . . . MS      South
                                                         Dakota . .
                                                         SD
       Dist of Columbia DC    Missouri . . . . . MO      Tennessee 
                                                         . . . TN
       Florida . . . .  FL    Montana  . . . . . MT      Texas  . .
                                                         . . . TX
       Georgia . . . .  GA    Nebraska . . . . . NE      Utah . . .
                                                         . . . UT
       Hawaii  . . . .  HI    Nevada . . . . . . NV      Vermont  .
                                                         . . . VT
       Idaho . . . . .  ID    New Hampshire  . . NH      Virginia .
                                                         . . . VA
       Illinois  . . .  IL    New Jersey . . . . NJ      Washington
                                                         . . . WA
       Indiana . . . .  IN    New Mexico . . . . NM      West
                                                         Virginia  .
                                                         WV
       Iowa  . . . . .  IA    New York . . . . . NY      Wisconsin 
                                                         . . . WI
       Kansas  . . . .  KS    North Carolina . . NC      Wyoming  .
                                                         . . . WY

       Other Political  Units and Territories:

       American Samoa . . . . . AS         Navassa Island . . . . .
                                           . . . . BQ
       Guam . . . . . . . . . . GU         Johnston Atoll . . . . .
                                           . . . . JQ
       Puerto Rico  . . . . . . PR         Midway Islands . . . . .
                                           . . . . MQ
       Virgin Islands . . . . . VI         Wake Island  . . . . . .
                                           . . . . WQ
       Trust Terr of Pacific Islands (Marianas, Carolines,
Marshalls) . . . TQ

   BERMUDA . . . . . . . .  BD

   MEXICO  . . . . . . . .  MX

                                 A-1

CENTRAL AMERICA AND THE CARIBBEAN AREA

                                              
   BAHAMA ISLANDS  . . . . . . . BS     HAITI  . . . . . . . . . . .
                                        . HA
   BARBADOS  . . . . . . . . . . BB     HONDURAS . . . . . . . . . .
                                        . HO
   BELIZE (British Honduras) . . BH     JAMAICA  . . . . . . . . . .
                                        . JM
   CAYMAN ISLANDS  . . . . . . . CJ     NETHERLANDS ANTILLES . . . .
                                        . NA
   COLOMBIA  . . . . . . . . . . CB     NICARAGUA  . . . . . . . . .
                                        . NI
   COSTA RICA  . . . . . . . . . CR     PANAMA . . . . . . . . . . .
                                        . PN
   CUBA  . . . . . . . . . . . . CU     TRINIDAD AND TOBAGO  . . . .
                                        . TD
   DOMINICAN REPUBLIC  . . . . . DR     TURKS AND CAICOS ISLANDS . .
                                        . TC
   EL SALVADOR . . . . . . . . . ES     VENEZUELA  . . . . . . . . .
                                        . VE
   GUATEMALA . . . . . . . . . . GT


OTHER COUNTRIES OR AREAS OF INTEREST TO NGS


   ANTARCTICA  . . . . . . . . . AY     NORWAY . . . . . . . . . . .
                                        . NO
   ARGENTINA . . . . . . . . . . AJ     PARAGUAY . . . . . . . . . .
                                        . PY
   BOLIVIA . . . . . . . . . . . BL     PHILIPPINE ISLANDS . . . . .
                                     . PH
   BRAZIL  . . . . . . . . . . . BR     SAINT HELENA ISLANDS . . . .
                                        . SH
   CENTRAL AFRICAN REPUBLIC  . . CF     SAUDI ARABIA . . . . . . . .
                                        . SA
   CHILE   . . . . . . . . . . . CI     SOUTH AFRICA . . . . . . . .
                                        . SF
   ECUADOR . . . . . . . . . . . EC     SOVIET UNION . . . . . . . .
                                        . UR
   EGYPT   . . . . . . . . . . . EG     SUDAN  . . . . . . . . . . .
                                        . SU
   ETHIOPIA  . . . . . . . . . . ET     SURINAM  . . . . . . . . . .
                                        . SR
   FRENCH GUIANA . . . . . . . . FG     TANZANIA . . . . . . . . . .
                                        . TZ
   FRENCH SOMALILAND . . . . . . FS     UGANDA . . . . . . . . . . .
                                        . UG
   ICELAND . . . . . . . . . . . IC     URUGUAY  . . . . . . . . . .
                                        . UY
   ITALY . . . . . . . . . . . . IT     ZAMBIA . . . . . . . . . . .
                                        . ZA
   JAPAN . . . . . . . . . . . . JA




















                                 A-2
                               ANNEX B

              STATE PLANE COORDINATES (SPC) ZONE CODES 


    SPC ZONE  CODE           SPC ZONE  CODE           SPC ZONE  CODE

    AL  E   0101             HI  1   5101             MN  N   2201
        W   0102                 2   5102                 C   2202
                             3   5103                 S   2203
    AK  1   5001                 4   5104             
        2   5002                 5   5105             MS  E   2301
        3   5003                                      W   2302
        4   5004             ID  E   1101                 
        5   5005                 C   1102             MO  E   2401
        6   5006                 W   1103                 C   2402
        7   5007                                      W   2403
        8   5008             IL  E   1201             
        9   5009                 W   1202             MT      2500
        10  5010
                         IN  E   1301
    AZ  E   0201                 W   1302
        C   0202                                  NE      2600
        W   0203             IA  N   1401
                             S   1402
    AR  N   0301                                  NV  E   2701
        S   0302             KS  N   1501                 C   2702
                             S   1502                 W   2703
    CA  1   0401
        2   0402             KY  N   1601             NH      2800
        3   0403                 S   1602
        4   0404                                  NJ      2900
        5   0405             LA  N   1701
        6   0406                 S   1702             NM  E   3001
                             SH  1703                 C   3002
    CO  N   0501                                      W   3003
        C   0502             ME  E   1801
        S   0503                 W   1802             NY  E   3101
                                                  C   3102
    CT      0600             MD      1900                 W   3103
                                                  L   3104
    DE      0700             MA  M   2001
                             I   2002             NC      3200
    FL  E   0901
        W   0902             MI  N   2111             ND  N   3301
        N   0903                 C   2112                 S   3302
                             S   2113
    GA  E   1001                                  OH  N   3401
        W   1002                                      S   3402




                                 B-1

    SPC ZONE  CODE           SPC ZONE  CODE           SPC ZONE  CODE

    OK  N   3501             TX  N   4201             WV  N   4701
        S   3502                 NC  4202                 S   4702
                             C   4203
    OR  N   3601                 SC  4204             WI  N   4801
        S   3602                 S   4205                 C   4802
                                                  S   4803
    PA  N   3701             UT  N   4301
        S   3702                 C   4302             WY  E   4901
                             S   4303                 EC  4902
    RI      3800                                      WC  4903
                         VT      4400                 W   4904
    SC      3900
                         VA  N   4501             PR & VI 5200
    SD  N   4001                 S   4502
        S   4002                                      AS  5300
                         WA  N   4601
    TN      4100                 S   4602                 GU  5400





    LEGEND:

    C   - Central Zone
    E   - Eastern Zone
    L   - Long Island Zone (NY)
    M   - Mainland Zone (MA)
    N   - Northern Zone
    NC  - North-Central Zone(TX)
    SH  - Offshore Zone (LA)
    S   - Southern Zone
    SC  - South-Central Zone (TX)
    W   - Western Zone
    I   - Island (MA)


    Note: A blank in the zone columns above
           indicates that the state has only
           one state plane coordinate zone.










                                 B-2


                               ANNEX C

                CONTRIBUTORS OF GEODETIC CONTROL DATA


This ANNEX contains a list of organizations which have contributed
(or are expected to contribute) data resulting from geodetic control
established to
extend and/or densify the national horizontal and vertical geodetic
control networks.

A unique six-character identification symbol has been assigned to
each
organization listed.  As far as possible, this symbol is identical
to the
commonly used abbreviation or acronym of the respective
organization.  However,
to ensure uniqueness, modifications of the commonly used abbre-
viations and acronyms, as well as arbitrary symbols, had to be
assigned in many cases.  Organizations not listed in this ANNEX may
contact the National Geodetic Survey
(see ANNEX K) to have a unique identification symbol assigned.

The respective organizations are grouped under 13 categories, and
within each category they are listed in the alphabetic order of
their identification
symbols.  The 13 categories are given in the index below.

CATEGORIES OF CONTRIBUTORS OF GEODETIC CONTROL DATA              
                                                              PAGE

    A.  National Agencies . . . . . . . . . . . . . . . . . . . . .
    C-3
    B.  Inter-State or Inter-Province Agencies  . . . . . . . . . .
    C-4
    C.  State, Province, Commonwealth, and Territorial Agencies . .
    C-5
    D.  County Agencies . . . . . . . . . . . . . . . . . . . . . .
    C-9
    E.  Municipal Agencies (Cities) . . . . . . . . . . . . . . . .
    C-15
    F.  Inter-City and Inter-County Agencies  . . . . . . . . . . .
    C-20
    G.  Railroads . . . . . . . . . . . . . . . . . . . . . . . . .
    C-22
    H.  Utility and Natural Resource Companies  . . . . . . . . . .
    C-23
    I.  Surveying, Engineering, and Construction Industry . . . . .
    C-25
    J.  Educational Institutions  . . . . . . . . . . . . . . . . .
    C-29
    K.  Professional and Amateur Associations . . . . . . . . . . .
    C-30
    L.  Miscellaneous Commercial or Private Firms . . . . . . . . .
    C-30
    M.  Non-Specific Designators  . . . . . . . . . . . . . . . . .
    C-31


CONVENTIONS USED IN THE FORMATION OF IDENTIFICATION SYMBOLS

    a.  State, Province, Commonwealth, and Territorial Agencies: 
    The six-
character identification symbol of a state, province, commonwealth,
or
territorial agency consists of the respective two-character state
code
(see ANNEX A) to which up to four letters (e.g. the initials of the
agency's
name) may be appended.  In general, "S" for "state" and "0" for "of"
should
be omitted.






                                 C-1
    b.  County Agencies:  The six-character identification symbol of
    a county
agency consists of the two-character code denoting the state in
which the county is located (see ANNEX A) followed by a hyphen and
by a three-digit number which has been assigned to the respective
county in Worldwide Geographic Location
Codes prepared by the Office of Finance, General Services
Administration (GSA), September 1987.  Agencies which do not have
access to this publication may
contact the National Geodetic Survey (see ANNEX K) to obtain the
appropriate
county code.    

    c.  City Agencies:  The six-character identification symbol of a
    city agency
consists of the two-character code denoting the state in which the
city is
located (see ANNEX A) followed by a four-digit number which has been
assigned to
the respective city in Worldwide Geographic Location Codes prepared
by the
Office of Finance, General Services Administration (GSA), September
1987.
Agencies which do not have access to this publication may contact
the National Geodetic Survey (see ANNEX K) to obtain the appropriate
city code.
                                                      
NOTE:  For the purposes of this ANNEX, agencies of independent
cities which are also counties or county-equivalents should be
considered to be city (rather than county) agencies and assigned
identification symbols accordingly.



                                                      































                                 C-2
*****************************************                        
****************
* CONTRIBUTORS OF GEODETIC CONTROL DATA *                         *
AS OF 940131 *
*****************************************                        
****************

 ͻ
 NOTE : AGENCY SYMBOLS LISTED HEREIN ARE FOR NGS INTERNAL USE ONLY
 ͼ

                          NATIONAL AGENCIES

SYMBOL      FULL NAME
******      ********************************************************
            *******
AEC    ATOMIC ENERGY COMMISSION (NOW ERDA)
AMS    US ARMY MAP SERVICE (NOW DMA)
BLM    US BUREAU OF LAND MANAGEMENT
BOF    US BUREAU OF COMMERCIAL FISHERIES
BOM    US BUREAU OF MINES
BOR    US BUREAU OF RECLAMATION (NOW WPRS)
BPR    US BUREAU OF PUBLIC ROADS
BV     BRITISH VIRGIN ISLAND
CAB    CIVIL AERONAUTICS BOARD
CGS    US COAST AND GEODETIC SURVEY (NOW NOS)
CHS    CANADIAN HYDROGRAPHIC SERVICE
DI     US DEPARTMENT OF INTERIOR
DMA    DEFENSE MAPPING AGENCY
DOD    US DEPARTMENT OF DEFENSE
DTENAL      ESTUDIOS DEL TERRITORIO NACIONAL DE MEXICO
ES-IGN      EL SALVADOR-INST GEOG NAC
FAA    FEDERAL AVIATION ADMINISTRATION
FHWA   FEDERAL HIGHWAY ADMINISTRATION
GSC    GEODETIC SURVEY OF CANADA
GSFC   GODDARD SPACE FLIGHT CENTER
IAGS   INTER-AMERICAN GEODETIC SURVEY
IBC    INTERNATIONAL BOUNDARY COMMISSION
IBWC   INTERNATIONAL BOUNDARY AND WATER COMMISSION
INEGI  INSTITUTO NACIONAL DE ESTADISTICA GI DE MEXICO
IWC    INTERNATIONAL WATERWAYS COMMISSION
NASA   NATIONAL AERONAUTICS AND SPACE ADMIN
NBS    NATIONAL BUREAU OF STANDARDS (NOW NIST)
NGS    NATIONAL GEODETIC SURVEY
NIH    NATIONAL INSTITUTES OF HEALTH
NIST   NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
NOS    NATIONAL OCEAN SURVEY
NOSAMC      NOS ATLANTIC MARINE CENTER
NOSOES      NOS OFFICE OF OCEAN AND EARTH SCIENCES
NOSOMA      NOS OCEANOGRAPHY AND MARINE ASSESSMENT
NOSPMC      NOS PACIFIC MARINE CENTER
NPS    NATIONAL PARK SERVICE
NSL    US NAVY STANDARDS LABORATORY AT POMONA
ONCADH      ONTARIO CANADA DEPARTMENT OF HIGHWAYS
PBPP   OFFICE OF PUBLIC BUILDINGS AND PUBLIC PARKS
PICGS  PHILIPPINE COAST AND GEODETIC SURVEY
SCS    SOIL CONSERVATION SERVICE


                                 C-3
                    NATIONAL AGENCIES - CONTINUED

SYMBOL      FULL NAME
******      ********************************************************
            *******
SWEDLS      SWEDISH LAND SURVEY
TPC    US ARMY TOPOGRAPHIC COMMAND (NOW DMA)
TVA    TENNESSEE VALLEY AUTHORITY
USA    US ARMY
USAF   US AIR FORCE                 
USCG   US COAST GUARD
USDA   US DEPARTMENT OF AGRICULTURE
USDOT  US DEPARTMENT OF TRANSPORTATION
USDWC  US DEEP WATERWAY COMMISSION
USE    US ARMY CORPS OF ENGINEERS
USFS   US FOREST SERVICE
USFWA  US FEDERAL WORKS AGENCY
USFWS  US FISH AND WILDLIFE SERVICE
USGLO  US GOVERNMENT LAND OFFICE
USGS   US GEOLOGICAL SURVEY
USGS-E      USGS EASTERN MAPPING CENTER
USGS-M      USGS MID-CONTINENT MAPPING CENTER
USGS-R      USGS ROCKY MOUNTAIN MAPPING CENTER
USGS-W      USGS WESTERN MAPPING CENTER
USIIS  US INDIAN IRRIGATION SERVICE
USLHS  US LIGHTHOUSE SERVICE (NOW USCG)
USLS   US LAKE SURVEY
USMC   US MARINE CORPS
USN    US NAVY
USPS   US POSTAL SERVICE
USSC   US SUPREME COURT
USTD   US TREASURY DEPARTMENT
USWB   US WEATHER BUREAU (NOW NWS)
VI     VIRGIN ISLANDS (US)
VICS   VIRGIN ISLANDS CADASTRAL SURVEY
WPA    WORKS PROGRESS ADMINISTRATION
WPRS   US WATER AND POWER RESOURCES SERVICE
WSMR   WHITE SANDS MISSILE RANGE


               INTER-STATE OR INTER-PROVINCE AGENCIES 

SYMBOL      FULL NAME
******
****************************************************************
BPA    BONNEVILLE POWER ADMINISTRATION
CGS+SS      US COAST AND GEODETIC SURVEY AND STATE SURVEY
DEPABC      DELAWARE-PENNSYLVANIA BOUNDARY COMMISSION
IRC    ILLINOIS RIVER COMMISSION
MDDEBC      MARYLAND-DELAWARE BOUNDARY COMMISSION
MDVABC      MARYLAND-VIRGINIA BOUNDARY COMMISSION
MENHBC      MAINE-NEW HAMPSHIRE BOUNDARY COMMISSION
MORC   MISSOURI RIVER COMMISSION
MRC    MISSISSIPPI RIVER COMMISSION
NMTXBC      NEW MEXICO AND TEXAS BOUNDARY COMMISSION
VTNHBC      VERMONT-NEW HAMPSHIRE BOUNDARY COMMISSION

                                 C-4
       STATE, PROVINCE, COMMONWEALTH, AND TERRITORIAL AGENCIES

SYMBOL      FULL NAME
******      ********************************************************
            *******
AKDAVI      ALASKA DIVISION OF AVIATION
AKDLS  ALASKA DIVISION OF LAND SURVEY
AKDNR  ALASKA DEPARTMENT OF NATURAL RESOURCES
AKHD   ALASKA HIGHWAY DEPARTMENT
AKPWR  ALASKA POWER ADMINISTRATION
ALGS   ALABAMA GEODETIC SURVEY
ALHD   STATE OF ALABAMA HIGHWAY DEPARTMENT
ARGLS  ARKANSAS GEOLOGICAL SURVEY
ARGS   ARKANSAS GEODETIC SURVEY
ARHD   ARKANSAS STATE HIGHWAY DEPARTMENT
AZDT   ARIZONA DEPARTMENT OF TRANSPORTATION
AZHD   ARIZONA HIGHWAY DEPARTMENT (NOW AZDT)
CADC    CALIFORNIA DEPARTMENT OF CONSERVATION
CADF    CALIFORNIA DIVISION OF FORESTRY
CADH    CALIFORNIA DIVISION OF HIGHWAYS (NOW CADT)       
CADPW   CALIFORNIA DEPARTMENT OF PUBLIC WORKS            
CADT    CALIFORNIA DEPARTMENT OF TRANSPORTATION          
CADWR   CALIFORNIA DEPARTMENT OF WATER RESOURCES         
CAEC    CALIFORNIA EARTHQUAKE COMMISSION                 
CAGS    CALIFORNIA GEODETIC SURVEY                       
CASLC   CALIFORNIA STATE LANDS COMMISSION                
CASPC   CALIFORNIA STATE PARKS COMMISSION                
CODH    COLORADO STATE DEPARTMENT OF HIGHWAYS            
CODOT   COLORADO DEPARTMENT OF TRANSPORTATION            
COGS    COLORADO GEODETIC SURVEY                         
CTCSF   CONNECTICUT COMMISSION OF SHELL FISHERIES        
CTDT    CONNECTICUT DEPARTMENT OF TRANSPORTATION         
CTGS    CONNECTICUT GEODETIC SURVEY                      
DCDHT   DC DEPARTMENT OF HIGHWAYS AND TRAFFIC            
DEDHT   DELAWARE DEPARTMENT OF HIGHWAYS AND TRANSP       
FLDACS  FLORIDA DEPARTMENT OF AGR AND CONSUMER SERV      
FLDNR   FLORIDA DEPARTMENT OF NATURAL RESOURCES          
FLDPW   FLORIDA DEPARTMENT OF PUBLIC WORKS               
FLDT    FLORIDA DEPARTMENT OF TRANSPORTATION             
FLGS    FLORIDA GEODETIC SURVEY                          
FLHD    FLORIDA HIGHWAY DEPARTMENT (NOW FLDT)            
GADT    GEORGIA DEPARTMENT OF TRANSPORTATION             
GAGS    GEORGIA GEODETIC SURVEY                          
GAHD    GEORGIA HIGHWAY DEPARTMENT (NOW GADT)            
HIDT    HAWAII DEPARTMENT OF TRANSPORTATION              
HIGS    HAWAII GEODETIC SURVEY                           
HITS    HAWAII TERRITORIAL SURVEY                        
IACC    IOWA CONSERVATION COMMISSION                     
IAHD    IOWA HIGHWAY DEPARTMENT                          
IDDH    IDAHO DEPARTMENT OF HIGHWAYS (NOW IDDT)          
IDDT    IDAHO DEPARTMENT OF TRANSPORTATION (NOW IDTD)    
IDGS    IDAHO GEODETIC SURVEY                            
IDPWD   IDAHO DEPARTMENT OF PUBLIC WORKS                 
IDTD    IDAHO TRANSPORTATION DEPARTMENT                  
ILDPW   ILLINOIS DEPARTMENT OF PUBLIC WORKS             

                                 C-5
 STATE, PROVINCE, COMMONWEALTH, AND TERRITORIAL AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
ILDT    ILLINOIS DEPARTMENT OF TRANSPORTATION            
ILDW    ILLINOIS DIVISION OF WATERWAYS                   
ILGS    ILLINOIS GEODETIC SURVEY                         
ILHD    ILLINOIS HIGHWAY DEPARTMENT (NOW ILDT)           
ILSC    ILLINOIS SANITARY COMMISSION                     
INDNR   INDIANA DEPARTMENT OF NATURAL RESOURCES          
INFCC   INDIANA FLOOD CONTROL AND WATER RES COMM         
INGS    INDIANA GEODETIC SURVEY                          
INHD    INDIANA HIGHWAY DEPARTMENT                       
IOWAGS  IOWA GEODETIC SURVEY                             
KSDT    KANSAS DEPARTMENT OF TRANSPORTATION              
KSGS    KANSAS GEODETIC SURVEY                           
KSHC    STATE HIGHWAY COMM OF KANSAS (NOW KSDT)          
KSWRB   KANSAS WATER RESOURCES BOARD                     
KYDT    KENTUCKY DEPARTMENT OF TRANSPORTATION            
KYGS    KENTUCKY GEODETIC SURVEY                         
KYHD    KENTUCKY STATE HIGHWAY DEPARTMENT (NOW KYDT)     
LADH    LOUISIANA DEPARTMENT OF HIGHWAYS (NOW LADTD)     
LADPW   LOUISIANA DEPARTMENT OF PUBLIC WORKS             
LADTD   LOUISIANA DEPT OF TRANSP AND DEVELOPMENT         
LAGS    LOUISIANA GEODETIC SURVEY                        
LASCC   LOUISIANA STATE CONSERVATION COMMISSION          
MADLH   MASSACHUSETTS DEPARTMENT OF LAND AND HARBORS     
MADPW   MASSACHUSETTS DEPARTMENT OF PUBLIC WORKS         
MALCT   MASSACHUSETTS LAND COURT
MAGS    MASSACHUSETTS GEODETIC SURVEY                    
MDBCSM  MARYLAND BUREAU OF CONTROL SURVEYS AND MAPS      
MDDNR   MARYLAND DEPARTMENT OF NATURAL RESOURCES         
MDDT    MARYLAND DEPARTMENT OF TRANSPORTATION            
MDGS    MARYLAND GEODETIC SURVEY                         
MDSFC   MARYLAND SHELL FISHERIES COMMISSION              
MDSHA   MARYLAND DOT STATE HIGHWAY ADMINISTRATION        
MDSRC   MARYLAND STATE ROADS COMMISSION (NOW MDDT)       
MEDT    MAINE DEPARTMENT OF TRANSPORTATION               
MEGS    MAINE GEODETIC SURVEY                            
MEHD    MAINE HIGHWAY DEPARTMENT (NOW MEDT)              
MEPUC   MAINE PUBLIC UTILITIES COMMISSION                
MIDH    MICHIGAN DEPT OF STATE HIGHWAYS AND TRANSP       
MIDNR   MICHIGAN DEPARTMENT OF NATURAL RESOURCES         
MIDT    MICHIGAN DEPARTMENT OF TRANSPORTATION            
MIGS    MICHIGAN GEODETIC SURVEY                         
MNDNR   MINNESOTA DEPARTMENT OF NATURAL RESOURCES        
MNDT    MINNESOTA DEPARTMENT OF TRANSPORTATION           
MNGS    MINNESOTA GEODETIC SURVEY                        
MNHD    MINNESOTA HIGHWAY DEPARTMENT (NOW MNDT)          
MODNR   MISSOURI DEPARTMENT OF NATURAL RESOURCES         
MOGS    MISSOURI GEODETIC SURVEY                         
MOHC    MISSOURI STATE HIGHWAY COMMISSION                
MOSLSA  MISSOURI STATE LAND SURVEY AUTHORITY             
MSDEQ   MISSISSIPPI DEPARTMENT OF ENVIRONMENTAL QUALITY

                                 C-6
 STATE, PROVINCE, COMMONWEALTH, AND TERRITORIAL AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
MSGS    MISSISSIPPI GEODETIC SURVEY                      
MSHD    MISSISSIPPI STATE HIGHWAY DEPARTMENT             
MTBOR   MONTANA BUREAU OF PUBLIC ROADS                   
MTDH    MONTANA DEPARTMENT OF HIGHWAYS                  
MTDOT   MONTANA DEPARTMENT OF TRANSPORTATION            
MTGS    MONTANA GEODETIC SURVEY                          
MTSHC   MONTANA STATE HIGHWAY COMMISSION                 
NCDF    NORTH CAROLINA DIVISION OF FORESTRY              
NCDNR   NORTH CAROLINA DEPT OF NATURAL RESOURCES         
NCDOT   NORTH CAROLINA DEPT OF TRANS DIV OF HWYS         
NCGS    NORTH CAROLINA GEODETIC SURVEY                   
NCHC    NORTH CAROLINA HIGHWAY COMMISSION (NOW NCDOT)    
NCHPWC  NORTH CAROLINA HIGHWAY AND PUBLIC WORKS COMM     
NCSHC   NORTH CAROLINA STATE HIGHWAY COMMISSION          
NDGS    NORTH DAKOTA GEODETIC SURVEY                     
NDHD    NORTH DAKOTA HIGHWAY DEPARTMENT                  
NDWC    NORTH DAKOTA WATER COMMISSION                    
NEDR    NEBRASKA DEPARTMENT OF ROADS                     
NEGS    NEBRASKA GEODETIC SURVEY                         
NHDOT   NEW HAMPSHIRE DEPARTMENT OF TRANSPORTATION       
NHDPWH  NEW HAMPSHIRE DEPT OF PUBLIC WORKS + HWYS        
NHGS    NEW HAMPSHIRE GEODETIC SURVEY                    
NHHD    NEW HAMPSHIRE HIGHWAY DEPARTMENT                 
NJBCN   NEW JERSEY BOARD OF COMMERCE AND NAVIGATION      
NJDCED  NEW JERSEY DEPARTMENT OF CONSERVATION AND ECON DEV     
NJDEP   NEW JERSEY DEPARTMENT OF ENVIRONMENTAL PROTECTION
NJDT    NEW JERSEY DEPARTMENT OF TRANSPORTATION          
NJGS    NEW JERSEY GEODETIC SURVEY                       
NJHA    NEW JERSEY HIGHWAY AUTHORITY                     
NJSFC   NEW JERSEY SHELL FISHERIES COMMISSION            
NMGS    NEW MEXICO GEODETIC SURVEY                       
NMHC    NEW MEXICO STATE HIGHWAY COMMISSION              
NMHD    NEW MEXICO STATE HIGHWAY DEPARTMENT              
NVDH    NEVADA DEPARTMENT OF HIGHWAYS                    
NVDT    NEVADA DEPARTMENT OF TRANSPORTATION              
NVGS    NEVADA GEODETIC SURVEY                           
NYBE+A  NEW YORK BOARD OF ESTIMATE AND APPORTIONMENT     
NYDPW   NEW YORK STATE DEPARTMENT OF PUBLIC WORKS        
NYDT    NEW YORK STATE DEPARTMENT OF TRANSPORTATION      
NYGS    NEW YORK GEODETIC SURVEY                         
NYHD    NEW YORK DEPARTMENT OF HIGHWAYS (NOW NYDT)       
NYLISP  NEW YORK LONG ISLAND STATE PARK AUTHORITY        
NYNPA   NEW YORK NIAGARA POWER AUTHORITY                 
NYSE+S  NEW YORK STATE ENGINEER AND SURVEYOR             
NYSS    NEW YORK STATE SURVEY                            
OHDNR   OHIO DEPARTMENT OF NATURAL RESOURCES             
OHDT    OHIO DEPARTMENT OF TRANSPORTATION                
OHGS    OHIO GEODETIC SURVEY                             
OHHD    OHIO HIGHWAY DEPARTMENT (NOW OHDT)               
OKCC    OKLAHOMA CONSERVATION COMMISSION                 

                                 C-7
 STATE, PROVINCE, COMMONWEALTH, AND TERRITORIAL AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
OKDH    OKLAHOMA DEPARTMENT OF HIGHWAYS                  
OKDOT   OKLAHOMA DEPARTMENT OF TRANSPORTATION            
OKGS    OKLAHOMA GEODETIC SURVEY                         
ORDT    OREGON DEPARTMENT OF TRANSPORTATION              
ORGS    OREGON GEODETIC SURVEY                           
ORHD    OREGON STATE HIGHWAY DEPARTMENT (NOW ORDT)       
ORSLB   OREGON STATE LAND BOARD                          
ORTAX   OREGON STATE TAX COMMISSION                      
PADFW   PENNSYLVANIA DEPT OF FORESTS AND WATERS          
PADH    PENNSYLVANIA DEPT OF HIGHWAYS (NOW PADT)         
PADT    PENNSYLVANIA DEPARTMENT OF TRANSPORTATION        
PAGS    PENNSYLVANIA GEODETIC SURVEY                     
PRPWD   PUERTO RICO PUBLIC WORKS DEPARTMENT              
RIBPR   RHODE ISLAND BUREAU OF PUBLIC ROADS              
RIDT    RHODE ISLAND DEPARTMENT OF TRANSPORTATION        
RIGS    RHODE ISLAND GEODETIC SURVEY                     
SCCC    SOUTH CAROLINA COASTAL COUNCIL                   
SCDHPT  SOUTH CAROLINA DEPARTMENT OF HIGHWAYS AND PUBLIC
TRANSPORTATION
SCDOT   SOUTH CAROLINA DEPARTMENT OF TRANSPORTATION      
SCGS    SOUTH CAROLINA GEODETIC SURVEY                   
SCHD    SOUTH CAROLINA STATE HIGHWAY DEPARTMENT          
SCWRC   SOUTH CAROLINA WATER RESOURCE COMMISSION         
SDDT    SOUTH DAKOTA DEPARTMENT OF TRANSPORTATION        
SDGS    SOUTH DAKOTA GEODETIC SURVEY                     
SDHD    SOUTH DAKOTA HIGHWAY DEPARTMENT (NOW SDDT)       
TNDG    TENNESSEE DIVISION OF GEOLOGY                    
TNDPW   TENNESSEE DEPARTMENT OF PUBLIC WORKS             
TNDT    TENNESSEE DEPARTMENT OF TRANSPORTATION           
TNGS    TENNESSEE GEODETIC SURVEY                        
TNHD    TENNESSEE HIGHWAY DEPARTMENT (NOW TNDT)          
TXGS    TEXAS GEODETIC SURVEY                            
TXHD    TEXAS HIGHWAY DEPARTMENT                         
TXRD    TEXAS RECLAMATION DEPARTMENT                     
UTDH    UTAH STATE DEPARTMENT OF HIGHWAYS                
VACF    VIRGINIA COMMISSION OF FISHERIES                 
VADH    VIRGINIA DEPARTMENT OF HIGHWAYS                  
VADHT   VIRGINIA DEPT OF HIGHWAYS AND TRANSPORTATION     
VAGS    VIRGINIA GEODETIC SURVEY                         
VAMR    VIRGINIA MARINE RESOURCES
VTAT    VERMONT AGENCY OF TRANSPORTATION                 
VTDH    VERMONT DEPARTMENT OF HIGHWAYS (NOW VTAT)        
VTFS    VERMONT FOREST SERVICE                           
VTGS    VERMONT GEODETIC SURVEY                          
VTHP    VERMONT HISTORIC PRESERVATION
VTSM    STATE OF VERMONT SURVEY MARK 
WADNR   WASHINGTON DEPARTMENT OF NATURAL RESOURCES       
WADPL   WASHINGTON STATE DEPARTMENT OF PUBLIC LANDS      
WADPW   WASHINGTON DEPARTMENT OF PUBLIC WORKS            
WADT    WASHINGTON DEPARTMENT OF TRANSPORTATION          
WAGS    WASHINGTON GEODETIC SURVEY                       

                                 C-8
 STATE, PROVINCE, COMMONWEALTH, AND TERRITORIAL AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
WAHC    WASHINGTON STATE HIGHWAY COMMISSION              
WATBA   WASHINGTON STATE TOLL BRIDGE AUTHORITY           
WIDNR   WISCONSIN DEPARTMENT OF NATURAL RESOURCES        
WIDT    WISCONSIN DEPARTMENT OF TRANSPORTATION           
WIGS    WISCONSIN GEODETIC SURVEY                        
WIHD    WISCONSIN HIGHWAY DEPARTMENT (NOW WIDT)          
WIPSC   WISCONSIN PUBLIC SERVICE COMMISSION              
WIRRC   WISCONSIN RAILROAD COMMISSION                    
WVGS    WEST VIRGINIA GEODETIC SURVEY                    
WVHD    WEST VIRGINIA HIGHWAY DEPARTMENT                
WYDT    WYOMING DEPARTMENT OF TRANSPORTATION             
WYGS    WYOMING GEODETIC SURVEY                          
WYHD    WYOMING HIGHWAY DEPARTMENT  (NOW WYDT) 


                           COUNTY AGENCIES

SYMBOL      FULL NAME
****** 
***************************************************************
AK-020  BOROUGH OF ANCHORAGE ALASKA                      
AK-050  BETHEL CENSUS AREA
AK-160  LAKE AND PENINSULA BOROUGH
AK-185  NORTH SLOPE BOROUGH
AK-188  NORTHWEST ARCTIC BOROUGH
AK-290  YUKON-KOYUKUK CENSUS AREA
AL-107  PICKENS COUNTY ALABAMA                           
AL-119  SUMTER COUNTY ALABAMA                            
AZ-013  MARICOPA COUNTY ARIZONA                          
AZ-015  MOHAVE COUNTY ARIZONA                            
AZ-019  PIMA COUNTY ARIZONA                              
CA-001  ALAMEDA COUNTY CALIFORNIA                        
CA-007  BUTTE COUNTY CALIFORNIA                          
CA-013  CONTRA COSTA COUNTY CALIFORNIA                   
CA-019  FRESNO COUNTY CALIFORNIA                         
CA-023  HUMBOLDT COUNTY CALIFORNIA                       
CA-025  IMPERIAL COUNTY CALIFORNIA                       
CA-027  INYO COUNTY CALIFORNIA                           
CA-029  KERN COUNTY CALIFORNIA                           
CA-031  KINGS COUNTY CALIFORNIA                          
CA-033  LAKE COUNTY CALIFORNIA                           
CA-037  LOS ANGELES COUNTY CALIFORNIA                    
CA-041  MARIN COUNTY CALIFORNIA                          
CA-043  MARIPOSA COUNTY CALIFORNIA                       
CA-045  MENDOCINO COUNTY CALIFORNIA                      
CA-051  MONO COUNTY CALIFORNIA                           
CA-053  MONTEREY COUNTY CALIFORNIA                       
CA-055  NAPA COUNTY CALIFORNIA                           
CA-059  ORANGE COUNTY CALIFORNIA                         
CA-061  PLACER COUNTY CALIFORNIA                         
CA-063  PLUMAS COUNTY CALIFORNIA                         

                                 C-9
                     COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
CA-065  RIVERSIDE COUNTY CALIFORNIA                      
CA-067  SACRAMENTO COUNTY CALIFORNIA                     
CA-069  SAN BENITO COUNTY CALIFORNIA                     
CA-071  SAN BERNARDINO COUNTY CALIFORNIA                 
CA-073  SAN DIEGO COUNTY CALIFORNIA                      
CA-075  SAN FRANCISCO COUNTY CALIFORNIA                  
CA-077  SAN JOAQUIN COUNTY CALIFORNIA                    
CA-079  SAN LUIS OBISPO COUNTY CALIFORNIA                
CA-081  SAN MATEO COUNTY CALIFORNIA                      
CA-083  SANTA BARBARA COUNTY CALIFORNIA                 
CA-085  SANTA CLARA COUNTY CALIFORNIA                    
CA-087  SANTA CRUZ COUNTY CALIFORNIA                     
CA-089  SHASTA COUNTY CALIFORNIA                         
CA-091  SIERRA COUNTY CALIFORNIA                         
CA-093  SISKIYOU COUNTY CALIFORNIA                       
CA-097  SONOMA COUNTY CALIFORNIA                         
CA-099  STANISLAUS COUNTY CALIFORNIA                     
CA-103  TEHAMA COUNTY CALIFORNIA                         
CA-105  TRINITY COUNTY CALIFORNIA                        
CA-107  TULARE COUNTY CALIFORNIA                         
CA-109  TUOLUMNE COUNTY CALIFORNIA                       
CA-111  VENTURA COUNTY CALIFORNIA                        
CA-113  YOLO COUNTY CALIFORNIA                           
CO-001  ADAMS COUNTY COLORADO                            
CO-005  ARAPAHOE COUNTY COLORADO                         
CO-013  BOULDER COUNTY COLORADO                          
CO-017  CHEYENNE COUNTY COLORADO                         
CO-059  JEFFERSON COUNTY COLORADO                        
CO-061  KIOWA COUNTY COLORADO                            
CO-069  LARIMER COUNTY COLORADO                          
CO-077  MESA COUNTY COLORADO                             
CO-123  WELD COUNTY COLORADO                             
FL-001  ALACHUA COUNTY FLORIDA                           
FL-011  BROWARD COUNTY FLORIDA                           
FL-015  CHARLOTTE COUNTY FLORIDA                         
FL-017  CITRUS COUNTY FLORIDA                            
FL-025  DADE COUNTY FLORIDA                              
FL-053  HERNANDO COUNTY FLORIDA                          
FL-057  HILLSBOROUGH COUNTY FLORIDA                      
FL-071  LEE COUNTY FLORIDA                               
FL-081  MANATEE COUNTY FLORIDA                           
FL-083  MARION COUNTY FLORIDA                            
FL-085  MARTIN COUNTY FLORIDA
FL-091  OKALOOSA COUNTY FLORIDA                          
FL-095  ORANGE COUNTY FLORIDA                            
FL-099  PALM BEACH COUNTY FLORIDA                        
FL-101  PASCO COUNTY FLORIDA                             
FL-103  PINELLAS COUNTY FLORIDA                          
FL-115  SARASOTA COUNTY FLORIDA                          
FL-131  WALTON COUNTY FLORIDA                            

                                C-10
                     COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
GA-067  COBB COUNTY GEORGIA                              
GA-089  DE KALB COUNTY GEORGIA                           
GA-095  DOUGHERTY COUNTY GEORGIA                         
GA-121  FULTON COUNTY GEORGIA                            
GA-135  GWINNETT COUNTY GEORGIA                          
IA-033  CERRO GORDO COUNTY IOWA                          
IA-035  CHEROKEE COUNTY IOWA                             
IA-037  CHICKASAW COUNTY IOWA                            
IA-057  DES MOINES COUNTY IOWA                           
IA-059  DICKINSON COUNTY IOWA                            
IA-063  EMMET COUNTY IOWA                               
IA-065  FAYETTE COUNTY IOWA                              
IA-077  GUTHRIE COUNTY IOWA                              
IA-083  HARDIN COUNTY IOWA                               
IA-105  JONES COUNTY IOWA                                
IA-113  LINN COUNTY IOWA                                 
IA-125  MARION COUNTY IOWA                               
IA-147  PALO ALTO COUNTY IOWA                            
IA-159  RINGGOLD COUNTY IOWA                             
IA-165  SHELBY COUNTY IOWA                               
IA-167  SIOUX COUNTY IOWA                                
IA-169  STORY COUNTY IOWA                                
IA-199  LYON COUNTY IOWA                                 
ID-011  ADA COUNTY IDAHO                                 
ID-079  SHOSHONE COUNTY IDAHO                            
IL-031  COOK COUNTY ILLINOIS                             
IL-043  DU PAGE COUNTY ILLINOIS                          
IL-051  FAYETTE COUNTY ILLINOIS
IL-103  LEE COUNTY ILLINOIS                              
IL-125  MADISON COUNTY ILLINOIS                          
IL-163  ST CLAIR COUNTY ILLINOIS                         
IL-195  WHITESIDE COUNTY ILLINOIS                        
IN-003  ALLEN COUNTY INDIANA                             
IN-039  ELKHART COUNTY INDIANA                           
IN-085  KOSCIUSKO COUNTY INDIANA                         
IN-127  PORTER COUNTY INDIANA                            
IN-131  PULASKI COUNTY INDIANA                           
IN-141  ST JOSEPH COUNTY INDIANA                         
KS-007  BARBER COUNTY KANSAS                             
KS-009  BARTON COUNTY KANSAS                             
KS-167  RUSSELL COUNTY KANSAS                            
KS-189  STEVENS COUNTY KANSAS                            
KS-203  WICHITA COUNTY KANSAS                            
KS-207  WOODSON COUNTY KANSAS                            
KS-209  WYANDOTTE COUNTY KANSAS                          
LA-019  CALASIEU PARISH LOUISIANA                        
LA-033  EAST BATON ROUGE PARISH LOUISIANA                
LA-051  JEFFERSON PARISH LOUISIANA                       
LA-087  ST BERNARD PARISH LOUISIANA                      
LA-101  ST MARY PARISH LOUISIANA                         

                                C-11
                     COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
MD-003  ANNE ARUNDEL COUNTY MARYLAND                     
MD-017  CHARLES COUNTY MARYLAND                          
MD-019  DORCHESTER COUNTY MARYLAND                       
MD-021  FREDERICK COUNTY MARYLAND                        
MD-025  HARFORD COUNTY MARYLAND                          
MD-027  HOWARD COUNTY MARYLAND                           
MD-043  WASHINGTON COUNTY MARYLAND                       
ME-007  FRANKLIN COUNTY MAINE                            
MI-005  ALLEGAN COUNTY MICHIGAN                          
MI-011  ARENAC COUNTY MICHIGAN                           
MI-033  CHIPPEWA COUNTY MICHIGAN                         
MI-053  GOGEBIC COUNTY MICHIGAN                          
MI-061  HOUGHTON COUNTY MICHIGAN                        
MI-063  HURON COUNTY MICHIGAN                            
MI-075  JACKSON COUNTY MICHIGAN                          
MI-081  KENT COUNTY MICHIGAN                             
MI-125  OAKLAND COUNTY MICHIGAN                          
MI-163  WAYNE COUNTY MICHIGAN                            
MN-019  CARVER COUNTY MINNESOTA                          
MN-037  DAKOTA COUNTY MINNESOTA                          
MN-049  GOODHUE COUNTY MINNESOTA                         
MN-061  ITASCA COUNTY MINNESOTA                          
MN-075  LAKE COUNTY MINNESOTA                            
MN-103  NICOLLET COUNTY MINNESOTA                        
MN-109  OLMSTED COUNTY MINNESOTA                         
MN-137  ST LOUIS COUNTY MINNESOTA                        
MN-153  TODD COUNTY MINNESOTA                            
MN-161  WASECA COUNTY MINNESOTA                          
MN-163  WASHINGTON COUNTY MINNESOTA                      
MN-165  WATONWAN COUNTY MINNESOTA                        
MS-059  JACKSON COUNTY MISSISSIPPI                       
MS-135  TALLAHATCHIE COUNTY MISSISSIPPI                  
MS-145  UNION COUNTY MISSISSIPPI                         
NC-045  CLEVELAND COUNTY NORTH CAROLINA                  
NC-095  HYDE COUNTY NORTH CAROLINA                       
NC-129  NEW HANOVER COUNTY NORTH CAROLINA                
NC-183  WAKE COUNTY NORTH CAROLINA                       
ND-057  MERCER COUNTY NORTH DAKOTA                       
NE-141  PLATTE COUNTY NEBRASKA                           
NE-167  STANTON COUNTY NEBRASKA                          
NJ-017  HUDSON COUNTY NEW JERSEY                         
NJ-035  SOMERSET COUNTY NEW JERSEY                       
NM-049  SANTA FE COUNTY NEW MEXICO
NV-027  PERSHING COUNTY NEVADA                           
NV-031  WASHOE COUNTY NEVADA                             
NY-005  BOROUGH OF BRONX NEW YORK                        
NY-023  CORTLAND COUNTY NEW YORK                         
NY-025  DELAWARE COUNTY NEW YORK                         
NY-029  ERIE COUNTY NEW YORK                             


                                C-12
                     COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
NY-035  FULTON COUNTY NEW YORK                           
NY-055  MONROE COUNTY NEW YORK                           
NY-057  MONTGOMERY COUNTY NEW YORK                       
NY-059  NASSAU COUNTY NEW YORK                           
NY-065  ONEIDA COUNTY NEW YORK                           
NY-069  ONTARIO COUNTY NEW YORK                          
NY-085  BOROUGH OF RICHMOND NEW YORK                     
NY-091  SARATOGA COUNTY NEW YORK                         
NY-103  SUFFOLK COUNTY NEW YORK                          
NY-111  ULSTER COUNTY NEW YORK                           
NY-119  WESTCHESTER COUNTY NEW YORK                      
OH-013  BELMONT COUNTY OHIO                              
OH-017  BUTLER COUNTY OHIO                               
OH-023  CLARK COUNTY OHIO
OH-031  COSHOCTON COUNTY OHIO                            
OH-035  CUYAHOGA COUNTY OHIO                            
OH-041  DELAWARE COUNTY OHIO                             
OH-047  FAYETTE COUNTY OHIO                              
OH-049  FRANKLIN COUNTY OHIO                             
OH-051  FULTON COUNTY OHIO                               
OH-055  GEAUGA COUNTY OHIO                               
OH-057  GREENE COUNTY OHIO                              
OH-095  LUCAS COUNTY OHIO                                
OH-099  MAHONING COUNTY OHIO                             
OH-109  MIAMI COUNTY OHIO
OH-113  MONTGOMERY COUNTY OHIO                           
OH-119  MUSKINGUM COUNTY OHIO                            
OH-133  PORTAGE COUNTY OHIO                              
OH-151  STARK COUNTY OHIO                                
OH-153  SUMMIT COUNTY OHIO                               
OK-003  ALFALFA COUNTY OKLAHOMA                          
OK-133  SEMINOLE COUNTY OKLAHOMA                         
OR-011  COOS COUNTY OREGON                               
OR-015  CURRY COUNTY OREGON                              
OR-017  DESCHUTES COUNTY OREGON                          
OR-019  DOUGLAS COUNTY OREGON                            
OR-029  JACKSON COUNTY OREGON                            
OR-033  JOSEPHINE COUNTY OREGON                          
OR-035  KLAMATH COUNTY OREGON                           
OR-039  LANE COUNTY OREGON                               
OR-043  LINN COUNTY OREGON                               
OR-047  MARION COUNTY OREGON                             
OR-049  MORROW COUNTY OREGON                            
OR-051  MULTNOMAH COUNTY OREGON                          
OR-053  POLK COUNTY OREGON                               
OR-067  WASHINGTON COUNTY OREGON                         
OR-071  YAMHILL COUNTY OREGON                            
PA-003  ALLEGHENY COUNTY PENNSYLVANIA                    
PA-029  CHESTER COUNTY PENNSYLVANIA                      
PA-085  MERCER COUNTY PENNSYLVANIA                       

                                C-13
                     COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
PA-091  MONTGOMERY COUNTY PENNSYLVANIA                   
PA-133  YORK COUNTY PENNSYLVANIA      
SC-003  AIKEN COUNTY SOUTH CAROLINA                    
SC-013  BEAUFORT COUNTY SOUTH CAROLINA                   
SC-083  SPARTANBURG COUNTY SOUTH CAROLINA                
TN-003  BEDFORD COUNTY TENNESSEE                         
TN-069  HARDEMAN COUNTY TENNESSEE                        
TX-039  BRAZORIA COUNTY TEXAS                            
TX-049  BROWN COUNTY TEXAS                               
TX-057  CALHOUN COUNTY TEXAS                             
TX-141  EL PASO COUNTY TEXAS                             
TX-165  GAINES COUNTY TEXAS                              
TX-177  GONZALES COUNTY TEXAS                            
TX-195  HANSFORD COUNTY TEXAS                            
TX-281  LAMPASAS COUNTY TEXAS                            
TX-321  MATAGORDA COUNTY TEXAS                           
TX-355  NUECES COUNTY TEXAS                              
UT-035  SALT LAKE COUNTY UTAH                            
UT-049  UTAH COUNTY UTAH                                 
VA-009  AMHERST COUNTY VIRGINIA                          
VA-019  BEDFORD COUNTY VIRGINIA                         
VA-031  CAMPBELL COUNTY VIRGINIA                        
VA-059  FAIRFAX COUNTY VIRGINIA                          
VA-061  FAUQUIER COUNTY VIRGINIA                        
VA-085  HANOVER COUNTY VIRGINIA                          
VA-087  HENRICO COUNTY VIRGINIA                          
VA-095  JAMES CITY COUNTY VIRGINIA                       
VA-153  PRINCE WILLIAM COUNTY VIRGINIA                  
VA-199  YORK COUNTY VIRGINIA                             
WA-001  ADAMS COUNTY WASHINGTON
WA-005  BENTON COUNTY WASHINGTON                        
WA-009  CLALLAM COUNTY WASHINGTON                        
WA-011  CLARK COUNTY WASHINGTON                          
WA-015  COWLITZ COUNTY WASHINGTON                        
WA-017  DOUGLAS COUNTY WASHINGTON
WA-021  FRANKLIN COUNTY WASHINGTON                       
WA-025  GRANT COUNTY WASHINGTON                         
WA-029  ISLAND COUNTY WASHINGTON                         
WA-033  KING COUNTY WASHINGTON                           
WA-039  KLICKITAT COUNTY WASHINGTON                      
WA-041  LEWIS COUNTY WASHINGTON                         
WA-047  OKANOGAN COUNTY WASHINGTON                      
WA-049  PACIFIC COUNTY WASHINGTON                        
WA-053  PIERCE COUNTY WASHINGTON                        
WA-057  SKAGIT COUNTY WASHINGTON                        
WA-061  SNOHOMISH COUNTY WASHINGTON
WA-065  STEVENS COUNTY WASHINGTON                       
WA-077  YAKIMA COUNTY WASHINGTON                         
WI-025  DANE COUNTY WISCONSIN                            
WI-027  DODGE COUNTY WISCONSIN                           

                                C-14
                     COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
WI-031  DOUGLAS COUNTY WISCONSIN                         
WI-035  DUNN COUNTY WISCONSIN                            
WI-039  FOND DU LAC COUNTY WISCONSIN                     
WI-101  RACINE COUNTY WISCONSIN                          
WV-069  OHIO COUNTY WEST VIRGINIA                        
WV-085  RITCHIE COUNTY WEST VIRGINIA                    


                     MUNICIPAL AGENCIES (CITIES)

SYMBOL      FULL NAME
******      ********************************************************
            *******
AK0130  CITY OF ANCHORAGE ALASKA                         
AK1250  CITY OF KETCHIKAN ALASKA                         
AL0930  CITY OF DOTHAN ALABAMA                           
AL1510  CITY OF HUNTSVILLE ALABAMA                       
AL2130  CITY OF MONTGOMERY ALABAMA                       
AR3390  CITY OF ROGERS ARKANSAS                          
AR3880  CITY OF TUPELO ARKANSAS                          
AR4063  CITY OF WELDON ARKANSAS                          
AZ0370  CITY OF PHOENIX ARIZONA                          
AZ0420  CITY OF SCOTTSDALE ARIZONA                       
AZ0490  CITY OF TEMPE ARIZONA                            
CA0010  CITY OF ALAMEDA CALIFORNIA                       
CA0340  CITY OF BERKELEY CALIFORNIA                      
CA0470  CITY OF BUENA PARK CALIFORNIA                    
CA0480  CITY OF BURBANK CALIFORNIA                       
CA0537  CITY OF CAMPBELL CALIFORNIA                      
CA0710  CITY OF CHULA VISTA CALIFORNIA                   
CA0790  CITY OF COLTON CALIFORNIA                        
CA1182  CITY OF ENCINITAS CALIFORNIA                     
CA1220  CITY OF EUREKA CALIFORNIA                        
CA1364  CITY OF FREMONT CALIFORNIA                       
CA1370  CITY OF FRESNO CALIFORNIA                        
CA1430  CITY OF GLENDALE CALIFORNIA                      
CA1450  CITY OF GONZALES CALIFORNIA                      
CA1520  CITY OF GUSTINE CALIFORNIA                       
CA1540  CITY OF HANFORD CALIFORNIA                       
CA1560  CITY OF HAYWARD CALIFORNIA                       
CA1580  CITY OF HEMET CALIFORNIA                         
CA1660  CITY OF HUNTINGTON BEACH CALIFORNIA              
CA1970  CITY OF LONG BEACH CALIFORNIA                    
CA1980  CITY OF LOS ANGELES CALIFORNIA                   
CA2090  CITY OF MARTINEZ CALIFORNIA                      
CA2280  CITY OF MORGAN HILL CALIFORNIA                   
CA2290  CITY OF MORROW BAY CALIFORNIA                    
CA2330  CITY OF NAPA CALIFORNIA                          
CA2390  CITY OF NEWMAN CALIFORNIA                        
CA2460  CITY OF NOVATO CALIFORNIA                        
CA2480  CITY OF OAKLAND CALIFORNIA                       

                                C-15
               MUNICIPAL AGENCIES (CITIES) - CONTINUED

SYMBOL      FULL NAME
******      ********************************************************
            *******
CA2550  CITY OF ONTARIO CALIFORNIA                       
CA2650  CITY OF PALM SPRINGS CALIFORNIA                  
CA2700  CITY OF PASADENA CALIFORNIA                      
CA2780  CITY OF PISMO BEACH CALIFORNIA                   
CA2840  CITY OF PLEASANTON CALIFORNIA                    
CA2880  CITY OF PORTERVILLE CALIFORNIA                   
CA2940  CITY OF RED BLUFF CALIFORNIA                     
CA2970  CITY OF REDONDO BEACH CALIFORNIA                 
CA2980  CITY OF REDWOOD CITY CALIFORNIA                  
CA3070  CITY OF RIVERSIDE CALIFORNIA                     
CA3210  CITY OF SAN BERNARDINO CALIFORNIA                
CA3260  CITY OF SAN DIEGO CALIFORNIA                     
CA3280  CITY OF SAN FERNANDO CALIFORNIA                  
CA3290  CITY OF SAN FRANCISCO CALIFORNIA                 
CA3340  CITY OF SAN JOSE CALIFORNIA                      
CA3370  CITY OF SAN LUIS OBISPO CALIFORNIA               
CA3380  CITY OF SAN MARINO CALIFORNIA                    
CA3390  CITY OF SAN MATEO CALIFORNIA                     
CA3410  CITY OF SAN RAFAEL CALIFORNIA                    
CA3420  CITY OF SANTA ANA CALIFORNIA                     
CA3440  CITY OF SANTA CLARA CALIFORNIA                   
CA3460  CITY OF SANTA MARIA CALIFORNIA                   
CA3480  CITY OF SANTA PAULA CALIFORNIA                   
CA3490  CITY OF SANTA ROSA CALIFORNIA                    
CA3590  CITY OF SELMA CALIFORNIA                         
CA3660  CITY OF SONOMA CALIFORNIA                        
CA3800  CITY OF SUSANVILLE CALIFORNIA                    
CA3920  CITY OF TULARE CALIFORNIA                        
CA4020  CITY OF VALLEJO CALIFORNIA                       
CA4027  CITY OF VENTURA CALIFORNIA                       
CA4070  CITY OF WALNUT CREEK CALIFORNIA                  
CA4100  CITY OF WATSONVILLE CALIFORNIA                   
CO0600  CITY AND COUNTY OF DENVER                        
CO2150  CITY OF ROCKY FORD COLORADO                      
CT0080  CITY OF BRIDGEPORT CONNECTICUT                   
CT0237  CITY OF FARMINGTON CONNECTICUT                   
CT0280  CITY OF HARTFORD CONNECTICUT                     
CT0360  CITY OF MADISON CONNECTICUT                      
CT0370  CITY OF MERIDEN CONNECTICUT                      
CT0380  CITY OF MIDDLETOWN CONNECTICUT                   
CT0430  CITY OF NEW HAVEN CONNECTICUT                    
CT0810  CITY OF WATERBURY CONNECTICUT                    
DC001   CITY OF WASHINGTON DC                            
FL0290  CITY OF BOCA RATON FLORIDA                       
FL0570  CITY OF CLEARWATER FLORIDA                       
FL0780  CITY OF DAYTONA BEACH FLORIDA                    
FL1420  CITY OF HOLLYWOOD FLORIDA                        
FL1510  CITY OF JACKSONVILLE FLORIDA                     
FL1590  CITY OF KISSIMMEE FLORIDA                        
FL1690  CITY OF LAKELAND FLORIDA                         

                                C-16
               MUNICIPAL AGENCIES (CITIES) - CONTINUED

SYMBOL      FULL NAME
******      ********************************************************
            *******
FL2010  CITY OF MIAMI FLORIDA                            
FL2360  CITY OF ORLANDO FLORIDA                         
FL2730  CITY OF ST PETERSBURG FLORIDA                    
FL2940  CITY OF TALLAHASSEE FLORIDA                      
GA0280  CITY OF ATLANTA GEORGIA                          
GA0760  CITY OF BRUNSWICK GEORGIA                        
GA1780  CITY OF DUBLIN GEORGIA                           
GA3440  CITY OF MARIETTA GEORGIA                         
GA4910  CITY OF SAVANNAH GEORGIA                         
HI2400  CITY OF HONOLULU HAWAII                          
IA2520  CITY OF DYSART IOWA                              
IA2530  CITY OF EAGLE GROVE IOWA                         
IA5240  CITY OF MAQUOKETA IOWA                           
IA7490  CITY OF SAC CITY IOWA                            
IA8880  CITY OF WEBSTER CITY IOWA                        
ID0790  CITY OF IDAHO FALLS IDAHO                        
ID1830  CITY OF TWIN FALLS IDAHO                         
IL0512  CITY OF BARRINGTON HILLS ILLINOIS               
IL0840  CITY OF BLOOMINGTON ILLINOIS                     
IL1550  CITY OF CHAMPAIGN ILLINOIS                       
IL1670  CITY OF CHICAGO ILLINOIS                         
IL2380  CITY OF DIXON ILLINOIS                           
IL3200  CITY OF FREEBURG ILLINOIS                        
IL3910  CITY OF HIGHLAND PARK ILLINOIS                   
IL4710  CITY OF LAWRENCEVILLE ILLINOIS                   
IL4910  CITY OF LOCKPORT ILLINOIS                        
IL5360  CITY OF MASON CITY ILLINOIS                      
IL6850  CITY OF PEORIA ILLINOIS                          
IL7460  CITY OF ROCKFORD ILLINOIS                        
IL7640  CITY OF ST CHARLES ILLINOIS                      
IL9210  CITY OF WESTERN SPRINGS ILLINOIS                 
IL9450  CITY OF WINNEBAGO ILLINOIS                       
IN1830  CITY OF GOSHEN INDIANA                           
IN3480  CITY OF NEW HAVEN INDIANA                        
KS5400  CITY OF TOPEKA KANSAS                            
KY2090  CITY OF LOUISVILLE KENTUCKY                      
LA0040  CITY OF ALEXANDRIA LOUISIANA                     
LA1150  CITY OF JONESBORO LOUISIANA                      
LA1690  CITY OF NEW ORLEANS LOUISIANA                    
LA2410  CITY OF WEST MONROE LOUISIANA                    
MA0035  CITY OF ANDOVER MASSACHUSETTS                    
MA0120  CITY OF BOSTON MASSACHUSETTS                     
MA0170  CITY OF CAMBRIDGE MASSACHUSETTS                  
MA0660  CITY OF MALDEN MASSACHUSETTS                     
MA1520  CITY OF WORCESTER MASSACHUSETTS
MD0050  CITY OF BALTIMORE MARYLAND                       
MD0580  CITY OF FREDERICK MARYLAND                       
MD0730  CITY OF HAGERSTOWN MARYLAND                      
MD1380  CITY OF SALISBURY                                
ME0250  CITY OF BANGOR MAINE                             

                                C-17
               MUNICIPAL AGENCIES (CITIES) - CONTINUED

SYMBOL      FULL NAME
******      ********************************************************
            *******
ME6400  CITY OF PORTLAND MAINE                           
MI0310  CITY OF BATTLE CREEK MICHIGAN                    
MI0490  CITY OF BIRMINGHAM MICHIGAN                      
MI0700  CITY OF CADILLAC MICHIGAN                        
MI0890  CITY OF CHARLOTTE MICHIGAN                       
MI1150  CITY OF CROSWELL MICHIGAN                        
MI1260  CITY OF DETROIT MICHIGAN                         
MI1730  CITY OF FLINT MICHIGAN                           
MI1800  CITY OF FRANKFORT MICHIGAN                       
MI2010  CITY OF GRAND RAPIDS MICHIGAN                    
MI2520  CITY OF KALAMAZOO MICHIGAN                       
MI2990  CITY OF MANTON MICHIGAN                          
MI3320  CITY OF MONROE MICHIGAN                          
MI3740  CITY OF OTSEGO MICHIGAN                          
MI4020  CITY OF PONTIAC MICHIGAN                         
MI4760  CITY OF STURGIS MICHIGAN                         
MI5310  CITY OF WYANDOTTE MICHIGAN                       
MN1150  CITY OF CHAMPLIN MINNESOTA                       
MN1210  CITY OF CHISHOLM MINNESOTA                       
MN2860  CITY OF GRANITE FALLS MINNESOTA                  
MN3460  CITY OF HUTCHINSON MINNESOTA                     
MN4760  CITY OF MINNEAPOLIS MINNESOTA                    
MN5660  CITY OF PINE CITY MINNESOTA                      
MO4100  CITY OF JOPLIN MISSOURI                          
MO7070  CITY OF ST JOSEPH MISSOURI                       
MO7080  CITY OF ST LOUIS MISSOURI                        
NC0870  CITY OF CHARLOTTE NORTH CAROLINA                 
NC1460  CITY OF ELIZABETH CITY NORTH CAROLINA            
NC1940  CITY OF GREENSBORO NORTH CAROLINA                
NC2450  CITY OF KINSTON NORTH CAROLINA                   
NC3100  CITY OF MONROE NORTH CAROLINA                    
NC4070  CITY OF SALISBURY NORTH CAROLINA                 
NH0020  CITY OF BERLIN NEW HAMPSHIRE                     
NH0070  CITY OF CONCORD NEW HAMPSHIRE                    
NH0310  CITY OF MANCHESTER NEW HAMPSHIRE                 
NH0430  CITY OF PORTSMOUTH NEW HAMPSHIRE                 
NJ0520  CITY OF CAMDEN NEW JERSEY                        
NJ1775  CITY OF LYNDHURST NEW JERSEY                     
NJ2130  CITY OF NEWARK NEW JERSEY                       
NJ2498  CITY OF PARSIPPANY NEW JERSEY                   
NJ2510  CITY OF PATERSON NEW JERSEY                      
NJ2570  CITY OF PERTH AMBOY NEW JERSEY                   
NJ3380  CITY OF TRENTON NEW JERSEY                       
NJ3705  CITY OF WOODBRIDGE NEW JERSEY                    
NM0030  CITY OF ALBUQUERQUE NEW MEXICO                   
NM0170  CITY OF CLAYTON NEW MEXICO                       
NM0470  CITY OF LAS CRUCES NEW MEXICO                    
NM0710  CITY OF SANTA FE NEW MEXICO
NV0139  CITY OF MOUNTAIN CITY NEVADA                     
NV0170  CITY OF RENO NEVADA                              

                                C-18
               MUNICIPAL AGENCIES (CITIES) - CONTINUED

SYMBOL      FULL NAME
******      ********************************************************
            *******
NY0750  CITY OF BUFFALO NEW YORK                         
NY3070  CITY OF LACKAWANNA NEW YORK                      
NY3340  CITY OF LOCKPORT NEW YORK                        
NY3940  CITY OF MOUNT VERNON NEW YORK                    
NY4120  CITY OF NEW ROCHELLE NEW YORK                    
NY4170  CITY OF NEW YORK NEW YORK                        
NY4210  CITY OF NIAGARA FALLS NEW YORK                   
NY5230  CITY OF ROCHESTER NEW YORK                       
NY5550  CITY OF SCHENECTADY NEW YORK                     
NY6450  CITY OF WATERTOWN NEW YORK                       
NY6820  CITY OF YONKERS NEW YORK                         
OH0070  CITY OF AKRON OHIO                               
OH1320  CITY OF CANTON OHIO                              
OH1610  CITY OF CINCINNATI OHIO                          
OH1680  CITY OF CLEVELAND OHIO                           
OH1800  CITY OF COLUMBUS OHIO                            
OH2090  CITY OF DAYTON OHIO                              
OH3895  CITY OF KETTERING OHIO                           
OH4730  CITY OF MARIETTA OHIO                            
OH4820  CITY OF MASSILLON OHIO                           
OH8070  CITY OF TIFFIN OHIO                              
OH8120  CITY OF TOLEDO OHIO                              
OR1225  CITY OF LINCOLN CITY OREGON                      
OR1260  CITY OF MCMINNVILLE OREGON                       
OR1310  CITY OF MEDFORD OREGON                           
OR1500  CITY OF NEWPORT OREGON                           
OR1510  CITY OF NORTH BEND OREGON                        
OR1650  CITY OF PORTLAND OREGON                          
OR1810  CITY OF SALEM OREGON                             
PA0110  CITY OF ALLENTOWN PENNSYLVANIA                   
PA1230  CITY OF CHAMBERSBURG PENNSYLVANIA                
PA1296  CITY OF CHESTER TOWNSHIP PENNSYLVANIA            
PA1335  CITY OF CLAIRTON PENNSYLVANIA
PA2270  CITY OF EASTON PENNSYLVANIA                      
PA4010  CITY OF JOHNSTOWN PENNSYLVANIA                   
PA6540  CITY OF PHILADELPHIA PENNSYLVANIA
PA6600  CITY OF PITTSBURGH PENNSYLVANIA                  
PA8880  CITY OF WASHINGTON PENNSYLVANIA                  
PA8920  CITY OF WAYNESBORO PENNSYLVANIA                  
SC0020  CITY OF AIKEN SOUTH CAROLINA
SC0370  CITY OF CAYCE SOUTH CAROLINA                     
SD2730  CITY OF VERMILLION SOUTH DAKOTA                  
SD3070  CITY OF YANKTON SOUTH DAKOTA
TX0530  CITY OF BELLAIRE TEXAS                           
TX1550  CITY OF CORPUS CHRISTI TEXAS                     
TX1730  CITY OF DALLAS TEXAS                             
TX2190  CITY OF EL PASO TEXAS                            
TX2450  CITY OF FORT WORTH TEXAS                         
TX3280  CITY OF HOUSTON TEXAS                            
TX5430  CITY OF PORT ARTHUR TEXAS                        

                                C-19
               MUNICIPAL AGENCIES (CITIES) - CONTINUED

SYMBOL      FULL NAME
******      ********************************************************
            *******
TX6090  CITY OF SAN ANTONIO TEXAS                        
UT1560  CITY OF PROVO UTAH                              
VA0130  CITY OF BEDFORD VIRGINIA                        
VA0690  CITY OF CULPEPER VIRGINIA                        
VA0720  CITY OF DANVILLE VIRGINIA                        
VA1180  CITY OF HAMPTON VIRGINIA                        
VA1490  CITY OF LYNCHBURG VIRGINIA                      
VA1720  CITY OF NEWPORT NEWS VIRGINIA                    
VA1760  CITY OF NORFOLK VIRGINIA                         
VA2060  CITY OF RICHMOND VIRGINIA                        
VA2330  CITY OF STAUNTON VIRGINIA                        
VA2540  CITY OF VIRGINIA BEACH VIRGINIA                  
VA2570  CITY OF WARRENTON VIRGINIA                      
WA0109  CITY OF BELLEVUE WASHINGTON
WA0180  CITY OF BREMERTON WASHINGTON
WA1190  CITY OF LONGVIEW WASHINGTON
WA1550  CITY OF OAK HARBOR WASHINGTON
WA1820  CITY OF REDMOND WASHINGTON
WA1850  CITY OF RICHLAND WASHINGTON
WA1960  CITY OF SEATTLE WASHINGTON
WA2110  CITY OF SPOKANE WASHINGTON
WA2230  CITY OF TAKOMA WASHINGTON
WI1470  CITY OF EAU CLAIRE WISCONSIN
WI1760  CITY OF FORT ATKINSON WISCONSIN
WI2320  CITY OF JANESVILLE WISCONSIN
WI3100  CITY OF MILWAUKEE WISCONSIN
WI3810  CITY OF PLYMOUTH WISCONSIN
WI3970  CITY OF RACINE WICONSIN
WI4060  CITY OF RHINELANDER WISCONSIN
WI4330  CITY OF SHEBOYGAN WISCONSIN
WI4730  CITY OF SUPERIOR WISCONSIN
WV0260  CITY OF BLUEFIELD WEST VIRGINIA


                INTER-CITY AND INTER-COUNTY AGENCIES

SYMBOL  FULL NAME
******      ********************************************************
            *******
ACSWM   ADDISON COUNTY SOLID WASTE MANAGEMENT DEPARTMENT
ACWD    ALAMEDA COUNTY WATER DISTRICT                    
AEWD    ARVIN-EDISON WATER DISTRICT                      
BART    BAY AREA RAPID TRANSIT                           
BCE     BROWARD COUNTY ENGINEERS                         
BRICKT  BRICK TOWNSHIP
CCPUD   CHELAN COUNTY PUBLIC UTILITIES DISTRICT
CID     CENTERVILLE IRRIGATION DISTRICT                  
CRGS    CLEVELAND REGIONAL GEODETIC SURVEY               
DCE     DELAWARE COUNTY ENGINEER                         
DCENG   DOUGLAS COUNTY ENGINEER
DCPW    DOUGLAS COUNTY PUBLIC WORKS

                                C-20
          INTER-CITY AND INTER-COUNTY AGENCIES - CONTINUED

SYMBOL  FULL NAME
******      ********************************************************
            *******
DEGS    DELAWARE GEOLOGICAL SURVEY                       
DMWW    DENVER MUNICIPAL WATER WORKS                     
EBDA    EAST BAY SEWAGE DISCHARGE AUTHORITY              
EBMUD   EAST BAY MUNICIPAL UTILITIES DISTRICT            
FCA     FAIRFIELD COUNTY AUDITOR                        
GCENG   GREENE COUNTY ENGINEER
GCPUD   GRANT COUNTY PUBLIC UTILITIES DISTRICT
HAMTWP  HAMILTON TOWNSHIP
HCFC    HARRIS COUNTY TEXAS FLOOD CONTROL DISTRICT       
HHWS    HETCH HETCHY WATER SUPPLY DISTRICT               
IAA     INDIANAPOLIS AIRPORT AUTHORITY                   
IID     IMPERIAL IRRIGATION DISTRICT                     
IMAGIS  INDIANAPOLIS MAPPING AND GEOGRAPHIC INFRA SYSTEM
JCAD    JEFFERSON COUNTY APPRAISAL DISTRICT              
JCMD    JEFFERSON COUNTY MAPPING DEPARTMENT              
LACFCD  LOS ANGELES FLOOD CONTROL DISTRICT               
LAHRBR  LOS ANGELES HARBOR DEPARTMENT                    
LAWPC   LOS ANGELES WATER AND POWER COMMISSION           
LFUCG   LEXINGTON FAYETTE URBAN COUNTY GOVERNMENT        
LVDPW   LAS VEGAS DEPARTMENT OF PUBLIC WORKS             
MARTA   METROPOLITAN ATLANTA RAPID TRANSIT AUTHORITY     
MID     MODESTO IRRIGATION DISTRICT                      
MRGCD   MIDDLE RIO GRANDE CONSERVATION DISTRICT          
MRMSC   MILWAUKEE-RACINE METROPOLITAN SEWAGE COMM        
MWAA    METROPOLITAN WASHINGTON AIRPORT AUTHORITY       
MWDSC   METROPOLITAN WATER DISTRICT OF SO CALIFORNIA     
NNWW    NEWPORT NEWS WATER WORKS                         
NOS+WB  NEW ORLEANS SEWERAGE AND WATER BOARD             
NYPA    NEW YORK PORT AUTHORITY                          
OID     OAKDALE IRRIGATION DISTRICT                      
OROW    OHIO RIVER ORDINANCE WORKS                       
PIMACO  PIMA CO DEPT OF TRANSP AND FLOOD CONTROL DIST    
PTHT    PARSIPPANY TROY HILLS TOWNSHIP
RCFC    RIVERSIDE COUNTY FLOOD CONTROL
RIRD    RYER ISLAND RECLAMATION DISTRICT                 
SCCS    SANTA CLARA COUNTY SURVEYOR                      
SDWD    SAN DIEGO WATER DISTRICT                         
SEWRPC  SE WISCONSIN REGIONAL PLANNING COMMISSION        
SFLWMD  SOUTH FLORIDA WATER MANAGEMENT DISTRICT          
SFWD    SAN FRANCISCO WATER DEPARTMENT                   
SJID    SAN JOAQUIN IRRIGATION DISTRICT                  
SRPE    SAVANNAH RIVER PLANT ENGINEER                    
SRVWUA  SALT RIVER VALLEY WATER USERS ASSOCIATION        
SVIP    SACRAMENTO VALLEY IRRIGATION PROJECT             
SWFWMD  SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT      
TID     TURLOCK IRRIGATION DISTRICT                      
TLAKE   TULARE LAKE IRRIGATION DISTRICT                  
TWWP    THE WASHINGTON WATER POWER COMPANY               
WACRM   WASHINGTON COUNTY REFERENCE MARK
WMATA   WASHINGTON METROPOLITAN AREA TRANSIT AUTH        
WSSC    WASHINGTON SUBURBAN SANITARY COMMISSION         

                                C-21
                              RAILROADS

SYMBOL  FULL NAME
****** 
***************************************************************
ACYRR   AKRON CANTON AND YOUNGSTOWN RAILROAD             
AGSRR   ALABAMA GREAT SOUTHERN RAILROAD                  
ATNRR   ALABAMA TENNESSEE AND NORTHERN RAILROAD          
ATSFRR  ATCHISON TOPEKA AND SANTA FE RAILROAD            
B+ARR   BOSTON AND ALBANY RAILROAD                       
BARR    BANGOR AND AROOSTOOK RAILROAD                    
BLERR   BESSEMER AND LAKE ERIE RAILROAD                  
BMRR    BOSTON AND MAINE RAILROAD                        
BNRR    BURLINGTON NORTHERN RAILROAD                     
BORR    BALTIMORE AND OHIO RAILROAD                      
BRPRR   BUFFALO ROCHESTER PITTSBURG RAILROAD             
CBQRR   CHICAGO BURLINGTON AND QUINCY RAILROAD           
CHWRR   CHESAPEAKE AND WESTERN RAILROAD                  
CIMRR   CHICAGO AND ILLINOIS MIDLAND RAILROAD            
CLGRR   COLUMBUS AND GREENVILLE RAILROAD                 
CMPPRR  CHICAGO MILWAUKEE ST PAUL AND PACIFIC RR         
CNJRR   CENTRAL OF NEW JERSEY RAILROAD                   
CNWRR   CHICAGO AND NORTH WESTERN RAILROAD               
CORR    CHESAPEAKE AND OHIO RAILROAD
CPRR    CANADIAN PACIFIC RAILROAD                        
CRNRR   CAROLINA AND NORTHWESTERN RAILROAD               
CVRR    CENTRAL VERMONT RAILROAD                         
DHRR    DELAWARE AND HUDSON RAILROAD                     
DLWRR   DELAWARE LACKAWANNA AND WESTERN RAILROAD         
DMIRRR  DULUTH MISSABE AND IRON RANGE RAILROAD           
DMRR    DETROIT AND MACKINAW RAILROAD                    
DRGWRR  DENVER AND RIO GRANDE WESTERN RAILROAD           
DTSRR   DETROIT AND TOLEDO SHORE LINE RAILROAD           
DWPRR   DULUTH-WINNIPEG AND PACIFIC RAILROAD             
ELRR    ERIE LACKAWANNA RAILROAD                         
ERIERR  ERIE RAILROAD                                    
FECRR   FLORIDA EAST COAST RAILROAD                      
GCSFRC  GULF COLORADO AND SANTE FE RAILWAY COMPANY       
GMORR   GULF MOBILE AND OHIO RAILROAD                    
GNRR    GREAT NORTHERN RAILROAD                          
GSFRR   GEORGIA SOUTHERN AND FLORIDA RAILWAY             
GTWRR   GRAND TRUNK WESTERN RAILROAD                     
GWRR    GREAT WESTERN RAILROAD                           
HRR     HUDSON RAILROAD                                  
ICRR    ILLINOIS CENTRAL RAILROAD                        
INTRR   INTERSTATE RAILROAD                              
KCSRR   KANSAS CITY SOUTHERN RAILROAD                    
LARR    LOUISIANA AND ARKANSAS RAILROAD                  
LIRR    LONG ISLAND RAILROAD                             
LNRR    LOUISVILLE AND NASHVILLE RAILROAD                
LVRR    LEHIGH VALLEY RAILROAD                           
MCRR    MICHIGAN CENTRAL RAILROAD                        
MKTRR   MISSOURI KANSAS TEXAS RAILROAD                   
MPRR    MISSOURI PACIFIC RAILROAD                        
NCRR    NASHVILLE CHATTANOOGA AND ST LOUIS RAILROAD      
NPRR    NORTHERN PACIFIC RAILROAD                        

                                C-22
                        RAILROADS - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
NSRR    NORFOLK SOUTHERN RAILROAD                        
NWPRR   NORTHWESTERN PACIFIC RAILROAD                    
NWRR    NORFOLK AND WESTERN RAILROAD                     
NYCRR   NEW YORK CENTRAL RAILROAD                        
NYNH+H  NEW YORK NEW HAVEN AND HARTFORD RAILROAD         
NYSLRR  NEW YORK CHICAGO AND ST LOUIS RAILROAD           
NYSWRR  NEW YORK SUSQUEHANNA AND WESTERN RAILROAD        
PCRR    PENN CENTRAL RAILROAD                            
PLERR   PITTSBURGH AND LAKE ERIE RAILROAD                
PMRR    PERE MARQUETTE RAILROAD                          
PRR     PENNSYLVANIA RAILROAD                            
PSFRR   PANHANDLE AND SANTA FE RAILWAY COMPANY           
RDGRR   READING RAILROAD                                 
RIRR    CHICAGO ROCK ISLAND AND PACIFIC RAILROAD         
RRR     RUTLAND RAILROAD                                 
SCLRR   SEABOARD COAST LINE RAILROAD                     
SDARR   SAN DIEGO AND ARIZONA EASTERN RAILWAY COMPANY         
SLSFRR  ST LOUIS SAN FRANCISCO RAILROAD                  
SLSWRR  ST LOUIS SOUTHWESTERN RAILROAD                   
SNRR    SACRAMENTO NORTHERN RAILROAD                     
SOORR   SOO LINE RAILROAD                                
SOURR   SOUTHERN RAILROAD                                
SPRR    SOUTHERN PACIFIC RAILROAD                        
TMRR    TEXAS MEXICAN RAILROAD                           
TNRR    TEXAS AND NORTHERN RAILROAD                      
TPRR    TEXAS AND PACIFIC RAILWAY                        
TPWRR   TOLEDO PEORIA AND WESTERN RAILROAD               
UPRR    UNION PACIFIC RAILROAD                           
VARR    VIRGINIA RAILWAY                                 
VTRR    VERMONT RAILROAD                                 
WARR    WESTERN OF ALABAMA RAILROAD                      
WLERR   WHEELING AND LAKE ERIE RAILROAD                  
WMRR    WESTERN MARYLAND RAILROAD                        
WPRR    WESTERN PACIFIC RAILROAD                         
Y+MVRR  YAZOO AND MISSISSIPPI VALLEY RAILROAD            
YVRR    YOSEMITE VALLEY RAILROAD                        


               UTILITY AND NATURAL RESOURCE COMPANIES

SYMBOL  FULL NAME
****** 
***************************************************************
AEP     AMERICAN ELECTRIC POWER                         
AGASEL  ASSOCIATED GAS AND ELECTRIC COMPANY
ALPCO   ALABAMA POWER COMPANY
AMOCO   AMOCO OIL COMPANY
AOCO    ASSOCIATED OIL COMPANY
APC     APPALACHIAN POWER COMPANY
ARFUEL  AR FUEL OIL COMPANY
ARLAGC  AR-LA GAS COMPANY
ASC     ALYSEKA SERVICE COMPANY

                                C-23
         UTILITY AND NATURAL RESOURCE COMPANIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
ATRECO  ATLANTIC REFINING COMPANY
BOCO    BELRIDGE OIL COMPANY
CHOCO   CHEVRON OIL COMPANY
CITGO   CITIES SERVICE COMPANY
CONED   CONSOLIDATED EDISON POWER COMPANY
CONOCO  CONTINENTAL OIL COMPANY
CONSPC  CONSUMER POWER COMPANY OF MICHIGAN
CREOLE  CREOLE PETROLEUM COMPANY
CTP+L   CONNECTICUT POWER AND LIGHT COMPANY
CVPS    CENTRAL VERMONT PUBLIC SERVICE CORPORATION
DECO    DETROIT EDISON COMPANY
DUKE    DUKE POWER COMPANY
FLPCO   FLORIDA POWER COMPANY
GAPC    GEORGIA POWER COMPANY
GPCC    GENERAL PETROLEUM CORPORATION OF CALIFORNIA
GULF    GULF REFINING COMPANY
HLPCO   HOUSTON LIGHTING AND POWER COMPANY
HOCO    HONOLULU OIL COMPANY
HUMBLE  HUMBLE OIL AND REFINING COMPANY
IMECO   INDIANA-MICHIGAN ELECTRIC COMPANY
LONESR  LONE STAR GAS COMPANY
LPCO    LAKEHEAD PIPELINE COMPANY
MINPCO  MICHIGAN NORTHERN POWER COMPANY
MOBIL   MOBIL OIL CORPORATION
MSP+L   MISSISSIPPI POWER AND LIGHT COMPANY
MWPLC   MICHIGAN-WISCONSIN PIPELINE COMPANY
NGPCA   NATURAL GAS PIPELINE COMPANY OF AMERICA
NJP+L   NEW JERSEY POWER AND LIGHT COMPANY
OHOCO   OHIO OIL COMPANY
OHPCO   OHIO POWER COMPANY
PEPCO   POTOMAC EDISON POWER COMPANY
PG+E    PACIFIC GAS AND ELECTRIC COMPANY
PHELCO  PHILADELPHIA ELECTRIC COMPANY
PHILIP  PHILLIPS PETROLEUM COMPANY
PP+L    PACIFIC POWER AND LIGHT COMPANY
PSCOCO  PUBLIC SERVICE COMPANY OF COLORADO
PSEG    PUBLIC SERVICE ELECTRIC AND GAS CO OF NEW JERSEY
PWPCO   PENNSYLVANIA WATER AND POWER COMPANY
ROCO    RICHFIELD OIL COMPANY
RPCO    REPUBLIC PRODUCTION COMPANY
SCE+G   SOUTH CAROLINA ELECTRIC AND GAS COMPANY
SCECO   SOUTHERN CALIFORNIA EDISON COMPANY
SCPA    SOUTH CAROLINA POWER AUTHORITY
SDG+E   SAN DIEGO GAS AND ELECTRIC COMPANY
SHELL   SHELL OIL COMPANY
SOCO    STANDARD OIL COMPANY
SOGCO   SIGNAL OIL AND GAS COMPANY
SOHIO   SOHIO PETROLEUM COMPANY
STOGC   STANOLIND OIL AND GAS COMPANY
SUNOCO  SUN OIL COMPANY
SUPOCO  SUPERIOR OIL COMPANY

                                C-24
         UTILITY AND NATURAL RESOURCE COMPANIES - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
TENNEC  TENNESSEE GAS AND PIPELINE COMPANY
TEXACO  TEXACO INCORPORATED
TWOCO   TIDEWATER OIL COMPANY
UNOLA   UNION TEXAS PETROLEUM
UOCO    UNION OIL COMPANY
VEPCO   VIRGINIA ELECTRIC POWER COMPANY
VOCO    VALVOLINE OIL COMPANY


          SURVEYING, ENGINEERING, AND CONSTRUCTION INDUSTRY

SYMBOL  FULL NAME
****** 
***************************************************************
AAS     ATLANTIC AERIAL SURVEYS                          
AASCO   ATLANTIS AERIAL SURVEY COMPANY                   
ABRAMS  ABRAMS AERIAL SURVEYS                            
ACFPS   ACF PRECISION SURVEYS INCORPORATED               
ADRGS   ADR GEODETIC SERVICES                           
AEROS   AERO SERVICE CORPORATION                         
AHI     ATWELL HICKS INC                                 
AIRSUR  AIR SURVEY CORPORATION                           
AISS    A I SILANDER AND SON                             
ALSTER  ALSTER AND ASSOCIATES ENGINEERS                  
AME     AERO-METRIC ENGINEERING INC                      
AMGEOD  AMERICAN GEODETIC SURVEY                         
ARCO    ATLANTIC RICHFIELD COMPANY                       
ASCPC   AMERICAN SURVEYING CONSULTANTS PC
B+OINC  BARBER AND OYLER, INCORPORATED                   
BAKER   M BAKER JR INC                                   
BANNER  BANNERMAN SURVEYORS INCORPORATED                 
BELL    BELL SURVEYING INCORPORATED                      
BENDIX  BENDIX CORPORATION
BESTOR  BESTOR ENGINEERS INC                             
BFEC    BENDIX FIELD ENGINEERING CORPORATION            
BFM     BFM CORPORATION                                  
BGAS    BRUCE AND GUNN AERIAL SURVEYS                    
BMMS    BOUTELLE MACFARLANE MEYER AND SELEE              
BOHUS   BOHANNAN-HUSTON INCORPORATED
BRADY   BRADY LAND SURVEYING INC                         
BRWE    BROCK AND WEYMOUTH ENGINEERS                     
BUN-Y   BURK + ASSOCIATES INC AND N-Y ASSOCIATES INC     
BSC     BSC GROUP-SURVEYING AND MAPPING INC              
BWDCO   BERKELEY WATERFRONT DEVELOPMENT COMPANY          
CANDA   CERVANTES AND ASSOCIATES                         
CAS     CARIBEAN AERIAL SURVEYS
CASSON  CASSON ENGINEERING COMPANY                       
CEJA    C E JOHNSON AND ASSOCIATES INC                   
CE+S    CALDWELL ENGINEERING AND SURVEYING               
CFM     C F MERRIAM SURVEYOR                             
CHAMBA  CHAMBLIN AND ASSOCIATES                          
CHANCE  JE CHANCE AND ASSOCIATES                         

                                C-25
    SURVEYING, ENGINEERING, AND CONSTRUCTION INDUSTRY - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
CHIAS   CHICAGO AERIAL SURVEY                            
CHIPPR  CHIPPERFIELD NAVIGATION SERVICES                 
CL      CLIFFORD LEISURE CIVIL ENGINEER                  
CMCO    CHARLES MAIN COMPANY                             
COLGOV  COLBURN AND GOVE CONSULTING ENGINEERS            
CREDAN  CREEGAN AND D ANGELO                             
CSMCI   C S MARINE CONSTRUCTORS INCORPORATED
CSPC    COLUMBUS SOUTHERN POWER COMPANY
CTMAIN  CT MAIN INCORPORATED                             
CTMALE  C T MALE ASSOCIATES                              
DAGSUR  DAGGETT SURVEYING INCORPORATED                   
DARA    D A RATEKIN AND ASSOCIATES                       
DEC     DAHLING ENGINEERING COMPANY                      
DECKER  R L DECKER                                       
DELTA   DELTA ENGINEERS INC                              
DENI    DENI ASSOCIATES INCORPORATED                     
DEWDAV  DEWBERRY DAVIS                                   
DUNLAP  DUNLAP ASSOCIATES                                
EDA     EARL DUDLEY ASSOCIATES INCORPORATED              
EESCC   E E STULLER CONSTRUCTION COMPANY                 
EGENG   EVANS-GRAVES ENGINEERS INC                       
EGPSSC  EAGLE GPS SURVEYING CORPORATION                  
ERLAND  ERLANDSEN AND ASSOCIATES
ESP     ENGINEERING SURVEYING AND PLANNING INC           
EQUINO  EQUINOX INC SURVEYING AND MAPPING                
EVANS   DAVID EVANS AND ASSOCIATES INCORPORATED          
EWB     E W BRAASCH CONSULTING ENGINEER                  
FAMC    FALCON AIR MAPS COMPANY                          
FAS     FAIRCHILD AERIAL SURVEYS                         
F+HINC  FLORENCE + HUTCHESON INCORPORATED                
FORBAC  FORD BACON AND DAVIS INCORPORATED                
FORSGN  FORSGREN AND ASSOCIATES
FWDRR   FORT WORTH AND DENVER CITY RAILWAY               
GAI     GERKINWOOD AND ASSOCIATES INCORPORATED           
GBLI    GORDON B LEWIS INC                               
GCS     GEODETIC CONSULTING SERVICES
GENES   GENESIS SURVEYING INCORPORATED (NOW GENGRP)                 

GENGRP  GENESIS GROUP INCORPORATED SE
GEOBAS  GEOBASE CONTROL INCORPORATED                     
GEOHYD  GEO-HYDRO INCORPORATED                           
GEOMET  GEOMETRICS GPS INCORPORATED                     
GEONEX  GEONEX ITECH INCORPORATED                        
GEOSER  GEODETIC SERVICES INCORPORATED
GHA     G HENKENHOFF AND ASSOCIATES                      
GREENW  RONALD GREENWELL AND ASSOCIATES
GREOMA  GREENHORNE-OMARA                                 
GRWAS   GRW AERIAL SURVEY                                
GSIGPS  GEOPHYSICAL SERVICE INCORPORATED                 
GWMSI   GEORGE W MUERY AND SON INCORPORATED              
HALSEY  W H HALSEY CIVIL ENGINEERS INC                   
HARMS   JOHN E HARMS JR AND ASSOCIATES INCORPORATED      

                                C-26
    SURVEYING, ENGINEERING, AND CONSTRUCTION INDUSTRY - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
HARTMN  HARTMANN ASSOCIATES INCORPORATED
HDA     HORTON DENNIS ASSOCIATES                         
HEIDT   HEIDT AND ASSOCIATES INCORPORATED                
HHAA    HELMER HUGHS AND ASSOCIATES
HLS     HUNTER LAND SURVEYING COMPANY                    
HOBBS   HOBBS AND ASSOCIATES                             
HOLDEN  HOLDEN GPS                                       
HTB     HEALY TIBBITS BUILDERS                           
HYCAS   HYCON AERIAL SURVEY                              
ISBELL  ISBELL CONSTRUCTION COMPANY                      
JAHA    JAMES H HARRIS AND ASSOCIATES
JBB     J B BLYDENBURGH SURVEYOR                         
JKPLS   JEFF KERN PROFESSIONAL LAND SURVEYOR             
JOHNSN  JOHNSON ENGINEERING INCORPORATED                 
KAISER  KAISER INDUSTRIES CORPORATION                    
KEISCH  KEITH AND SCHNARS - LAKELAND                     
KONSKI  KONSKI ENGINEERS                                 
LAFAVE  A LAFAVE LAND SURVEYOR                           
LDA     LEWIS DICKERSON AND ASSOCIATES CONS ENG          
LEAS    LIMBAUGH ENGINEERING AND AERIAL SURVEY INC       
LEGER   LEGER SURVEYS INC                                
LEVITT  ITT LEVITT CORPORATION                           
LIETZ   THE LIETZ COMPANY                                
LINDSY  F M LINDSEY AND ASSOCIATES                       
LOWE    LOWE ENGINEERS                                  
MADHOP  MADDOX AND HOPKINS SURVEYORS                     
MAI     MEYER AND ASSOCIATES INCORPORATED                
MARCHE  MARCHESE AND SONS                                
MARLOW  HARRY W MARLOW INCORPORATED                      
MASDIX  MASON AND DIXON                                  
MATOTA  WILLIAM MATOTAN AND ASSOCIATES                   
MCCENG  MCCLELLAND ENGINEERS                             
MCCRON  J R MCCRONE JR INC                               
MCTUER  MCCARTER AND TULLER INCORPORATED                 
MCGRIF  P C MCGRIFF COMPANY                              
MELGEE  MELVIN GEE AND ASSOCIATES                        
MERRIC  MERRICK AND COMPANY                              
METRIC  METRIC SURVEYS                                  
MGA     MOORE GARDNER AND ASSOCIATES                     
MGSINC  MINISTER AND GLAESER SURVEYING INC               
MHAS    MARK HURD AERIAL SURVEYS                         
MJH     MITCHELL JONES AND HARDEN INC                    
MKWS    M K WELCH SURVEYS                                
MLI     MILLER AND LUX INC                               
MME     MYERS-MACOMBER ENGINEERS                         
MPS     MACNAMEE PORTER AND SEELEY                       
MSAM    MOUNTAIN SURVEYING AND MAPPING INCORPORATED
MSE     MSE CORPORATION                                 
MSI     MEASUREMENT SCIENCE INCORPORATED
MSM     MEURER SERAFINI AND MEURER INCORPORATED  (NOW MSAM)          
 
NAVSER  NAVIGATION SERVICES INCORPORATED                 

                                C-27
    SURVEYING, ENGINEERING, AND CONSTRUCTION INDUSTRY - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
NEDIVS  NORTHEAST DIVERSIFIED SERVICES INCORPORATED      
OCEGPS  OCEONICS INCORPORATED                            
OMAN    OMAN CONSTRUCTION COMPANY                        
PAS     PARK AERIAL SURVEYS INC                          
PGEG    PETTY GEOPHYSICAL AND ENGINEERING COMPANY        
PHELPS  B E PHELPS INC                                   
PMC     PERRY C MCGRIFF COMPANY                         
PMGS    PHOTOGRAMMETRIC GEODETIC SURVEY                  
PORTER  NORMAN PORTER ASSOCIATES                         
POSER   POSITIONING SERVICES
PROENG       PROFESSIONAL ENGINEERING CONSULTANTS INCORPORATED
R+MCON  R + M CONSULTANTS INCORPORATED                   
RAYONI  ITT RAYONIER INCORPORATED                        
RDA     RINKER DETWILER AND ASSOCIATES                   
RSA     ROUSE-SIRINE ASSOCIATES                          
SBAS    SIDNEY B BOWNE AND SON                           
SBI     SHERWOOD BROTHERS INCORPORATED                   
SCAN    SCANLON AND ASSOCIATES                           
SCSC    SO CAROLINA SANTEE COOPER PS AUTHORITY           
SEC     SCHNEIDER ENGINEERING CORPORATION                
SECO    SOUTHERN ENGINEERING COMPANY                     
SELLS   CHAS H SELLS INC CONSULTING ENGINEERS            
SPAN    SPAN INTERNATIONAL INCORPORATED                  
SPEAR   JAY SPEARMAN CONSULTING ENGINEERS                
STEINA  STEINMAN AND ASSOCIATES                          
STUNTZ  STUNTZNER ENGINEERING AND FORESTRY               
SUNRIS  SUNRISE GEODETIC                                 
SURCON  SURVCON INCORPORATED                             
SURSAT  SURVSAT                                          
SURTEC  SUR-TECH INC                                     
SWECO   STONE WEBSTER ENGINEERING CORPORATION            
TCIRR   TENNESSEE COAL IRON AND RAILROAD COMPANY         
TE      THOMPSON ENGINEERING                             
THOMAS  THOMAS ENGINEERING AND SURVEYING COMPANY         
TNH     TRYCK NYMAN AND HAYES                            
TOTTEN  CARL TOTTEN ASSOCIATES                           
TOWILL  TOWILL INC                                       
TRIBBL  TRIBBLE AND RICHARDSON                          
TSI     TOBIN SURVEYS INCORPORATED                       
TURNER  A E TURNER ARCHITECT                             
TWT     TAYLOR WISEMAN AND TAYLOR CONSULTING ENGINEERS   
URS     URS COMPANY                                      
USKCE   UNWIN-SCHEBAN-KORYNTA CONS ENG                   
USSES   US SOIL EROSION SERVICE                          
VJV     V J VANLINT CONSULTING ENGINEER                  
VOGI    VOGI IVERS AND ASSOCIATES                        
WAA     WALKER AND ASSOCIATES INC                        
WALASS  WALLACE AND ASSOCIATES                           
WARD    E J WARD                                         
WAWHI   WALKER AND WHITEFORD INC                         
WBCC    WARREN BROTHERS CONSTRUCTION COMPANY             

                                C-28
    SURVEYING, ENGINEERING, AND CONSTRUCTION INDUSTRY - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
WESGEO  WESTERN GEOPHYSICAL COMPANY OF AMERICA           
WEVACO  WEST-VACO CORPORATION                            
WEYCO   WEYERHAEUSER COMPANY                             
WFTA    W F TURNEY AND ASSOCIATES                        
WHGAI   WILLIAM H GORDON ASSOCIATES INCORPORATED        
WHPCO   W H PORTER AND COMPANY INCORPORATED              
WIMPOL  WIMPOL INCORPORATED                              
WOOLPT  WOOLPERT CONSULTANTS                             
WRA     WHIGMAN AND REQUARDT ASSOCIATES                  
WSA     WILLIAMS AND STACKHOUSE ASSOCIATES               
YOUNG   GEORGE F YOUNG INCORPORATED                      
ZENA    ZENA COMPANY (ZEISS-JENA DISTR UNITED STATES)


                      EDUCATIONAL INSTITUTIONS

SYMBOL  FULL NAME
****** 
***************************************************************
BMS     BOSTON MUSEUM OF SCIENCE
BNL     BROOKHAVEN NATIONAL LABORATORY
CBI     CONRAD BLUCHER INSTITUTE FOR SURVEY AND SCIENCE 
CORUNI  CORNELL UNIVERSITY
CU      COLUMBIA UNIVERSITY
FSNSCH  FARMINGTON STATE NORMAL SCHOOL
GATECH  GEORGIA INSTITUTE OF TECHNOLOGY
IASUNI  IOWA STATE UNIVERSITY
JPL     JET PROPULSION LABORATORY
KSU     KANSAS STATE UNIVERSITY
LAFCOL  LAFAYETTE COLLEGE
LAHSCH  LOS ALTOS HIGH SCHOOL
LASLAB  LOS ALAMOS SCIENTIFIC LABORATORIES
LASU    LOUISIANA STATE UNIVERSITY
LAWRRI  LOUISIANA WATER RESOURCE RESEARCH INSTITUTE
LEHIGH  LEHIGH UNIVERSITY
MISCOL  MICHIGAN STATE COLLEGE
MIT     MASSACHUSETTS INSTITUTE OF TECHNOLOGY
MITU    MICHIGAN TECHNICAL UNIVERSITY
MSSU    MISSISSIPPI STATE UNIVERSITY
MSU     UNIVERSITY OF MISSISSIPPI
MUNIV   MARQUETTE UNIVERSITY
NDSU    NORTH DAKOTA STATE UNIVERSITY
ODU     OLD DOMINION UNIVERSITY
ORTI    OREGON TECHNICAL INSTITUTE
SCEC    SOUTHERN CALIFORNIA EARTHQUAKE CENTER
SUNIV   STANFORD UNIVERSITY
TCU     TEXAS CHRISTIAN UNIVERSITY
YUM     TECHNICAL UNIVERSITY OF MUNICH GERMANY
UALR    UNIVERSITY OF ARKANSAS AT LITTLE ROCK
UC      UNIVERSITY OF CALIFORNIA
UDE     UNIVERSITY OF DELAWARE
UFL     UNIVERSITY OF FLORIDA

                                C-29
                EDUCATIONAL INSTITUTIONS - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
UHI     UNIVERSITY OF HAWAII
ULAVAL  UNIVERSITY LAVAL QUEBEC
UMPQUA  UMPQUA COMMUNITY COLLEGE
UNAVCO  UNIVERSITY NAVSTAR CONSORTIUM
UNC     UNIVERSITY OF NORTH CAROLINA
UNM     UNIVERSITY OF NEW MEXICO
UNO     UNIVERSITY OF NEW ORLEANS
UTU     UNIVERSITY OF UTAH
UTX     UNIVERSITY OF TEXAS
UVA     UNIVERSITY OF VIRGINIA
UVC     UNIVERSITY OF VIRGINIA CONSERVANCY
UVT     UNIVERSITY OF VERMONT
UWI     UNIVERSITY OF WISCONSIN
WILCOL  WILLIAMS COLLEGE AT WILLIAMSTOWN MASSACHUSETTS
WVUNIV  WEST VIRGINIA UNIVERSITY


                PROFESSIONAL AND AMATEUR ASSOCIATIONS

SYMBOL  FULL NAME
****** 
***************************************************************
BSA     BOY SCOUTS OF AMERICA                           
ECM     ENGINEERS CLUB OF MEMPHIS                       
USPSQD  UNITED STATES POWER SQUADRON                  


      MISCELLANEOUS COMMERCIAL ORGANIZATIONS AND PRIVATE FIRMS

SYMBOL  FULL NAME
****** 
***************************************************************
AKGEO   ALASKAN GEOPHYSICAL                              
AKLPCO  ALASKA LUMBER AND PULP COMPANY                   
ATCO    ASSOCIATED TRACTION COMPANY                      
ATT     AMERICAN TELEPHONE AND TELEGRAPH COMPANY         
BGCO    BROWN GEOPHYSICAL COMPANY                        
BULE    BULE AND ASSOCIATES                              
BW      BRADFORD WASHBURN                                
BWCO    BONO-WILLIAMS COMPANY                            
CCCC    CARBIDE AND CARBON CHEMICALS CORPORATION         
CCICO   CLEVELAND CLIFFS IRON COMPANY                    
CH2M    CH2M HILL INCORPORATED                           
CLA     CROZER LAND ASSOCIATION                          
CPFC    CHAMPION PAPER AND FIBER COMPANY                 
CPI     CINCINNATI PRECISION INSTRUMENT COMPANY          
CROSET  CROSSETT LUMBER COMPANY                          
DBA     DBA SYSTEMS INCORPORATED                         
DOWCO   DOW CHEMICAL COMPANY                             
DSI     DESIGN SCIENCES INC                              
DVLCO   DOLLY VARDEN LUMBER COMPANY                      
ENVENG  ENVIRONMENTAL ENGINEERING INC                    
FMCO    FORD MOTOR COMPANY                               

                                C-30
MISCELLANEOUS COMMERCIAL ORGANIZATIONS AND PRIVATE FIRMS - CONTINUED

SYMBOL  FULL NAME
****** 
***************************************************************
GCC     GLOGORA COAL COMPANY                             
GE      GENERAL ELECTRIC CORPORATION                     
GEON    GEONAUTICS INC                                   
GRDC    GULF RESEARCH AND DEVELOPMENT COMPANY            
GWA     GERKEN WOOD AND ASSOCIATES INC                   
HAPT    HUGHES AIRPORT                                 
HMCO    HANNA MINING COMPANY                             
KETCH   KETCHIKAN PULP COMPANY                           
LAICO   LOS ANGELES INVESTMENT COMPANY                   
LDGO    LAMONT DOHERTY GEOLOGICAL OBSERVATORY            
LEICA   LEICA INCORPORATED
MACCO   MACCO CORPORATION                                
MCAM    MOLYBDENUM CORPORATION OF AMERICA                
MCLCO   MICHIGAN-CALIFORNIA LUMBER COMPANY               
MLGW    MEMPHIS LIGHT GAS AND WATER                      
NAAV    NORTH AMERICAN AVIATION                          
NJZINC  NEW JERSEY ZINC COMPANY                          
PACTT   PACIFIC TELEPHONE AND TELEGRAPH COMPANY          
PANAM   PAN AMERICAN AIRLINES                            
PCC     PEABODY COAL COMPANY                             
PECO    POHLY EXPLORATION COMPANY                        
PHILCM  PHILLIPS CHEMICAL COMPANY                        
PPCC    PACIFIC PORTLAND CEMENT CORPORATION              
PSOMAS  PSOMAS AND ASSOCIATES                            
PVE     PALOS VERDES ESTATES                             
REGIS   ST REGIS PAPER COMPANY                           
RRLC    RED RIVER LUMBER COMPANY                         
SANDIA  SANDIA CORPORATION                               
SLDC    SAINT LAWRENCE DEVELOPMENT CORPORATION           
SSC     SEISMOGRAPH SERVICE CORPORATION                  
STATEL  STANFORD TELECOM                                
SWBELL  SOUTH WESTERN BELL TELEPHONE COMPANY             
TLDYNE  TELEDYNE INCORPORATED                            
VAILCO  VAIL COMPANY                                     
VITRO   VITRO CORPORATION                                
WE      WESTERN ELECTRIC COMPANY                         
WHITE   WHITE PIGMENT COMPANY                            


                      NON-SPECIFIC DESIGNATORS 

SYMBOL  FULL NAME
****** 
***************************************************************
LOCENG  LOCAL ENGINEER (INDIVIDUAL OR FIRM)
LOCSUR  LOCAL SURVEYOR (INDIVIDUAL OR FIRM)
UNK     UNKNOWN PERSON OR FIRM






                                C-31



















                       INTENTIONALLY BLANK

































                              C-32
 

                              ANNEX D

        GUIDELINES FOR GEODETIC CONTROL POINT DESIGNATIONS


A geodetic control point is a monumented or otherwise marked,
survey point, established for the purpose of providing geodetic
reference for mapping and charting activities and for a wide
variety of engineering and scientific applications.  A control
point is normally identified by a number, an alphanumeric symbol,
or a concise, intelligible name which is usually stamped on the
disk marker.  In principle, the designation by which a control
point is identified should closely resemble the stamping that
appears on the respective marker.  However, extraneous information
is frequently present which should not be included as part of the
designation.  In every case, the designation assigned to a control
point for processing purposes must be identical to the designation
that appears in the heading of the station description.

These guidelines have been established to provide consistent
control point designations and facilitate automated processing of
the data.  Implementation of these guidelines may sometimes result
in two or more control points having the same designation.  In
such cases it will be necessary to refer to other information in
the description to completely identify the control point.  Sample
formats for the various designations are given in this annex. 


                            GUIDELINES

1.  A control point designation must not exceed 40 alphanumeric
characters, including all imbedded blanks.  When necessary,
abbreviate and/or edit an existing designation to conform to this
limit.

2.  The year the mark was set is considered extraneous information
and is not to be carried as part of a control point designation.
For marks whose designations have not been altered when they were
reset, the word RESET must be appended to the original
designations.  This also holds true for control points which have
been reset more than once. In such cases the year given in the
"year set" field will be used to distinguish the marks.

Monument            Stamped                       Designation

USGS BM Disk        TT 8 RESET 1965               TT 8 RESET
CGS BM Disk            LAKE WASHINGTON RESET 1970        LAKE
                                                     WASHINGTON
                                                     RESET
CGS Tri Sta Disk       BRADY 1951                    BRADY
CGS BM Disk            ONEAL 1 1954               ONEAL 1
CGS BM Disk            DE KALB 1934               DEKALB
NCGS Trav Sta Disk     MC CALL 1968               MCCALL
CGS Tri Sta Disk       DODGE 2 1969               DODGE 2
CGS Tri Sta Disk       SPIT 1953 1983                SPIT RESET
USGS Survey Disk       PRIM TRAV STA NO 185 1915     PTS 185





                                D-1
3.  The acronym or abbreviation of the agency or organization
whose name is precast or sometimes stamped in the survey marker is
considered extraneous information and should not be included in
the control point designation.

Monument             Stamped                   Designation

FLGS BM Disk         203 RESET 1950            203 RESET
FLGS BM Disk         203 RESET 1967            203 RESET
FLGS BM Disk         203 RESET 1967 MAY        203 RESET MAY
USGS BM Disk         2903                      2903      
MORC Gaging Sta      GAGING STA                GAGING STA
RIRR Disk            RV 16                     RV 16
USGS Chis Square                               WO 23 RM=148 RM
USGS Survey Disk     WO 23 1933                WO 23
USGS Survey Disk     WO 23 1933 RESET 1962     WO 23 RESET
PP+L Survey Disk     P 11 PPL RESET 1976       P 11 RESET


4.  The following special characters are the only ones allowed in
a control point designation.  They are the blank ( ), plus (+),
minus or hyphen (-), equals (=), slash (/), and decimal point (.). 
When used, these special characters must not be separated from
adjacent characters by any blanks.  Commas and parentheses are not
allowed within a designation.  


4.1  Most alpha and numeric character groupings in a designation
should be separated by a single blank ( ).  Some exceptions are
allowed, see the set of Abbreviations and Formats.

Monument             Stamped                   Designation

USGS Survey Disk     TT17B                     TT 17 B 
USGS Survey Disk     TT-17B                    TT 17 B 
USGS Survey Disk     TT-1 7B                   TT 1 7 B 


4.2  A plus sign (+) is permitted within a designation when the
control point was previously used for stationing in alignment
surveys.  In these cases the plus sign (+) must be immediately
preceded and followed by a digit, not a blank. 

Monument             Stamped                   Designation

AZDT Disk            STATION 11+14             ROUTE 244 STA 11+14
Highway Disk         2623 + 00                 I95 STA 2623+00


4.3  The minus or hyphen (-) is allowed only when indicating a
negative elevation stamped on a mark.  An elevation stamped on a
mark is used as the designation only when there is no other means
to identify the mark.  When a minus or hyphen (-) is used, it must
be the first character of the designation and must be immediately
followed by a digit. 
                     



                                D-2
Monument             Stamped                    Designation

USGS Nail (Tag)      -227.10 5-23-55            -227.10
CGS BM Disk          -193.097 F 70 1928         F 70
USGS BM Disk         ELEV -7.325 FT             -7.325 


4.4  The equal sign (=) is used as a separator for control points
which carry multiple stamped designations.  The designations
involved should be concatenated with the equal sign.  The combined
designation length must not exceed the 40-character limit and the
designation preceding the equal sign should be the designation
used by the originating agency.    


Monument             Stamped                    Designation

USGS Chis Square                                WO 23 RM=148 RM
CADH Survey Disk     CH 1174       297+00 (A)   CH 1174=297+00 A 
Unk Survey Disk      STA. NO. 3    MI. 182.5    STA 3=MI 182.5 
CGS Ref Mark Disk    LEE NO 1 1932 R 13         LEE RM 1=R 13
CGS Tri Sta Disk     68.399 B 22   ATKINSON 1918ATKINSON=B 22
USGS Cap             U 276 1942    VA 45 1917   45=U 276


NOTE:  In situations where there are multiple designations that
either do not appear stamped on the mark or are too long to be
accommodated by the 40-character designation, the secondary
designation may be given as a separate data item and carried as an
alias in the appropriate field.  

4.5  A slash (/) may be used to indicate a numerical fraction. 
Monument             Stamped                    Designation
USGLO Survey Disk     T1N R3E S35 S36 1/4 1943     T1N R3E SECS 35
36 1/4 COR

4.6  A period (.) may not appear imbedded in or adjacent to a
grouping of alpha characters, but may be used as a decimal point
if imbedded in (but not adjacent to) a grouping of numeric
characters.

Monument             Stamped                    Designation

MADPW Survey Disk    ELEV. B.M. NO. F 40        F 40
CGS Ref Mark Disk    W. BASE NO 4 1965          CHARLESTON W BASE
RM 4
CADWR Survey Disk    MI. 0.9 1967               AMERICAN CANAL MI
0.9 CGS Tri Sta Disk               PALMER N.E. BASE
                                   PALMER NE BASE
CGS BM Disk          MT. MORRIS 1941            
                     MT MORRIS

5.  Nonspecific descriptive terms are not to be treated as "double
designations" and are not to be carried as aliases. 




                                D-3             
Published as          Stamped                   Designation

BENCH MARK 2                                    2
114.3, Chis Square                              114.3
C 1, Bolt                                       C 1


6.  The characters "BM", "BENCH MARK", and "PBM", even when
stamped on a disk, are not to be included in a designation unless
the control point has no other stamping (e.g., BM USGS) or the
characters "BM" do not represent the words "BENCH MARK."


7.  The elevation stamped on the disk marker on the monument is
not to be carried as a part of the respective designation.  The
exception is when the elevation is the only means of identifying
the survey mark.

Monument              Stamped                   Designation

CGS BM Disk           H 325 230.695FT           H 325
MORC Disk             140B ELEV 95.3 FT         140 B 
USGS BM Disk          -9.825 FT                 -9.825 
BOR Survey Disk       ELEV. 101.6               101.6 


8.  The characters "NO" or "No.", when used as an abbreviation for
the word "number", should not be included in the designation, even
when they are stamped in the disk.

Monument              Stamped                   Designation

CGS Ref Mark Disk     MONROE NO 1 1944          MONROE RM 1
CGS BM Disk           BENCH MARK No. 6          6 


9.  The designation for a reference mark disk should be formed by
appending the symbols RM 1, RM 2, ..., RM 13, etc. to the name of
the horizontal control point for reference marks stamped NO 1, NO
2, ..., NO 13, etc., respectively. 

Monument              Stamped                   Designation

CGS Ref Mark Disk     CHARLOTTE NO. 1 1945      CHARLOTTE RM 1 
CGS Ref Mark Disk     BOULDER 1935 NO 6 1968    BOULDER RM 6
CGS Ref Mark Disk     CHICO 1948 NO 3 RESET 1971CHICO RM 3 RESET 


10.  The designation for an azimuth mark disk is formed by
appending the characters "AZ MK" to the name of the respective
horizontal control point.  In the case of multiple azimuth marks,
the numbers "2", "3", etc. are added for 
azimuth marks stamped NO 2, NO 3, etc. 






                                D-4             
Monument              Stamped                   Designation

CGS Az Mark Disk      CHARLOTTE 1934            CHARLOTTE AZ MK
CGS Az Mark Disk      BOULDER 1935 NO. 3        BOULDER AZ MK 3
CGS Az Mark Disk      NORWASH AZI 1932          NORWASH AZ MK
CGS Az Mark Disk      PARK AZ RESET 1965        PARK AZ MK RESET 


11.  A temporary bench mark (TBM) must carry the letters "TBM" as
the first three characters of the designation. 

Monument              Stamped                   Designation

Spike                                           
  TBM 1 A
Sidewalk                                        TBM 14


12.  The National Ocean Service (NOS) has instituted a standard
system of designations for all tidal and water level stations
operated by NOS.  The system provides for the unique
identification of all disks, staffs, etc., located at such
stations (e.g., see Formats in this annex).

Tidal and water level bench mark designations must conform to
standard designations adopted by the National Ocean Service.  For
information concerning specific tide gage bench marks, etc.,
communicate with:

     User Services Section, N/OES232
     National Ocean Service, NOAA
     1305 East-West Highway
     Silver Spring, MD 20910
     Telephone:  1-301-713-2877

Whenever the need arises for a guideline to deal with a situation
not covered herein, the user is encouraged to communicate with the
following appropriate technical offices in NGS:

     Horizontal Network Branch, N/CG12   
     National Geodetic Survey, NOAA   
     1315 East-West Highway
     Silver Spring, MD 20910
     Telephone:  1-301-713-3176
     
     Vertical Network Branch, N/CG13    
     National Geodetic Survey, NOAA   
     1315 East-West Highway
     Silver Spring, MD 20910
     Telephone:  1-301-713-3191
     
     Space and Physical Geodesy Branch, N/CG14
     National Geodetic Survey, NOAA   
     1315 East-West Highway
     Silver Spring, MD 20910
     Telephone:  1-301-713-3205



                                D-5
                             ABBREVIATIONS

A list of standard abbreviations has been adopted for use in
designating geodetic control points.  These abbreviations are for
terms that commonly occur in designations and are the only
accepted forms of abbreviation.  This list may be extended as the
need arises.

          __________________________________________________

             Geodetic control point abbreviations
          __________________________________________________

             A POINT                       A PT
             ACADEMY                       ACAD
             ADMINISTRATION                ADM
             AGENCY                        AGY
             AGRICULTURE                   AGRI
             AHEAD                      AHD
             AIRCRAFT                   ARCFT
             AIRPORT                       APT
             AIRWAY                        AWY
             AIR FORCE BASE                AFB
             ALLEGHENY                  ALGHNY
             AMBASSADOR                    AMB
             AMENDED                       AMD
             AMENDED MONUMENT (AM)         AMD MON
             AMERICAN                   AMER
             ANGLE                      ANG
             ANGLE POINT (AP)              ANG PT
             ANTENNA                       ANT
             APPALACHIAN                   APLCN
             APPROXIMATELY                 APPROX
             ASSOCIATION                   ASSOC
             ASTRONOMICAL               ASTRO
             ASYLUM                        ASY
             ATLANTIC                   AT
             AUTHORITY                  AUTH
             AUXILIARY                  AUX
             AUXILIARY MEANDER CORNER (AMC)    AUX MDR COR
             AVENUE                        AVE
          __________________________________________________

Notes:

1. Abbreviations listed with () are used by the Bureau of Land
Management.
2. The cardinal directions (E, S, W, N, NE, SE, SW, and NW) are to
be               abbreviated only when they are not the first word
of the designation.









                                D-6
          ____________________________________________________

            Geodetic control point abbreviations (Continued)
          ____________________________________________________

             AVIATION                   AVN
             AZIMUTH                    AZ
             BACK                       BCK
             BANK                       BK
             BANKING                    BKG          
             BAPTIST                    BAP                
             BATTERY                    BTRY               
             BEACON                     BCN                
             BEARING                    BRG                
             BEARING OBJECT (BO)        BRG OBJ            
             BEARING TREE (BT)          BRG TREE           
             BELFRY                     BFRY               
             BETWEEN                    BET                
             BOULEVARD                  BLVD               
             BOUNDARY                   BDRY               
             BREAKWATER                 BRKWTR             
             BRICK                      BR                 
             BROADCASTING               BCSTG              
             BROTHER                    BRO                
             BROTHERS                   BROS               
             BUILDING                   BLDG               
             BUREAU                     BUR                
             CAPITOL                    CAP                
             CATHEDRAL                  CATHL              
             CATHOLIC                   CATH               
             CEMETERY                   CEM                
             CENTER (C)                 CEN                
             CENTERLINE                 CL                 
             CERAMIC                    CERAM              
             CHEMICAL                   CHEM               
             CHIMNEY                    CHIM               
             CHURCH                     CH                 
             CLOCK                      CLK                
             CLOSING CORNER (CC)        CC                 
             COLLEGE                    COLL               
             COMMERCE                   COM                
             COMMERCIAL                 COML               
             COMMISSION                 COMM               
             COMPANY                    CO           
             COMPRESS                   COMP         
             CONCENTRATION              CONCN        
             CONCEPTION                 CON          
             CONCRETE                   CONC         
             CONGREGATIONAL             CONG         
            ____________________________________________________

                                                    




                                D-7
            ____________________________________________________

              Geodetic control point abbreviations (Continued)
            ____________________________________________________

             CONSOLIDATED               CONSOL       
             CONSTRUCTION               CONSTR       
             CONTINENTAL                CONTL        
             CONTROL                    CTRL         
             COOPERATIVE                COOP         
             CORNER                     COR          
             CORPORATION                CORP         
             CORRECTIONAL               CORR         
             COUNTRY                    CTRY         
             COUNTY                     CNTY         
             COURTHOUSE                 CTHSE        
             CUPOLA                     CUP          
             DAYBEACON                  DBCN         
             DEFENSE                    DEF          
             DEPARTMENT                 DEPT         
             DISTRIBUTOR                DISTR        
             DIVISION                   DIV          
             DOMESTIC                   DOM          
             DORMITORY                  DORM         
             DRAWBRIDGE                 DBRIDGE      
             EAST                       E            
             ECCENTRIC                  ECC          
             EDUCATION                  EDUC         
             ELECTRIC                   ELEC         
             ELEMENTARY                 ELEM         
             ELEVATION                  ELEV         
             ELEVATED                   ELEVD        
             ELEVATOR                   ELEVR        
             ENGINEERING                ENG          
             ENGRAVING                  ENGR         
             ENTRANCE                   ENTR         
             EPISCOPAL                  EPIS         
             EQUIPMENT                  EQPT         
             EVANGELICAL                EVAN         
             EXCHANGE                   EXCH         
             EXPERIMENTAL               EXPTL        
             FEDERAL                    FED          
             FINIAL                     FIN                
             FIRST                      1ST                
             FLAGPOLE                   FP                 
             FLAGSTAFF                  FS                 
             FOURTH                     4TH                
             FRONT RANGE                FRGE               
             FURNITURE                  FURN               
            ____________________________________________________






                                D-8
            ____________________________________________________

              Geodetic control point abbreviations (Continued)
            ____________________________________________________

             GABLE                      GAB
             GENERAL                    GEN                
             GEODETIC                   GEOD               
             GEOGRAPHIC                 GEOG               
             GEOLOGICAL                 GEOL               
             GOVERNMENT                 GOVT               
             GROWERS                    GROS               
             HARBOR                     HBR                
             HARDWARE                   HDWE               
             HEADQUARTERS               HQ                 
             HEIGHTS                    HTS                
             HIGHWAY                    HWY                
             HISTORICAL                 HIST               
             HOSPITAL                   HOSP               
             HOUSE                      HSE                
             HYDRO                      HYD                
             IMMACULATE                 IMM                
             IMPLEMENT                  IMPL               
             IMPORT                     IMP                
             INCINERATOR                INCIN              
             INCORPORATED               INC                
             INDEPENDENT                IND                
             INDUSTRIAL                 INDL               
             INDUSTRY                   INDY               
             INFIRMARY                  INFIRM             
             INSTITUTE                  INST               
             INSTITUTION                INSTN              
             INSURANCE                  INS                
             INTERNATIONAL              INTL               
             INTERSTATE                 INTST              
             INTERSECT                  INT                
             INVESTMENT                 INVT               
             IRRIGATION                 IRRIG              
             ISLAND                     IS                 
             JUNCTION                   JCT                
             LABORATORY                 LAB                
             LANDING                    LDG          
             LATITUDE                   LAT          
             LATTER DAY SAINTS          LDS          
             LEATHER                    LEA          
             LEFT                       LT **
            ____________________________________________________
            **The abbreviations R, T, LT, and RT must be
            adjacent to at least one numeric character.


                                                                   
                        



                                D-9
            ____________________________________________________

              Geodetic control point abbreviations (Continued)
            __________________________________________________

             LIGHT                      LT
             LIGHTHOUSE                 LH           
             LOCAL                      LCL          
             LOCATION                   LOC          
             LOCATION MONUMENT (LM)     LOC MON      
             LOOKOUT                    LO           
             LOOKOUT HOUSE              LOH          
             LOOKOUT TOWER              LOT          
             LONGITUDE                  LON          
             LUMBER                     LUM          
             LUTHERAN                   LUTH         
             MACHINERY                  MACH         
             MAGAZINE                   MAGZ         
             MAGNETIC                   MAG          
             MAINTENANCE                MAINT        
             MANUFACTURED               MFD          
             MANUFACTURING              MFG          
             MARK                       MK           
             MARKET                     MKT          
             MAST                       MST          
             MEANDER                    MDR          
             MEANDER CORNER (MC)        MDR COR      
             MERCHANDISE                MDSE         
             MERCANTILE                 MERC         
             METHODIST                  METH         
             METROPOLITAN               MET          
             MICROWAVE                  MV           
             MILE or MILES              MI           
             MILEPOST                   MP           
             MILITARY                   MIL          
             MILLING                    MILL         
             MONUMENT                   MON          
             MOUNT                      MT           
             MOUNTAIN                   MTN          
             MUNICIPAL                  MUN          
             MUSEUM                     MUS          
             NATIONAL                   NAT          
             NAVIGATION                 NAV          
             NEAR                       NR                 
             NORTH                      N                  
             NORTHEAST                  NE                 
             NORTHWEST                  NW                 
             OBJECT                     OBJ                
             OBSERVATION                OBS                
            ____________________________________________________

                                                  




                               D-10
            ____________________________________________________

              Geodetic control point abbreviations (Continued)
            ____________________________________________________

             OBSERVATORY                OBSY               
             OBSTRUCTION                OBSTR              
             OFFICE                     OFF                
             ORDNANCE                   ORD                
             ORGANIZATION               ORG                
             ORTHODOX                   ORTH               
             PEAK                       PK                 
             PENINSULA                  PEN                
             PETROLEUM                  PET                
             PINNACLE                   PCLE               
             PLANT                      PLT                
             POINT                      PT                 
             POINT A                    PTA                
             POINT OF CURVE             POC                
             POINT OF INTERSECTION      PI                 
             POINT OF TANGENT           POT                
             POLICE                     POL                
             POWER                      PWR                
             POWERHOUSE                 PHSE               
             PRESBYTERIAN               PRESB              
             PRIMARY                    PRIM               
             PRIMARY TRAVERSE STATION   PTS                
             PRINTING                   PTG                
             PROCESS                    PRCS               
             PRODUCING                  PRODG              
             PRODUCT                    PROD               
             PROPERTIES                 PROP               
             PROTESTANT                 PROT               
             PUBLIC                     PUB                
             PUBLISHING                 PUBG               
             QUARTER                    QTR                
             RADIO                      RAD                
             RAILROAD                   RR                 
             RAILWAY                    RWY                
             RANGE                      RGE                
             RANGE (Township)           R **                
             REAR RANGE                 RRGE               
             REFERENCE                  REF              
             REFERENCE MARK             RM           
             REFERENCE MONUMENT (RM)    REF MON      
             REFERENCE POINT            RP           
            ____________________________________________________
            **The abbreviations R, T, LT, and RT must be
            adjacent to at least one numeric character.







                               D-11
            ____________________________________________________

              Geodetic control point abbreviations (Continued)
            ____________________________________________________

             REFINING                   REFG
             REFORMED                   REFM         
             REFRIGERATING              REFRIG       
             RESET                      RST          
             RIGHT                           RT **           
             RIGHT OF WAY               ROW          
             ROAD                       RD           
             ROMAN                      ROM          
             ROUTE                      RTE
             RUNWAY                     RNWY         
             SAINT                      ST           
             SANITARY                   SANIT        
             SANITORIUM                 SAN          
             SAVINGS                    SVGS         
             SCHOOL                     SCH          
             SCHOOLHOUSE                SCHSE        
             SCIENTIFIC                 SCI          
             SECOND                     2ND          
             SECTION                    SEC          
             SECTIONS                   SECS         
             SEMINARY                   SEM          
             SERVICE                    SERV         
             SOCIETY                    SOC          
             SOUTH                      S            
             SOUTHEAST                  SE           
             SOUTHWEST                  SW           
             SPECIAL                    SPL          
             SPECIAL MEANDER CORNER (SMC)                          
SPL MDR COR  
             SPIRE                      SP           
             SQUARE                     SQ           
             STACK                      STK          
             STANDARD                   STD          
             STANDARD CORNER (SC)       SC           
             STANDPIPE                  SPIPE        
             STATION                    STA          
             STEEPLE                    STPE         
             STORAGE                    STGE         
             STREET                     STR          
             SUBURBAN                   SUBR         
             SUPERINTENDENT             SUPT         
             TANK                       TK                
            ____________________________________________________
            **The abbreviations R, T, LT, and RT must be
            adjacent to at least one numeric character.







                               D-12
            ____________________________________________________

              Geodetic control point abbreviations (Continued)
            ____________________________________________________

             TANGENT                    TAN               
             TANGENT OFFSET             TOS               
             TECHNICAL                  TECH              
             TELEGRAPH                  TELG              
             TELEPHONE                  TEL               
             TELEVISION                 TV                
             TEMP POINT A               TP A              
             TERMINAL                   TERM              
             TERRITORY                  TERR              
             THEOLOGICAL                THEO              
             THIRD                      3RD               
             TOWER                      TWR               
             TOWNSHIP                   TWP               
             TOWNSHIP (Tier)            T **               
             TRACT                      TR                
             TRANSCONTINENTAL           TRANSCON          
             TRANSMISSION               TRANSM            
             TRANSPORTATION             TRANSP            
             TRAVERSE                   TRAV              
             TRAVERSE STATION           TS                
             TRIANGLE                   TRI               
             TURNPIKE                   TPK               
             UNITARIAN                  UNIT              
             UNIVERSITY                 UNIV              
             VACUUM                     VAC               
             VERTEX                     VTX               
             VILLAGE                    VIL               
             WATER                      WT                
             WEST                       W                 
             WAREHOUSE                  WHSE              
             WINDMILL                   WMILL             
             WITNESS CORNER (WC)        WC                
             WITNESS POST (WP), wood    WP                
             WITNESS POST, metal        MWP
             WITNESS POST, fiberglass   FWP
            ____________________________________________________
            **The abbreviations R, T, LT, and RT must be
            adjacent to at least one numeric character.













                                     D-13
                                    FORMATS                        
     


Only NGS employees and agents may set brass disks and aluminum
flanges precast with NGS logo.  Such marks must be stamped with
designations supplied by the agency.  Each geodetic control point
designation should be unique among all the designations located
within a defined region.  


       Format                                        Page
       ________________________________________________________

       Geodetic Control Points                           D-15
       Tide Station Bench marks                      D-17
       Staffs or ETG RMs at Tide or Water-Level Stations D-19
       Water Level Station Bench Marks                   D-21
       Airport Runways                               D-23
       Political Boundaries                          D-24
       Highways and Roads                            D-25
       Railroads, Canals and Rivers                  D-26
       Landmarks                                  D-27
       Township and Range Control Point Information      D-28
       ________________________________________________________
          


















                        













                               D-14
                      Geodetic control points
__________________________________________________________________
____________

                    FORMAT:      NAME  SPECIAL
__________________________________________________________________
____________

1.  NAME

   A.  The following method is generally used for naming vertical
   control
       points (bench marks).  The first mark established in a state
       is
       designated "A", then "B" and so on through the alphabet,
       except the
       letters "I" and "O" which are not used because they are too
       easily 
       confused with the numbers "1" and "O".  The next series of
   marks is 
       identified as "A 1", "B 1", etc.; then "A 2", "B 2", etc.,
       and so on 
       through the alphabet.  In some cases, more than one letter
   is used
       to distinguish between bench marks that have accidentally
       been given
       the same name in the same state.

   B.  The following method is generally used for naming a
   horizontal
       control point (triangulation or traverse).  The name should
       serve
       not only to identify the station but to suggest the local
       geographic
       location or feature.  The name should be used only once
       within a
       county and preferably a given state.  Therefore, use
       sufficient
       variety to avoid duplication.  A short name is desirable,
       but if a
       longer name is required to properly serve the purpose, it
       should be
       used. In those cases where a well known geographical feature
       in the vicinity is used, or the name of a local landowner,
       the name should
       be spelled correctly.

2.  SPECIAL USE

   A.  These terms are used with vertical control points to
   distinguish
       between names used more than once in a state or to indicate
       disturbance of the original bench mark (e.g., "RESET").

   B.  These terms are used with horizontal control points to
   explain a
       local use or disturbance to the original mark or its
       designation.
__________________________________________________________________
__________


















                               D-15
                             Examples:

                     Geodetic control points 
                 --------------------------------------------  
                 NAME                          SPECIAL
                 --------------------------------------------
                 Station             |  Number |  Use
                 --------------------+-----------+-----------
                 A               |         |
                 L               | 690     |
                 L               | 690     | RESET
                 YY              | 1150        |
                 C               | 1244        | X
                 LEON            |         |
                 LEON            |         | ECC
                 LEON            |         | RESET
                 LEON            | RM 1        |
                 LEON            | RM 2        |
                 LEON            | AZ MK       |
                 LEON            | AZ MK       | RESET
                 LEON            | AZ MK       | PTA
                 LEON            | AZ MK 2 |
                 LEON 2              |         |
                 LEON 2              | RM 3       |
                 LEON 2              | RM 4       |  
                 LEON 2              | AZ MK      |
                 LEON 2              | AZ MK 2 |
                 --------------------------------------------




























                               D-16
                   Tide station bench marks
__________________________________________________________________
____________

             FORMAT:      LOCATION  OBJECT  SPECIAL
__________________________________________________________________
____________

1.  LOCATION Code and Station

   A.  The location has two parts, the first part, the CODE, is
   a 3-digit State code given for each geographical region.
   B.  The second part of the location, the STATION NUMBER, is
   an unique 4-digit number assigned to a particular tide
             station within a given
      geographical area.

2.  OBJECT Identification

   A.  The MARK USE gives information on the nature of the
   object which was used.
   B.  The PUBLICATION NAME is used to give the proper
   identification of theobject.  In most cases, this field
                       should be based on the stamping.  If
                       there is no stamping, use the name given
                       in the tidal publication.  In either
                       case, this field is subject to the
                       guidelines given in this Annex.

3.  SPECIAL Use

   This term is used to explain a local use or disturbance to
   the original mark.

   NOTE: If other types of marks are used in tidal surveys, see
   other format rules for their primary designations; and add
   aliases according to the following examples:

          Mark type           DS (Triangulation Station Mark)
          Stamping            BREACH 1963
          Primary designation    BREACH        
          Alias               866 5552 TIDAL    

          Mark type           DB (Bench Mark Disk)
          Stamping            V 163 RESET 1984
          Primary designation    V 163 RESET
          Alias               872 9871 TIDAL
_________________________________________________________________
_____________
                         












                              D-17                     
                            Examples

        Tide station bench marks set before or about 1976
         
--------------------------------------------------------------  
              LOCATION           OBJECT                    
SPECIAL
         
-------------------------------------------------------------- 
          Code   | Station    | Mark  | Identification       |
Use    
          State  | No.     | use   | Publication name     |     
         --------+------------
+-------+----------------------+---------  
          866    | 1684                       | TIDAL | HB 1      
          |      
          857    | 4680                       | TIDAL | BASIC     
          |      
          872    | 0030                       | TIDAL | 37        
          | RESET
          944    | 0886                       | TIDAL | USE 5     
          |      
         
--------------------------------------------------------------  


          Tide station bench marks set after about 1976
         -
-------------------------------------------------------------
               LOCATION          OBJECT                    
         SPECIAL
         -
         -------------------------------------------------------
         ------
          Code   | Station   | Identification       | Mark  | Use 
  
          State   | No.    | Publication name     | use   |     
         
--------------------------------------------------------------
          872    | 0051    | D                | TIDAL |      
          872    | 9554    | C                | TIDAL | RESET
         
--------------------------------------------------------------






























                              D-18
        Staffs or electric tape gage (ETG) reading marks 
                 at tide or water-level stations
_________________________________________________________________
_____________

          FORMAT:      TEMPORAL  LOCATION  OBJECT  SPECIAL
_________________________________________________________________
_____________

1.  TEMPORAL Reference

   The Temporal Reference is identified by setting the term
   "TBM" in front of the location.

2.  LOCATION Code and Station

   A.  The location has two parts, the first, the CODE, is
   either a 3-digit STATE number code for a State or a
                    3-digit CUTTER code for defining a
      part of a lake or channel.
   B.  The second part of the location, the STATION NUMBER, is
   an unique    4-digit number assigned to a particular tide
                or water level station
      within a given geographical area.

3.  OBJECT Identification

   The Object Identification gives information on the nature of
   the object
   that was used.

4.  SPECIAL Use
   These terms are used to indicate the graduation of the tide
   or water
   level staff on which the level rod was placed.
_________________________________________________________________
_____________














                        











                              D-19
                            Examples

                          Staffs located at tide stations
------------
---------------------------------------------------------------
  TEMPORAL     LOCATION                             OBJECT 
SPECIAL
-----------------------------------------------------------------
----------
  Reference  | Code             | Station              |
             Identification|Use
             | State            | No.                  ||
-----------------------------------------------------------------
----------
   TBM       | 872              | 2029                 |    
                                STAFF               | 6 FT 
             |                  |                      ||      
-----------------------------------------------------------------
----------


Electric (or "zero electric") tape gage reading marks at tide
stations
-----------------------------------------------------------------
----------
  TEMPORAL     LOCATION                             OBJECT 
SPECIAL
-----------------------------------------------------------------
----------
  Reference  | Code             | Station              |
             Identification     |  Use
             | State            | No.                  ||
-----------+--------+-----------+------------------------------+-
----------
   TBM   | 872            | 9678                       |     ETG
READ MK  |      
             |                  |                      ||      
-----------------------------------------------------------------
----------


                Staffs located at water level stations 
-----------------------------------------------------------------
----------
  TEMPORAL     LOCATION                             OBJECT 
SPECIAL
-----------------------------------------------------------------
----------
  Reference  | Code             | Station              |
             Identification     |  Use
             | Cutter | No.                         |  |
-----------+--------+-----------+------------------------------+-
----------
   TBM   | 906            | 3000                       |    
STAFF    | 6 FT 
             |                  |                      ||      
-----------------------------------------------------------------
----------


         Electric tape gage (ETG) reading marks at water level
stations
-----------------------------------------------------------------
----------
  TEMPORAL  |     LOCATION                          |  OBJECT| 
SPECIAL
-----------+--------+-----------+------------------------------+-
----------
  Reference  | Code             | Station              |
             Identification     |  Use
             | Cutter | No.                         |  |
-----------+--------+-----------+------------------------------+-
----------
   TBM   | 907            | 5099                       |     ETG
READ MK  |      
             |                  |                      ||      
-----------------------------------------------------------------
----------
                                                    


                                                    




                              D-20

                Water level station bench marks
______________________________________________________________________
________

             FORMAT:      LOCATION  OBJECT  SPECIAL
______________________________________________________________________
________


1.  LOCATION Code and Station 

   A.  The  first part of the location is the 3-digit code for
   defining a 
      part of a lake or channel within the CUTTER Code System.
   B.  The second part of the location, the STATION NUMBER, is a
   unique
      4-digit number assigned to the water level station within
      a given
      geographical area.

2.  OBJECT Identification

   In most cases, this field should be based on the stamping. 
   If there 
   is no stamping, use the name given in the water level
   publication.
   In either case, this field is subject to the guidelines given
   in this 
   annex.

3.  SPECIAL Use

   These character strings are used to explain some local use or
    disturbance to the original mark.

   NOTE: If other types of marks are used in water level
   surveys, see other
   format rules for their primary designation and add an alias
   according
   to the following example:

      Mark type        F            (flange-encased rod)
      Stamping         C 234 1980       (on logo cap)
      Primary designation C 234         
      Alias            906 3087
_________________________________________________________________
_____________









                           









                              D-21
                            Examples

      Water level station bench marks set before or about 1976
   -------------------------------------------------------------
   -----
      LOCATION         OBJECT                     SPECIAL
   -------------------------------------------------------------
   ----- 
   Code   | Station |  Identification         |   Use    
   Cutter    | No      |                      |
   --------+-----------+---------------------------+------------
   -  
    907   | 5098       |  ROAD A                  |
    907   | 5098       |  ROAD A                  |  RESET
   -------------------------------------------------------------
-----  



          Water level station bench marks set after about 1976
   
-----------------------------------------------------------------
- 
      LOCATION         OBJECT                     SPECIAL
   -------------------------------------------------------------
----- 
   Code   | Station |   Identification        |  Use    
   Cutter    | No.     |                      |             
   -------------------------------------------------------------
   -----
   907       | 5085       | F                        |      
   907       | 5085       | F                        |  RESET
   -------------------------------------------------------------
   -----  

   





























                              D-22
                
                         Airport runways
_________________________________________________________________
_____________

          FORMAT:     ALIGNMENT  OBJECT  LOCATION  SPECIAL
_________________________________________________________________
_____________

1.  ALIGNMENT Survey Name

   Use the proper NAME of the town, city, or a geographic
   location        within the area for the airport.

2.  OBJECT Identification

   Enter the type of alignment object, in this case it is the
   airport     RUNWAY.

3.  LOCATION Station (Runway Number) and Tangent Offset (TOS)

   A.  The location has two parts, the first part is called the
   runway       number and should be a 2-digit numerical
                value.  These two digits 
      are taken from the first two digits of the 3-digit runway
(measured 
      from north) azimuth, i.e., 01, 13, 22, or 34 which were
taken from the      azimuths of 010, 130, 220, and 340
respectively.

   B.  The second part of the location, the tangent offset
      (TOS), is the      location of the control point in
      question with respect to the center 
      of the alignment, that is, the distance (in meters/feet)
either left 
      or right.  

4.  SPECIAL Use

   Terms such as A PT, ECC, HUB, PTA, RESET, and TP A are used
   to         explain a local use or disturbance to the original
   mark.
_________________________________________________________________
_____________


                            Examples

                         Airport runways
-----------------------------------------------------------------
----------
ALIGNMENT                   OBJECT           LOCATION         
SPECIAL
-----------------------------------------------------------------
----------
Survey name          |  Identification  | Station |   TOS   | 
Use
---------------------+------------------+---------+---------
+--------------
KENNEWICK AIRPORT    |                  |         |         |
KENNEWICK AIRPORT    |                  |         |         | 
ECC
KENNEWICK AIRPORT    |                  |         |         |
RESET
KENNEWICK APT AZ MK  |                  |         |         |
KENNEWICK APT        | RUNWAY           | 00      | OFFSET  | HUB
KENNEWICK APT        | RUNWAY           | 36      | CL      |
KENNEWICK APT        | RNWY             | 02      | CL      |
KENNEWICK APT        | RNWY             | 20      | CL      |
-----------------------------------------------------------------
----------


                              D-23
                      Political boundaries
_________________________________________________________________
_____________

      FORMAT:       ALIGNMENT  OBJECT  DESIGNATE  POLITICAL 
SPECIAL
_________________________________________________________________
_____________

1.  ALIGNMENT Survey 

   The term BOUNDARY is used when two or more participants are
   in common 
   or adjacent to an alignment.

2.  OBJECT Identification

   Enter the type of alignment object, such as name, station,
   miles,      mileposts, monuments, reference points, etc.

3.  DESIGNATE Reference

   The designate reference is used to identify the unique
   number,         letters, or symbols that describe the control
   point.

4.  POLITICAL Participants

   A.  All participants in common or adjacent to the alignment
   boundary
      are listed in alphabetical order.
   B.  The political participants to be selected and entered
   first will
      be by the following order: international, federal,
      reservations,
      state, county, municipal, and private.
   C.  The selection order will provide the correct entries for
   the
      country/state and county fields used within the NGS data
      base.

5.  SPECIAL Use

   Terms such as A PT, ECC, HUB, PTA, RESET, and TP A are used
   to         explain a local use or disturbance to the original
   mark.
_________________________________________________________________
_____________

                            Examples

                      Political boundaries
-
-----------------------------------------------------------------
----
ALIGNMENT         OBJECT          DESIGNATE    POLITICAL     
SPECIAL
-----------------------------------------------------------------
-----
Survey     |  Identification   | Reference |  Participants |  
Use
-----------|---
----------------|-----------|---------------|----------
BOUNDARY   | MONUMENT          | 84 A      | MX US         |
RESET
BOUNDARY   | MILEPOST          | 360       | ND SD         |
BOUNDARY   | TRAVERSE STATION  | 110 A     | CD US         | ECC
BOUNDARY   | ARC STONE         | 14        | DE PA         |
RESET
BOUNDARY   | CORNER STONE      | 2         | MD PA         |
BOUNDARY   | TANGENT STONE     | 1         | DE MD         |
BOUNDARY   | INTERSECT STONE   | OFFSET    | DE PA         |
BOUNDARY   | POINT             | 24        | CD US         |
BOUNDARY   | REFERENCE POINT   | 22        | AZ CA         |
-----------------------------------------------------------------
-----

                              D-24
                       Highways and roads
_________________________________________________________________
_____________

          FORMAT:        ALIGNMENT  OBJECT  LOCATION  SPECIAL
_________________________________________________________________
_____________

1.  ALIGNMENT Survey Name

   A.  Use the term Ixxx for all Interstate highways.
   B.  Use the term HIGHWAY for all Federal highways.
   C.  Use the term ROUTE for all State highways.
   D.  Use the term ROAD for all county roads.
   E.  Use the municipality name for all local streets, avenues,
      boulevards, pikes, roads, etc.

2.  OBJECT Identification

   A.  Enter the type of alignment object, such as the name and
   station,
      miles, mileposts, monuments, reference points, etc.
   B.  Or enter the proper name of the alignment, such as the
   name of the
      city street.

3.  LOCATION Station and Tangent Offset

   A.  The location uses two parts, the first part is called the
      stationing.  This part should be, for most cases, a
      numeric value.
   B.  The second part of the location, the tangent offset
   (TOS), is the
      location of the point in question with respect to the
      center of
      the alignment, that is, the distance (in meters/feet)
      either left
      or right.

4.  SPECIAL Use

   Terms such as A PT, ECC, HUB, PTA, RESET, and TP A are used
   to explain a local use or disturbance to the original mark.
_________________________________________________________________
_____________


                            Examples
                       Highways and roads
-----------------------------------------------------------------
-----
ALIGNMENT             OBJECT            LOCATION          SPECIAL
-----------------------------------------------------------------
-----
Survey name    |  Identification  |   Station   |   TOS     | 
Use
---------------|------------------|-------------|-----------
|---------
I495           | MILEPOST         | 99.387      |           | ECC
HIGHWAY 50     | STATION          | 1234+00     | CL        |
ROUTE 355      | STATION MARK     | 233+16      | 50LT      |
ROUTE 193      | REFERENCE POINT  | 21+00       | POC       |
ROAD 2786      | MILEPOST         | 37.3        |           |
RESET
ROCKVILLE      | MAPLE AVE STA    | 1+32        | 39RT      |
ROCKVILLE      | MAPLE AVE STA    | 2+50        | POT       |
PASCO          | MAIN STREET      | PI 9        |           |
-----------------------------------------------------------------
-----


                              D-25

                  Railroads, canals and rivers
_________________________________________________________________
_____________

      FORMAT:       ALIGNMENT  OBJECT  LOCATION  SPECIAL
_________________________________________________________________
_____________

1.  ALIGNMENT Survey

   A.  The terms RAILROAD or RAILWAY for alignments which follow
   these
       right-of-ways.
   B.  Use the characters CANAL or REACH for those man made
   waterways.
   C.  Use the characters RIVER for all natural waterways.

2.  OBJECT Identification

   Enter the type of alignment object, such as name, station,
   miles,
   mileposts, monuments, reference points, etc.

3.  LOCATION Station and Tangent Offset

   A.  The location uses two parts, the first part is called the
      stationing.  This part should be, for most cases, a
      numeric value.

   B.  The second part of the location, the tangent offset
   (TOS), is the
      location of the point in question with respect to the
      center of
      the alignment, that is, the distance (in meters/feet)
      either left
      or right.

4.  SPECIAL Use

   Terms such as A PT, ECC, HUB, PTA, RESET, and TP A are used
   to explain
   a local use or disturbance to the original mark.
_________________________________________________________________
_____________


                            Examples

                  Railroads, canals and rivers
-----------------------------------------------------------------
-
ALIGNMENT    OBJECT              LOCATION         SPECIAL
-----------------------------------------------------------------
-
Survey     |  Identification |   Station    |   TOS     |   Use
-----------|-----------------|--------------|-----
------|---------
RAILROAD   | MILEPOST        | 347.8        | CL        | RESET
RAILWAY    | MILEPOST        | 216.455      | OFFSET    |
REACH      | 1               | 22+00        | 400LT     | ECC
REACH      | 1               | PI 2         |           |
REACH      | 3               | 295+00       | 400LT     |
RIVER      | SNAKE MILEPOST  | 37.3         |           |

--------
----------------------------------------------------------




                              D-26
                            Landmarks
_________________________________________________________________
_____________

             FORMAT:       LOCATION  OWNERSHIP  OBJECT  SPECIAL
_________________________________________________________________
_____________

1.  LOCATION

   A.  The general area in which the landmark is located should
   be used,     such as the nearest city, town, or local
                geographic area.
   B.  However, some landmarks by the nature of their name alone
   will be      enough to give a general location, e.g.
                STATUE OF LIBERTY (New York),  SEARS TOWER
                (Chicago), and SEATTLE SPACE NEEDLE (Seattle).

2.  OWNERSHIP

   A.  The ownership should be the proper name of the existing
   owner at the 
      time the landmark was positioned.  Later recovery
   information will 
      reflect the changes of ownership.
   B.  If the ownership is a political group, such as a state or
   county, do 
      not include the name of the state or county.

3.  OBJECT Identification
   For a landmark, enter a general name in order to identify it.

4.  SPECIAL Target
   The special target is used to uniquely identify the exact
   object       sighted as the landmark. 
_________________________________________________________________
_____________

                            Examples
                            Landmarks
-----------------------------------------------------------------
-------------   LOCATION  |    OWNERSHIP           |      OBJECT  
         |  SPECIAL
             |                        +------------------------
+--------------
             |                        |     Identification     | 
Target
-------------+------------------------+------
------------------+--------------
ASHLAND      | MUNICIPAL              | AIRPORT                |
BEACON
BETHESDA     | GREEK ORTHODOX         | CHURCH                 |
CROSS
CARSON CITY  | STATE POLICE           | RADIO STATION          |
MAST 
FRANKLIN     | COUNTY                 | HOSPITAL               |
FLAGPOLE
KEY WEST     | FORT MONROE            | BATTERY                |
RED LIGHT
LAS VEGAS    |                        | TV STATION KLAS        |
MAST
LOVELOCK     |                        | RADIO STATION KOB 893  |
MAST
NEW YORK     | PORT AUTHORITY         | BUILDING               |
FLAGPOLE
PASCO        | COUNTY                 | COURTHOUSE             |
DOME
POTOMAC      | ST MARKS CATHOLIC      | CHURCH                 |
SPIRE
ROCKVILLE    | HUGHES AIRCRAFT        | BUILDING               |
APEX
ROCKVILLE    | MUNICIPAL              | GAS TANK               |
FINIAL
ROCKVILLE    | MUNICIPAL              | WATER TANK             |
BALL
ROCKVILLE    | MUNICIPAL              | STANDPIPE              |
FINIAL
SALEM        | 1ST METHODIST          | CHURCH                 |
WEST SPIRE
SALEM        | STATE                  | HOSPITAL CLOCK         |
APEX
WINNEMUCCA   |                        | RADIO STATION KWNA     |
MAST
-----------------------------------------------------------------
-------------
                              D-27
          Township and range control point information 
_________________________________________________________________
_____________

             FORMAT:      TOWNSHIP  RANGE  SECTION  LOCATION
_________________________________________________________________
_____________

Department of Interior, Bureau of Land Management disks are
always marked by stamping them so as to be read looking north
while standing on the south side.  This relationship gives the
viewer a pictorial or graphical representation of 
the physical relationship of the existing subdivision of the land
under survey.

The south and east boundaries of each township, for the most
part, are the controlling sides, whereas north and west township
boundaries will close onto 
the controlling standard parallel to the north and the guide
meridian to the 
west of it respectively.

1.  TOWNSHIP

   A. One Township #
      Indicate the Township containing the identified survey
      monument.
   B. Two Townships ## (read from south to north)
      (1)  List southernmost FIRST (one with lowest latitude)
      (2)  List northernmost SECOND (one with higher latitude)

2. RANGE

   A. One Range #
      Indicate the Range containing the identified survey
      monument.
   B. Two Ranges ## (read from west to east)
      (1)  List Range on the left FIRST (western most)
      (2)  List Range on the right SECOND (eastern most)
   
3.  SECTION

   A. Arrange and list all sections to be included, in a string
      of increasing section numbers.
   B. For Township surveys which are incomplete, show the
      identification  (see part 4) as a Cardinal Corner of the
      "One" lowest section where the subdivision survey has been
      completed.

4. LOCATION - Identification of a Subdivision Survey Point

   A.  Standard Corner                  S C
   B.  Closing Corner                   C C
   C.  Meander Corner                   M C
   D.  Quarter-Section Corner              1/4 COR
   E.  Location Monument                L M
   F.  Angle Point                      A P
   G.  Witness Corner                   W C
   H.  Cardinal Corner                  ***
   I.  Identification as Found             NIR S180 MP31
_________________________________________________________________
_____________
***Use Lowest Section Number Completed.     


                              D-28
     |    |    |    |    |   |                            |
     |  4TH STD PARALLEL NORTH (96 miles)                 |
     + -- + -- + -- + -- + --
+---------------------------+------
   N |    |    |    |    |    |      |      |      |      |
   O |    F    S    3    4   5|      |      |      | T16N |6
   R |    I    E    R    T   T|      |      |      | R24E |T
   T |    R    C    D    H   H|      |      |      |      |H
   H |    S    O              |------|------|------|------|
      |    T    N    |    |   G|      |      |      |      |G
      |         D    |    |   U|      |      |      | T15N |U
     |    |         |    |   I|      |      |      | R24E |I
   P |    |    |    |    |   D|      |      |      |      |D
   R |                       E|------|------+******+------|E
   I |                        |      |      *      *      |
   N |                       M|      |      * T14N * T14N |M
   C |                       E|      |      * R23E * R24E |E
   I |                       R|      |      *      *      |R
   P |                       I|------|------+******+------|I
   A |                       D|      |      |      |      |D
   L |                       I| T13N | T13N | T13N | T13N |I
     |    |    |    |    |   A| R21E | R22E | R23E | R24E |A
     |    |    |    |    |   N|      |      |      |      |N
    M + -- + -- + -- + -- + --
+---------------------------+------
   E |  3RD STD PARALLEL NORTH (72 miles)                 |
   R |                        |                           |
   I |
   D + -- + -- + --
   I |  SECOND STD PARALLEL NORTH (48 miles)
   A |
   N |
     + -- + -- + --
     |     FIRST STD PARALLEL NORTH (24 miles)
     |
      |
     + -- + -- BASE LINE          
     |\
   S | \ (INITIAL POINT)
   O |
   U |
   T |  FIRST STD PARALLEL SOUTH (24 miles)
   H + -- + -- + -- 
     |

   Figure D.1 - Layout of Standard Parallels and Guide
   Meridians.












                              D-29
T15N R22E |                T15N R23E                | T15N R24E
   36    |  31  |  32  |  33  |  34  |  35  |  36  |    3
          |      |      |      |      |      |      |
--------- +******+******+******+******+******+******+ ----------
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
     1    *   6  |   5  |   4  |   3  |   2  |   1  *    6
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
       -- +------+------+------+------+------+------+ --
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
    12    *   7  |   8  |   9  |  10  |  11  |  12  *    7
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
       -- +------+------+------+------+------+------+ --
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
    13    *  18  |  17  |  16  |  15  |  14  |  13  *   18
          *      |      |             |      |      *
T14N      *      |      |    T14N     |      |      *      T14N
R22E   -- +------+------+--- R23E ----+------+------+ --   R24E
          *      |      |             |      |      *
          *      |      |      |      |      |      *
    24    *  19  |  20  |  21  |  22  |  23  |  24  *   19
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
       -- +------+------+------+------+------+------+ --
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
    25    *  30  |  29  |  28  |  27  |  26  |  25  *   30
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
       -- +------+------+------+------+------+------+ --
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
    36    *  31  |  32  |  33  |  34  |  35  |  36  *   31
          *      |      |      |      |      |      *
          *      |      |      |      |      |      *
----------+******+******+******+******+******+******+-----------
          |      |      |      |      |       |     |
     1    |   6      5      4      3      2      1  |    6
T13N R22E |                T13N R23E                | T13N R24E


 Figure D.2 - T14N R23E SECS (1 - 36) as shown in Figure D.1.










                              D-30

                                T14N R23E

                 SEC 33  |        SEC 34         |  SEC 35
                         |                       |
                --------(A)---------(B)---------(C)--------
                         |                       |
                 SEC 4   |        SEC 3          |  SEC 2
                                T13N R23E

                                T13N R23E
                 SEC 33  |        SEC 34         |  SEC 35
                         |                       | 
                 -----+-(D)---------(E)-------+-(F)---- 3RD STD
PARALLEL NORTH
                     (X)                     (Y)
              SEC 4   |        SEC 3          |  SEC 2

                             T12N R23E


    Figure D.3 - Designations for East/West Boundary Corners.


                            Examples

         
----------------------------------------------------------------
                  TOWNSHIP  RANGE           SECTION         
LOCATION
         
----------------------------------------------------------------
             A    T13 14N  | R23E         | SECS 3 4 33 34  |
             B    T13 14N  | R23E         | SECS 3 34       | 1/4
COR
             C    T13 14N  | R23E         | SECS 2 3 34 35  |
            D    T13N     | R23E         | SECS 33 34      | SC
          or D    T13N     | R23E         | SEC 33          | SE
COR
             E    T13N     | R23E         | SEC 34          | 1/4
COR
             F    T13N     | R23E         | SECS 34 35      | SC
          or F    T13N     | R23E         | SEC 34          | SE
COR
             X    T12N     | R23E         | SECS 3 4        | CC
             Y    T12N     | R23E         | SECS 2 3        | CC
         
----------------------------------------------------------------













                              D-31
                   T17N R24E            |            T17N R25SE
                                  S 36  |  S 31       
 --- 4TH STD PARALLEL NORTH  ------+---(L)----        
                                  (Y)
                              S 1  |  S 6
                                --(K)-
                              S 12 |  S 7
                                --(J)-
              T16N R24E            |            T16N R25E
                          --------(I)--------
              T15N R24E            |            T15N R25E
                          --------(H)--------
              T14N R24E            |            T14N R25E
                          --------(G)--------
                              S 1  |  S 6
                                --(F)-
                              S 12 |  S 7
                                --(E)-
                              S 13 |  S 18
              T13N R24E         --(D)-          T13N R25E
                              S 24 |  S 19
                                --(C)-
                              S 25 |  S 30
                                --(B)-
                              S 36 |  S 31
 --- 3RD STD PARALLEL NORTH ---+--(A)--------
                              (X)
                          S 1  |  S 6
              T12N R24E      -(W)-              T12N R25E
                               |

   Figure D-4 - Designations for North/South Boundary Corners.

                            Examples

           
-----------------------------------------------------------
                    TOWNSHIP     RANGE       SECTION        
LOCATION
           
-----------------------------------------------------------
             W        T12N     | R24 25E  | SECS 1 6 7 12   |
             X        T12N     | R24 25E  | SECS 1 6        | CC
             A        T13N     | R24 25E  | SECS 31 36      | SC
             B        T13N     | R24 25E  | SECS 25 30 31 36|
             C        T13N     | R24 25E  | SECS 19 24 25 30|
             D        T13N     | R24 25E  | SECS 13 18 19 24|
             E        T13N     | R24 25E  | SECS 7 12 13 18 |
             F        T13N     | R24 25E  | SECS 1 6 7 12   |
             G        T13 14N  | R24 25E  | SECS 1 6 31 36  |
             H        T14 15N  | R24 25E  | SECS 1 6 31 36  |
             I        T15 16N  | R24 25E  | SECS 1 6 31 36  |
             J        T16N     | R24 25E  | SECS 7 12 13 18 |
             K        T16N     | R24 25E  | SECS 1 6 7 12   |
             Y        T16N     | R24 25E  | SECS 1 6        | CC
             L        T17N     | R24 25E  | SECS 31 36      | SC
           
-----------------------------------------------------------



                              D-32
 
                              ANNEX E

                 STATION ORDER-AND-TYPE (OT) CODES


This ANNEX contains lists of the various types of horizontal
control
points with the corresponding two-character Order-and-Type (OT)
Codes. 
These codes are used to classify every horizontal control point
according 
to the general order of accuracy of the main-scheme network of
which it is 
a part and according to the surveying method by which the point is

positioned.  The use of the OT Codes is explained in Chapter 2,
pages 2-35 
thru 2-38.

The first character (i.e., the "order code") of the OT Code
indicates the
order of accuracy of the main-scheme network of which the
horizontal
control point in question is a part or to which it is connected. 
It also
indicates whether the horizontal control point is permanently
marked and
recoverable (e.g., a monumented station or a landmark) or not
permanently
marked and hence nonrecoverable (e.g., an auxiliary point):

    ORDER CODES OF RECOVERABLE POINTS:
        A - Order A Interferometric Positioning
            B - Order B Interferometric Positioning
            0 - Trans-Continental Traverse (TCT)
        1 - lst-Order Survey Scheme
        2 - 2nd-Order (Class I and Class II) Survey Scheme
        3 - 3rd-Order (Class I and Class II) Survey Scheme
        4 - Lower-Than-3rd-Order Survey Scheme and Supplemental
              Unmonumented Recoverable Landmarks (see p. E-4)

    ORDER CODES OF NONRECOVERABLE POINTS:
        5 - lst-Order Survey Scheme
        6 - 2nd-Order (Class I and Class II) Survey Scheme
        7 - 3rd-Order (Class I and Class II) Survey Scheme
        8 - Lower-Than-3rd-Order Survey Scheme

The second code (i.e., the "type code") of the OT Code indicates
the
type of the (primary) surveying method by which the horizontal
control
point is positioned.  It also shows whether the horizontal control

point in question is a main-scheme station (i.e., one which is
essential
to the survey scheme) or a supplemental station (i.e., one which
is 
incidental to the survey scheme):

    TYPE CODES OF MAIN-SCHEME STATIONS:
        1 - Positioned Primarily by Triangulation (or by
        Intersection)
        2 - Positioned Primarily by Trilateration
            3 - Positioned Primarily by Traverse
            A - Positioned Primarily by Interferometric Satellite
            Relative             Positioning



                                E-1
    TYPE CODES OF SUPPLEMENTAL STATIONS:
        4 - Positioned Primarily by Triangulation
            5 - Positioned Primarily by Trilateration
            6 - Positioned Primarily by Traverse
            7 - Positioned by Intersection (Note: 1 if Main-Scheme
            Station)
            8 - Positioned by Resection
            B - Positioned Primarily by Interferometric Satellite
            Relative             Positioning


ORDER-AND-TYPE (OT) CODES OF RECOVERABLE HORIZONTAL CONTROL POINTS
- monumented (or otherwise permanently marked) stations, published
as indicated.

    SURVEY PROCEDURES            STATION TYPE         OT  PUBLISHE
                                                          D
        **************************   ************         **  ****
                                                              ****
                                                              *

MONUMENTED STATIONS POSITIONED BY GPS
    GPS Procedures               Main-Scheme      AA   AA-Order
    GPS Procedures               Main-Scheme      BA    B-Order
    GPS Procedures               Supplemental         BB    B-
                                                          Order

STATIONS OF THE TRANS-CONTINENTAL TRAVERSE (TCT)
    TCT Procedures               Main-Scheme *        03  lst-
                                                          Order
    TCT Procedures               Supplemental **  06  lst-Order

MONUMENTED STATIONS POSITIONED PRIMARILY BY TRIANGULATION
    lst-Order                    Main-Scheme      11  lst-Order
    lst-Order                    Supplemental         14  2nd-
                                                          Order
    2nd-Order (Class I or II)    Main-Scheme      21  2nd-Order
    2nd-Order (Class I or II)    Supplemental         24  3rd-
                                                          Order
    3rd-Order (Class I or II)    All Stations         31  3rd-
                                                          Order
    Lower-Than-3rd-Order         All Stations         41  Low-
                                                          Order

MONUMENTED STATIONS POSITIONED PRIMARILY BY TRILATERATION
    lst-Order                    Main-Scheme      12  lst-Order
    lst-Order                    Supplemental         15  2nd-
                                                          Order
    2nd-Order (Class I or II)    Main-Scheme      22  2nd-Order
    2nd-Order (Class I or II)    Supplemental         25  2nd-
                                                          Order
    3rd-Order (Class I or II)    All Stations         32  3rd-
                                                          Order
    Lower-Than-3rd-Order         All Stations         42  Low-
                                                          Order

MONUMENTED STATIONS POSITIONED PRIMARILY BY TRAVERSE
    lst-Order                    Main-Scheme      13  lst-Order
    lst-Order                    Supplemental         16  2nd-
                                                          Order
    2nd-Order (Class I or II)    Main-Scheme      23  2nd-Order
    2nd-Order (Class I or II)    Supplemental         26  2nd-
                                                          Order
    3rd-Order (Class I or II)    All Stations         33  3rd-
                                                          Order
    Lower-Than-3rd-Order         All Stations         43  Low-
                                                          Order

------------------------------------------------------------------
---------                        
   * Main-Scheme Station - one which is essential to the survey
scheme.     
  ** Supplemental Station - one which is incidental to the survey
scheme.    

                                E-2
    SURVEY PROCEDURES               STATION TYPE      OT 
PUBLISHED
    **************************      ************      ** 
*********      

MONUMENTED STATIONS POSITIONED BY INTERSECTION                 
    lst-Order                       Main-Scheme            11 
lst-Order
    lst-Order                       Supplemental      17  2nd-
Order
    2nd-Order (Class I or II)            Main-Scheme          21 
2nd-Order
    2nd-Order (Class I or II)            Supplemental         27 
3rd-Order
    3rd-Order (Class I or II)            All Stations         37 
3rd-Order
    Lower-Than-3rd-Order             All Stations         47  Low-
Order

                                                       
MONUMENTED STATIONS POSITIONED BY RESECTION
    lst-Order                       All Stations      18  2nd-
Order
    2nd-Order (Class I or II)            All Stations         28 
2nd-Order     
    3rd-Order (Class I or II)            All Stations         38 
3rd-Order
    Lower-Than-3rd-Order             All Stations         48  Low-
Order
                                                   
                                                       
ORDER-AND-TYPE (OT) CODES OF NONRECOVERABLE HORIZONTAL CONTROL
POINTS -temporary or auxiliary points, not permanently marked,
which must be carried in the files for network integrity purposes. 
These horizontal control points will not be published.

    SURVEY PROCEDURES               STATION TYPE      OT
    *************************           ************      **

STATIONS OF THE TRANS-CONTINENTAL TRAVERSE (TCT) - must be
monumented.

UNMARKED STATIONS POSITIONED PRIMARILY BY TRIANGULATION
    lst-Order                       Main-Scheme*      51
    lst-Order                        Supplemental**       54
    2nd-Order (Class I or II)            Main-Scheme           61
    2nd-Order (Class I or II)            Supplemental         64
    3rd-Order (Class I or II)            All Stations         71
    Lower-Than-3rd-Order             All Stations         81

UNMARKED STATIONS POSITIONED PRIMARILY BY TRILATERATION
    1st-Order                       Main-Scheme           52
    1st-Order                       Supplemental      55
    2nd-Order (Class I or II)            Main-Scheme          62
    2nd-Order (Class I or II)            Supplemental         65
    3rd-Order (Class I or II)            All Stations         72
    Lower-Than-3rd-Order             All Stations         82

------------------------------------------------------------------
------
  * Main-Scheme Station - one which is essential to the survey
scheme.     
 ** Supplemental Station - one which is incidental to the survey
scheme.    




                                 
                                E-3
    SURVEY PROCEDURES               STATION TYPE      OT  
    **************************      ************      **        

UNMARKED STATIONS POSITIONED PRIMARILY BY TRAVERSE
    1st-Order                       Main-Scheme       53          
    1st-Order                       Supplemental      56
    2nd-Order (Class I or II)            Main-Scheme          63
    2nd-Order (Class I or II)            Supplemental         66
    3rd-Order (Class I or II)            All Stations         73
    Lower-Than-3rd-Order             All Stations         83

UNMARKED STATIONS POSITIONED BY INTERSECTION
    lst-Order                       Main-Scheme           51
    lst-Order                       Supplemental      57
    2nd-Order (Class I or II)            Main-Scheme          61
    2nd-Order (Class I or II)            Supplemental         67
    3rd-Order (Class I or II)            All Stations         77
    Lower-Than-3rd-Order             All Stations         87

UNMARKED STATIONS POSITIONED BY RESECTION
    lst-Order                       All Stations      58
    2nd-Order (Class I or II)           All Stations      68
    3rd-Order (Class I or II)           All Stations      78
    Lower-Than-3rd-Order            All Stations      88
                                                               
                                                          
ORDER-AND-TYPE (OT) CODES OF UNMONUMENTED RECOVERABLE LANDMARKS -
normally
positioned as supplemental low-accuracy control points, possibly
used as   
main-scheme triangulation stations (e.g., a well-defined church
spire used
as the unoccupied center of a central-point figure in a
triangulation
network), published as indicated.

                                                       
    SURVEY PROCEDURES               STATION TYPE      OT 
PUBLISHED
    *************************           ************      ** 
*********

LANDMARKS USED AS MAIN-SCHEME TRIANGULATION STATIONS        
    lst-Order                       Main-Scheme           11  lst-
Order
    2nd-Order (Class I or II)           Main-Scheme           21 
2nd-Order    
    3rd-Order (Class I or II)           Main-Scheme           31 
3rd-Order
    Lower-Than-3rd-Order            Main-Scheme           41  Low-
Order

LANDMARKS POSITIONED AS SUPPLEMENTAL CONTROL POINTS
    Any-Order Traverse              Supplemental      43  Low-
Order
    Any-Order Intersection          Supplemental      47  Low-
Order
    Any-Order Resection             Supplemental      48  Low-
Order




                                                       


                                E-4

                              ANNEX F

                    NGS SURVEY EQUIPMENT CODES





          000-099 - Gravity Instruments and Satellite Systems
          100-199 - Theodolites and Transits
          200-299 - Leveling Instruments
          300-399 - Leveling Rods and Staffs
          400-499 - Steel and Invar Tapes
          500-599 - Lightwave Distance-Measuring Equipment
          600-699 - Infrared Distance-Measuring Equipment
          700-799 - Microwave Distance-Measuring Equipment
          800-899 - Total Station-Measuring Equipment
          900-999 - Other Miscellaneous Surveying Equipment





The purpose of the National Geodetic Survey (NGS) Survey Equipment
Code
is to provide a three-digit identifier for each item of survey
equipment
commonly used in connection with horizontal and vertical control
surveys
in the United States.  The code has been devised in such a manner
that
the first digit of the three-digit identifier would indicate a
specific
category of survey equipment.  Accordingly, there are ten broad
survey
equipment categories, the first of which (000-099) is reserved for
gravity instruments and satellite systems, and the last (900-999)
is 
reserved for miscellaneous survey equipment which does not fit
into any 
of the specific categories.  The ten survey equipment categories
are 
listed above.

Within each category, specific items and/or classes of survey
equipment
have been grouped into subcategories and assigned unique three-
digit
code numbers.  The grouping of survey equipment into subcategories
is
intended to reflect the level of accuracy attained in common usage
of
the specific items or classes of survey equipment in question and
not
necessarily their intrinsic or potential accuracy.  In each
category and
subcategory, a code is provided for items of survey equipment
which do not
appear among the items listed or which are not specifically
identified.
The respective lists of survey equipment are not all-inclusive,
and series
of numbers have been skipped in each category and/or subcategory
to allow
for additions.








                                                                   
                                                 F-1
CODE  MANUFACTURER            INSTRUMENT MODEL OR TYPE
****  ************            ************************  
                                                         
      000-099 - GRAVITY INSTRUMENTS AND SATELLITE SYSTEMS
      
                                                         
000       Unspecified               Unknown Instrument or System
                                                        
      001-009 - Reserved for Absolute Gravity Devices 
                                                         
      010-029 - Gravimeters                           
                                                         
010       Unspecified               Gravimeter             
                                                         
011       Frost                  Frost Gravimeter       
012       North American            North American Gravimeter
013       LaCoste-Romberg           Early Models           
014       LaCoste-Romberg           G-Meter                
015       LaCoste-Romberg           D-Meter                
016       Worden                    Unspecified            
017       Worden                    Uncompensated Model    
018       Worden                    Temperature-Compensated Model
019       Scintrex               CG-2                         
                                                         
      030-049 - Doppler Satellite Tracking Systems    
                                                         
030       Unspecified               Doppler Satellite Tracking
                                    System  

031       Magnavox               Geoceiver or Geoceiver II
032       JMR                       JMR-1
033       ITT                       ITT 5500
034       Magnavox               MX-702A
035       APL                       Tranet
036       Canadian Marconi          CMA 722A
037       Canadian Marconi          CMA 722B
038       Magnavox               MX-1502

      050-099 - GPS Satellite Tracking Systems        

050       Unspecified               GPS Satellite Tracking System

051       Western Atlas Intl.       MacrometerR V1000  
052       Western Atlas Intl.       MacrometerTM II
053       Texas Instruments, Inc.       TI-4100 (GESAR Software)
054       Texas Instruments, Inc.       TI-4100 (TI EPROM
                                        Software)
055       Trimble Navigation, Ltd.  4000 series
056       Leica-Wild-Magnavox       WM101/WM102/GPS-System 200
057       ISTAC, Inc.               Model 2002TM
058       EDO Canada, Ltd.          EDO JMR GeoTrak
059       Motorola, Inc.            Eagle series
060       Norstar Instruments, Ltd. Norstar 1000
061       SERCEL Inc.- USA          TR5S, NR101, NR104
062       Western Atlas Intl.       MINI-MACTM



                                F-2
CODE  MANUFACTURER            INSTRUMENT MODEL OR TYPE
****  ************            ************************

      050-099 - GPS Satellite Tracking Systems - Continued

063       Ashtech, Inc.             XII series
064       Allen Osborne Assoc., Inc.    Rogue series
065       NovAtel Commun., Ltd.     NovAtel GPSCardTM
066       Topcon America Corp.      GP-R1, GP-R1D
067       Del Norte Technology, Inc.    1008,1012
068       Magellan               NAV5000 PRO

      100-199 - THEODOLITES AND TRANSITS
      

100       Unspecified               Theodolite or Transit

      101-119 - Instruments of Geodetic Astronomy

101       Various                   Zenith Telescope
102       Various                   Meridian Telescope, Transit,
                                    or Circle
103       Various                   Bamberg-Type Astronomic
                                    Transit
104       Wild                   T-4
105       Kern                   DKM3-A
106       Gigas-Askania             TPR
107       Zeiss/Jena                Theo-Q02

      120-139 - First-Order (Geodetic) Theodolites

120       Unspecified               0."1, 0."2, 0."5 Direct-
                                    Reading Theodolite

121       Various                   Ramsden-Type 30, 24, 12-inch
                                    Theodolite
122       Various                   USC&GS Parkhurst
123       Wild                   T-3
124       Kern                   DKM3
125       CTS/Vickers               Geodetic Tavistock
126       Hilger-Watts           Microptic No. 3

      140-159 - Second-Order (Universal) Theodolites

140       Unspecified               1", 2", 5" Direct-Reading
                                    Theodolite

141       Various                   USC&GS 7-inch Repeating
                                    Theodolite
142       Wild                   T-2 or T-2E
143       Kern                   DKM2 or DKM2-A
144       CTS/Vickers               V-400 Series
145       Hilger-Watts           Microptic No. 2
146       Dietzgen/Askania          A2 or A2E
147       Zeiss/Oberkochen          Th2
148       Zeiss/Jena                Theo-010 or Theo-OlOA
149       Nikon                  NT-3 or NT-5
150       Sokkisha               TM-lA
151       Geotec                    TH-01



                                F-3
CODE  MANUFACTURER            INSTRUMENT MODEL OR TYPE
****  ************                ************************  

      160-169 - Third-Order (Construction) Theodolites

160     Unspecified                 Construction Theodolite or
Transit

161       Various                     10" Direct-Reading
                    Theodolite or Transit
162       Various                       20" Direct-Reading
                    Theodolite or Transit
163       Various                       30" Direct-Reading
                                    Theodolite or Transit
164       Various                        1' Direct-Reading
                                        Theodolite or Transit

      170-179 - 30' or Coarser Angulation Devices

170     Unspecified                30' or Coarser Angulation
                       Device

171       Various                       30' or Coarser Theodolite
or Transit
172       Various                      30' or Coarser Compass
Device
173       Various                      30' or Coarser Protractor

      180-199 - Gyroscopic Theodolites

180       Unspecified                  Gyro-Theodolite
                                                                  
             200-299 - LEVELING INSTRUMENTS
         
                                              
200     Unspecified               Leveling Instrument

       210-249 - Precise (Geodetic) Levels                 
 
210       Unspecified                Precise Level
      
      211-230 - Precise Spirit (Bubble-Vial) Levels           
 
211       Various                      USC&GS Fischer
212     USC&GS                     Stampfer-Type (1877-1899)
213     Buff & Berger               Van Orden or Mendenhall
214       Various                      Kern-Type (US Engineers)
215       Zeiss                  Ni-III or Ni-A
216       Zeiss/Jena                Ni-004
217       Wild                   N-3
218       Kern                   NK3-M
219       Breithaupt                NABON
220       Fennel                    Precise Level
221       Hilger-Watts           Precise Level
222       CTS/Vickers               Geodetic Level                
                                      
223       Sokkisha               PL-5
224       Keuffel & Esser           Precise Level







                                F-4
CODE  MANUFACTURER            INSTRUMENT MODEL OR TYPE
****  ************            ************************

      231-249 - Precise Compensator (Self-Aligning) Levels

231       Zeiss/Oberkochen          Nil
232       Zeiss/Oberkochen          Ni2    
233       Zeiss/Jena                Ni-002
234       Zeiss/Jena                Ni-007
235       Wild                   NA-2 or NAK-2
236       Salmoiraghi               5190
237       MOM                       Ni-A31
238       Sokkisha               B-1
239       Kern                   GK2-A
240       Topcon                    AT-D2
241       Zeiss                  Ni-005A
242       Leica/Wild                NA2000 or NA2002 Digital Level
243       Leica/Wild                NA3000 Digital Level

        250-289 - Engineer's (Universal) Levels

250        Unspecified             Engineer's Level            
      
      251-270 - Engineer's Spirit (Bubble-Vial) Levels

251       Various                18-inch Dumpy-Type Level
252       Various                18-inch Wye-Type Level
253       Zeiss               Ni-II or Ni-B
254       Zeiss/Jena             Ni-030
255       Wild                N-2 or NK-2
256       Kern                NK3
257       Kern                NK2
258       Kern                GK23
259       Breithaupt             NAKRE
260       Fennel                 Engineer's Level
261       Hilger-Watts        Engineer's Level
262       CTS/Vickers            Engineer's Level
263       Salmoiraghi            5160 Series
264       Nikon               S2
265       Sokkisha            TTL-5 or TTL-6
266       Geotec                 L-11 or L-21

      271-289 - Engineer's Compensator (Self-Aligning) Levels

271       Zeiss/Oberkochen       Ni22
272       Zeiss/Jena             Ni-025
273       Kern                GKl-A
274       Breithaupt             AUTOM or AUCIR
275       Fennel                 AUING
276       Hilger-Watts        AUTOSET
277       Salmoiraghi            5173, 5175, or 5180
278       Ertel               INA
279       Nikon               AE Series
280       Sokkisha            B-2
281       Geotec                 AL-2 or AL-23
282       Sokkisha            C-1

                                F-5
CODE  MANUFACTURER        INSTRUMENT MODEL OR TYPE
****  ************        ************************

      290-299 - Builder's (Construction) Levels

290       Unspecified            Builder's Level

291       Various                Builder's Dumpy-Type Spirit Level
292       Various                Builder's Tilting Spirit Level
293       Various                Builder's Compensator Level

      300-399 - LEVELING RODS AND STAFFS
      
                                   
300       Unspecified            Leveling Rod or Staff

      310-349 - Precise (Geodetic) Metal-Scale Rods
                                    
310       Unspecified         Precise Metal-Scale Rod

311       USC&GS              USC&GS Pre-Invar Rods
312       USC&GS              Invar (Introduced in 1916)         
313       Zeiss/Oberkochen    Invar
314       Zeiss/Jena          Invar
315       Wild            Invar
316       Kern            Invar
317       Breithaupt          Invar
318       Fennel              Invar
319       Hilger-Watts    Invar
320       CTS/Vickers         Nilex
321       Salmoiraghi         Invar
322       Keuffel & Esser     Invar
323       Gurley              Invar
324       Renick              Invar (checkerboard)
325       USGS                Invar (Metal-Frame)
340       Nedo            Invar
341       Nestler             Invar

      350-389 - Engineer's Wooden Rods and Staffs

350       Unspecified         Engineer's Wooden Rod or Staff

351       Various             US Engineers 12-foot Rigid Rod
352       Various             US Geological Survey 12-foot Rigid
                              Rod

      390-399 - Builder's Rods and Staffs
                                       
390       Unspecified         Builder's Rod or Staff

391       Various             Philadelphia Rod
392       Various             Chicago Rod
393       Various             California Rod
394       Various             12-foot Folding Rod
395       Leica/Wild          3-piece Fiberglass (Bar-Code) Rod
396       Leica/Wild          Invar (Bar-Code) Rod      
                                       
                                F-6
CODE  MANUFACTURER        INSTRUMENT MODEL OR TYPE
****  ************        ************************

      400-499 - STEEL AND INVAR TAPES
      

400       Unspecified            Steel or Invar Tape

      420-439 - Calibrated Invar Tapes

420       Unspecified            Calibrated Invar Tape
421       Various                25-meter Calibrated Invar Tape
422       Various                50-meter Calibrated Invar Tape
423     Various                 100-foot Calibrated Invar Tape

      440-459 - Calibrated Steel Tapes

440       Unspecified            Calibrated Steel Tape

441       Various                30-meter Calibrated Steel Tape
442       Various                100-foot Calibrated Steel Tape
443       Various                300-foot Calibrated Steel Tape

      460-479 - Uncalibrated Steel Tapes

460       Unspecified            Uncalibrated Steel Tape or Ruler

461       Various                30-meter Uncalibrated Steel Tape
462       Various                100-foot Uncalibrated Steel Tape
463       Various                300-foot Uncalibrated Steel Tape

      500-599 - LIGHTWAVE DISTANCE-MEASURING EQUIPMENT
      

500       Unspecified            Lightwave Electro-Optical DME

501       AGA                    Geodimeter Model 1
502       AGA                    Geodimeter Model 2 or 2A
503       AGA                    Geodimeter Model 3
504       AGA                    Geodimeter Model 4A, 4B, or 4D
505       AGA                    Geodimeter Model 4L or 4L 10A
506       AGA                    Geodimeter Model 6
507       AGA                    Geodimeter Model 6A
508       AGA                    Geodimeter Model 6B
509       AGA                    Geodimeter Model 6BL
510       AGA                    Geodimeter Model 7T
511       AGA                    Geodimeter Model 700 or 710
512       AGA                    Geodimeter Model 76 or 78
513       AGA                    Geodimeter Model 8
531       Keuffel & Esser        LSE Ranger I, II, or III
532       Keuffel & Esser        LSE Ranger IV
533       Keuffel & Esser        LSE Ranger V
534       Keuffel & Esser        LSE Rangemaster
535       Keuffel & Esser        Rangemaster II
536       Keuffel & Esser        Uniranger
      
                                F-7
CODE  MANUFACTURER        INSTRUMENT MODEL OR TYPE
****  ************        ************************

      500-599 - LIGHTWAVE DISTANCE-MEASURING EQUIPMENT - CONTINUED
      


541       Spectra-Physics        Geodolite 3G
542       Spectra-Physics        Transitlite LT-3
551       Kern                ME-3000 Mekometer
561       Cubic Percision        Rangemaster III
562       Cubic Percision        Ranger V-A
571       Leitz               Red 2L

      600-699 - INFRARED DISTANCE-MEASURING EQUIPMENT
      

600       Unspecified            Infrared Electro-Optical DME

601       AGA                    Geodimeter Model 12 or 12A
602       AGA                    Geodimeter Model 78,110,114,116
603       AGA                    Geodimeter Model 210 or 220
604       AGA                    Geodimeter Model 120 or 216
605       AGA                    Geodimeter Model 6000
606       AGA                    Geodimeter Model 14 or 14A
607       AGA                    Geodimeter Model 112 or 122
611       Plessey                Tellurometer CD-6
612       Plessey                Tellurometer MA-100
613       Plessey                Tellurometer MA-200
616       Lietz               Red Mini 2
617       Lietz               Red 2A
621       Wild                Distomat DI-3 Series
622       Wild                Distomat DI-10 Series
623       Wild                Distomat DI-4L
624       Wild                Distomat DI-5 or DI-5S              
625       Wild                DI 1000 or 1000L
626       Wild                DI 2000
627       Wild                DI 3000 (time-pulse)
628       Leica/Wild             DI 2002
629       Leica/Wild             DI 1600
631       Kern                DM-500
632       Kern                DM-1000 or DM-2000
633       Kern                DM 104 or DM 150
634       Kern                DM 503 or DM 550
635       Kern                DM 504
641       Zeiss/Oberkochen       SM 11 or RegElta 14
642       Zeiss/Oberkochen       Eldi Series
643       Zeiss/Oberkochen       SM 4
651       Keuffel & Esser        LSE Microranger or Microranger II
652       Keuffel & Esser        LSE Autoranger
661       Hewlett-Packard        3800A or 3800B
662       Hewlett-Packard        3805 or 3810
663       Hewlett-Packard        3808A
667       Pentax                 MD-14 or MD-20
671       Cubic Precision        Cubitape DM-60
672       Cubic Precision        HDM-70

                                F-8
CODE  MANUFACTURER        INSTRUMENT MODEL OR TYPE
****  ************        ************************  

      600-699 - INFRARED DISTANCE-MEASURING EQUIPMENT - CONTINUED
      

673       Cubic Precision        DM-80 or DM-81
674       Cubic Precision        AutoRanger II
675       Cubic Precision        Beetle 500 or 500S
676       Cubic Precision        Beetle 1000 or l000S
681       Carrol & Reed          Akkuranger Mark I
685       Topcon                 DM-C2
686       Topcon                 DM-A2 or DM-A3
687       Topcon                 DM-S2 or DM-S3
688       Topcon                 GTS-2R
693       Nikon               ND 20 or ND 21 or ND 26
694       Nikon               ND 30 or ND 31

      700-799 - MICROWAVE DISTANCE-MEASURING EQUIPMENT
      

700       Unspecified            Microwave Electro-Magnetic DME

701       Plessey                Tellurometer MRA-1
702       Plessey                Tellurometer MRA-2
703       Plessey                Tellurometer MRA-3
704       Plessey                Tellurometer MRA-4
705       Plessey                Tellurometer MRA-5
709       Plessey                Tellurometer CA-1000
731       Wild                Distomat DI-50
732       Wild                Distomat DI-60
741       Cubic               Electrotape DM-20
751       Fairchild           Microchain

      800-899 - TOTAL STATION-MEASURING EQUIPMENT
      

800       Unspecified            Total Station

      801-860 - Self Contained Instruments

801       Leitz               SDM3F or SDM3FR
802       Leitz               SET 2
803       Leitz               SET 3
804       Leitz               SET 4
810       Nikon               NTD-4
811       Nikon               NTD-2S
812       Nikon               DTM1
813       Nikon               DTM5
816       Geotronics AB          Geodimeter 142
817       AGA                    Geodimeter 140
821       Pentax                 PX20D
822       Pentax                 PX10D
823       Pentax                 PX06D            
824       Pentax                 PTS-10              

                                F-9
CODE  MANUFACTURER        INSTRUMENT MODEL OR TYPE
****  ************        ************************

      801-860 - Self Contained Instruments - Continued

825       Pentax                 PTS-1110            
826       Pentax                 PTS-1105            
830       Topcon                 GTS or GTS-2R              
831       Topcon                 GTS-3B or GTS-3C
832       Topcon                 ET-1 or ET-2
833       Topcon                 GTS-4A or GTS-4B
840       Wild                TC1600
841       Wild                TC2000
842       Leica/Wild             TC2002
850       Zeiss               ELTA 3              
851       Zeiss               ELTA 4
856       Hewlett-Packard        3820A

      861-899 - Modular Instruments

861       Kern                E1/DM504
862       Kern                E2/DM504
871       Leitz               DT2/Red Mini 2
872       Leitz               DT2/Red 2A or Red 2L
881       Wild                T1000
882       Wild                T1600
883       Wild                T2000 or T2000S
884       Wild                T2002
885       Leica/Wild             T3000

      900-999 - OTHER MISCELLANEOUS SURVEYING EQUIPMENT
      

900       Unspecified            Miscellaneous Surveying
                          Equipment





















                               F-10
                              ANNEX G

            ELLIPSOID HEIGHT ORDER-AND-CLASS (OC) CODES


This annex contains ellipsoid height Order and Class (OC) codes. 
These two-digit codes are used to classify each ellipsoid height
value observed and adjusted at horizontal control points.

The first character of the OC code indicates the order and the
second character the class, in accordance with the following draft
standards for classifying ellipsoid height determinations:

                                      b = Maximum Height
OC Code      Classification           Difference Accuracy

  11       First Order, Class I               0.5
  12       First Order, Class II              0.7
  21       Second Order, Class I              1.0
  22       Second Order, Class II             1.3
  31       Third Order, Class I               2.0
  32       Third Order, Class II              3.0
  41       Fourth Order, Class I              6.0
  42       Fourth Order, Class II            15.0
  51       Fifth Order, Class I              30.0
  52       Fifth Order, Class II             60.0

The ellipsoid height difference accuracy (b) is computed from a
minimally constrained, correctly weighted, least squares
adjustment by the formula:

                          b = s / sqrt(d)

where:  d = horizontal distance in kilometers between control
points.
        s = propagated standard deviation of ellipsoid height
difference
            in millimeters between control points obtained from
the least
            squares adjustment.

The following table lists the standard errors of ellipsoid height
differences at various distances:

                            Standard Error (mm)

                               OC Code

Distance (km)   11   12   21   22   31   32   41   42   51   52

     1          .5   .7  1.0  1.3    2    3    6   15   30   60
     5         1.1  1.6  2.2  2.9  4.5  6.7   13   34   67  134
    10         1.6  2.2  3.2  4.1  6.3  9.5   19   47   95  190
    25         2.5  3.5  5.0  6.5   10   15   30   75  150  300
    50         3.5  4.9  7.1  9.2   14   21   42  106  212  424
    75         4.3  6.1  8.7   11   17   26   52  130  260  520
   100         5.0  7.0   10   13   20   30   60  150  300  600

                                G-1



















                       INTENTIONALLY BLANK

































                               G-2

                               ANNEX I

     SUMMARY OF CODES USED IN GEODETIC SURVEY POINT DESCRIPTIONS

This annex contains lists of codes that are used in the preparation
of station descriptions and recovery notes pertaining to geodetic
control points.  The use of these codes is explained in Chapter 3,
entitled GEODETIC SURVEY POINT DESCRIPTIVE (GEOD DESC) DATA.


DR CODE - used to identify the descriptive data by type.

   ENTRY         DEFINITION
     D      An original description of a newly set mark.

    R       Everything else (includes recovered, not recovered,
        destroyed, andthe first report to NGS of a pre-existing
                 mark not in the NGS data base).  


RECOVERY TYPE CODE (optional) - used to classify recovery
descriptions relative to existing information residing in the agency
data base.

   ENTRY         DEFINITION

    F       A full recovery description of a survey point which you
            think is not included in the NGS Data Base.

    M       A recovery description which does not contain a
            complete textual description of the mark, but may
            contain updates or modifications to the most current
            description.  This is used when a mark is destroyed or
            not recovered, or when the text of the previous
            description of this mark in the NGS data base requires
            no update (i.e., the text is in accord with current
            practice, and the situation at the mark has not
            changed).  

    T       A complete re-description of a mark which is included
            in the NGS data base.


SPECIAL APPLICATIONS CODE - used to represent certain specialized
information about the control point.

   ENTRY         DEFINITION

    F       Fault monitoring site

    N       Site not suitable for receiving satellite signals

    O       Other (see descriptive text)

    P       Site determined suitable for receiving satellite
            signals in connection with geodetic surveys

    T       Tidal station

                                 I-1
SETTING CODE - used to complement all MARKER TYPE CODES except
Landmark
               stations.
                                               
    SHALLOW SETTINGS (LESS THAN 10 FT DEEP)               DEFAULT
                                                          STABILITY
                                                          CODE

     00 - setting not listed - see description                     D
     01 - unspecified shallow                                      D
     02 - driven into the ground                                   D
     03 - imbedded in the ground                                   D
     04 - surrounded by a mass of concrete                         D
     05 - set into the top of an irregular mass of concrete        D
     07 - set into the top of a round concrete monument            C
     08 - set into the top of a square concrete monument           C
          set into the top of a prefabricated concrete post ...
     09 - ... imbedded in the ground                               D
     10 - ... surrounded by a mass of concrete                     D
     11 - ... imbedded in a mass of concrete                       C
          set into a prefabricated concrete block ...
     12 - ... imbedded in the ground                               D
     13 - ... surrounded by a mass of concrete                     D
     14 - ... imbedded in a mass of concrete                       C
     15 - a metal rod driven into the ground                       D
     16 - a metal rod with base plate buried/screwed into the ground
    C
          set into the top of a metal pipe ...
     17 - ... driven into the ground                          D
     18 - ... imbedded in the ground                               D
     19 - ... surrounded by a mass of concrete                     D
     20 - ... imbedded in a mass of concrete                       C
          set in concrete at the center of a clay tile pipe ...
     21 - ... fastened to a wooden pile driven into marsh          D
     22 - ... imbedded in the ground                               D
     23 - ... surrounded by a mass of concrete                     D
     24 - ... imbedded in a mass of concrete                       C

     SETTINGS IN STRUCTURES

     30 - light structures (other than listed below)               D
     31 - pavements (street, sidewalk, curb, apron, etc.)          D
     32 - retaining walls, etc.= concrete ledge                    C
     33 - piles and poles (e.g. spike in utility pole)             D
     34 - footings/foundation walls of small/medium structures     C
     35 - mat foundations, etc. = concrete slab                    C
     36 - massive structures (other than listed below)             B
     37 - massive retaining walls                                  B
     38 - abutments and piers of large bridges                     B
     39 - tunnels                                                  B
     40 - massive structures with deep foundations                 A
     41 - large structures with foundations on bedrock             A

     UNSLEEVED DEEP SETTINGS (10 FT. + )

     45 - unspecified depth                                        C
     46 - copper-clad steel rod                                    B
     47 - galvanized steel pipe                                    B
     48 - galvanized steel rod                                     B
     49 - stainless steel rod                                      B
     50 - aluminum alloy rod                                       B

                                 I-2

    SLEEVED DEEP SETTINGS  (10 FT. +)                     DEFAULT
                                                          STABILITY
                                                          CODE

     55 - unspecified pipe/rod in sleeve                           B
     56 - copper-clad steel rod in sleeve                          B
     57 - galvanized steel pipe in sleeve                          A
     58 - galvanized steel rod in sleeve                           A
     59 - stainless steel rod in sleeve                            A
     60 - aluminum alloy rod in sleeve                             A

     SETTINGS IN ROCKS OR BOULDERS

     65 - unspecified rock                                         B
     66 - in rock outcrop                                          A
     67 - set into a drill hole in rock outcrop                    A
     68 - ... and marked by a chiseled cross                       A
     69 - ... and marked by a chiseled triangle                    A
     70 - ... and marked by a chiseled circle                      A
     71 - ... and marked by a chiseled square                      A
     73 - in a rock ledge                                      A
     74 - set into a drill hole in a rock ledge                A
     75 - ... at the intersection of two chiseled lines        A
     76 - ... and marked by a chiseled triangle                A
     77 - ... and marked by a chiseled circle                  A
     78 - ... and marked by a chiseled square                  A
     80 - in a boulder                                         C
     81 - set into a drill hole in a boulder                   C
     82 - ... and marked by a chiseled cross                   C
     83 - ... and marked by a chiseled triangle                C
     84 - ... and marked by a chiseled circle                  C
     85 - ... and marked by a chiseled square                  C
     87 - in a partially exposed boulder                       C
     88 - set into a drill hole in a partially exposed boulder C
     89 - ... and marked by a chiseled cross                   C
     90 - ... and marked by a chiseled triangle                C
     91 - ... and marked by a chiseled circle                  C
     92 - ... and marked by a chiseled square                  C
     93 - in bedrock                                           A
     94 - set in a drill hole in bedrock                       A
          set into a mass of concrete ...
     95 - ... in a depression in rock outcrop                  A
     96 - ... in a depression in a rock ledge                  A
     97 - ... in a depression in a boulder                     C
     98 - ... in a depression in a partially exposed boulder   C
     99 - ... in a depression in the bedrock                   A











                                 I-3

MARKER TYPE CODES - (Not for Landmark stations)


    A - aluminum marker (other than a disk)       E - earthenware
                                                  pot

    B - bolt                                  F - flange-encased rod

    C - cap-and-bolt pair                     G - glass bottle

    DA - astro pier                       H - drill hole

    DB - bench mark disk                      I - metal rod

    DD - survey disk                          J - earthenware jug

    DE - traverse station disk                K - clay tile pipe

    DG - gravity station disk                 L - gravity plug

    DH - horizontal control disk              M - ammo shell casing

    DJ - tidal station disk                   N - nail

    DK - gravity reference mark disk          O - chiseled circle

    DM - magnetic station disk                P - pipe cap

    DO - unspecified disk type (see text)         Q - chiseled
                                                  square

    DP - base line pier disk                  R - rivet

    DQ - calibration base line disk           S - spike

    DR - reference mark disk                  T - chiseled triangle
             
    DS - triangulation station disk           U - concrete post
                            
    DT - topographic station disk                 V - stone monument

    DU - boundary marker disk                 W - unmonumented

    DV - vertical control disk                X - chiseled cross

    DW - NOS hydrographic survey disk             Y - drill hole in
                                                  brick

    DZ - azimuth mark disk                    Z - see description









                                 I-4

MARKER TYPE CODES (Landmark stations)


     Landmarks                    Tanks and Towers:
     Not Listed:

     00 - see description         51 - tank
                                  52 - standpipe tank
     Natural Objects:             53 - elevated tank
                                  54 - water tower
     01 - lone tree               55 - tower
     02 - conspicuous rock        56 - skeleton tower
     03 - mountain peak           57 - lookout tower
     04 - rock pinnacle           58 - control tower
     05 - rock awash

     Waterfront Landmarks         Miscellaneous
     and Visual Aids              Landmarks:
     to Navigation:
                                  61 - pole
     11 - piling                  62 - flagpole
     12 - dolphin                 63 - stack
     13 - lighthouse              64 - silo
     14 - navigation light        65 - grain elevator
     15 - range marker            66 - windmill
     16 - daybeacon               67 - oil derrick
     17 - flag tower              68 - commercial sign
     18 - signal mast             69 - regulatory sign
                                  70 - monument
     Aeronautical and             71 - boundary monument
     Electronic Aids              72 - cairn
     to Navigation:               73 - lookout house
                                  74 - large cross
     21 - airport beacon          75 - belfry
     22 - airway beacon
     23 - VOR antenna             Features of
     24 - RBN antenna             a Building:
     25 - radar antenna
     26 - spherical radome        81 - gable
     27 - radio range mast        82 - finial
     28 - LORAN mast              83 - flagstaff
                                  84 - lightning rod
     Broadcast and                85 - chimney      
     Communications               86 - cupola
     Facilities:                  87 - dome
                                  88 - observatory dome
     41 - antenna mast            89 - spire
     42 - radio/TV mast           90 - church spire
     43 - radio/TV tower          91 - church cross
     44 - microwave mast          92 - antenna
     45 - microwave tower         93 - microwave antenna
                                  94 - rooftop ventilator
                                  95 - rooftop blockhouse 


                                 I-5

MAGNETIC CODE - used to indicate the magnetic property of the mark
or monument.

    A - steel rod adjacent to monument
    B - bar magnet imbedded in monument
    H - bar magnet set in drill hole
    I - marker is a steel rod
    M - marker equipped with bar magnet
    N - no magnetic material
    O - other - see description
    P - marker is a steel pipe
    R - steel rod imbedded in monument
    S - steel spike imbedded in monument
    T - steel spike adjacent to monument

TRANSPORTATION CODE - used to indicate the mode of transportation
used (or to be used) to reach the station or to reach the location
where packing begins, if packing to the station site is required.

    A - light airplane
    B - boat
    C - car (or station wagon)
    F - float airplane
    H - helicopter
    O - other (see descriptive text)
    P - light truck (pickup, carryall, etc.)
    T - truck (larger than 3/4 ton)
    W - tracked vehicle (Weasel, Snowcat, etc.)
    X - four-wheel drive vehicle

AGENCY CODE - used to indicate the type of survey organization which
established or recovered the geodetic control point.

    A - National Agencies
    B - Inter-State or Inter-Province Agencies
    C - State, Province, Commonwealth, and Territorial Agencies
    D - County Agencies
    E - Municipal Agencies (Cities)
    F - Inter-City and Inter-County Agencies
    G - Railroads
    H - Utility and Natural Resource Companies
    I - Surveying, Engineering, and Construction Industry
    J - Educational Institutions
    K - Professional and Amateur Associations
    L - Miscellaneous Commercial or Private Firms
    M - Non-Specific Designators

CONDITION CODE - used to indicate the condition of the monument or
mark each time the geodetic control point is recovered.

    G - Good
    N - Not Recovered, Not Found
    P - Poor, Disturbed, Mutilated, Requires Maintenance
    X - Destroyed (See Note Below)


                                 I-6

STABILITY CODE - may be entered in the *26* coded record to override
the software default codes in the descriptions for publication.

    CODE         DEFINITION

    A       Monuments of the most reliable nature, expected to hold
            their elevations very well.

    B       Monuments which generally hold their elevations fairly
            well.

    C       Monuments which may be affected by surface ground
            movements.

    D       Monuments of questionable or unknown vertical
            stability.  
      









































                                 I-7



















                         INTENTIONALLY BLANK

































                                 I-8

                              ANNEX K

                    PROJECT REPORT INSTRUCTIONS


Information concerning data preparation and transmittal to NGS is
found in Chapter 1, HORIZONTAL CONTROL (HZTL) DATA, in Chapter 5,
VERTICAL CONTROL (VERT) DATA, and in Chapter 9, GRAVITY CONTROL
(GRAV) DATA.  The section titled "Media for Submitting Data"
describes procedures for packaging of the data as well as
information required in the letter of transmittal pertaining to
the floppy disks or magnetic tape.  The transmittal letter should
inventory the total contents of the shipment.  In addition,
special instructions for submitting GPS relative positioning data
to the NGS are provided in ANNEX L.

The most important supporting document that should be included
with the shipment is the project report.  The project report is
the permanent hardcopy record that summarizes project
accomplishments.  It describes the general project goals and the
equipment and procedures employed to meet specific conditions and
requirements.  The report provides information useful for
verification and adjustment, including detailed explanation of
unusual or special features of the project.  The recommended
content of a project report follows.  The project sketch is an
attachment to the report.  For projects totally or partially
supported by NGS, a different report may be required.


          Report Outline for a Horizontal Control Project

   I. Title page.  List the type of report (Horizontal Control),
order-class         of survey, project title including the state,
any appropriate                  identifying control number,
beginning and ending dates of field work,         agency name, and
the name of the project director (supervisor).  The         
project title should include the locality of the survey (e.g.,
Brainerd     to Crosby, MN).

   II.    The report should address the following topics:

      A.  Location.  Briefly describe the project area, indicating
each            state and the counties in which the project is
located.

      B.  Scope

          1. Purpose.  State the purpose of the survey and the
extent to                 which the requirements were satisfied.

          2. Specifications.  State the specifications which were
followed               and the methods used.

          3. Monumentation.  Describe the monumentation that was  
                    established and recovered.






                                 K-1
          4. Instrumentation.  List the instruments and equipment
used.                     For EDM, describe the instrument
calibration and how the                    calibration and
refractive index corrections were applied.                  
Include model and serial numbers of all instrumentation.     
                                
          5. Special equipment.  List any special equipment used. 
                       Examples include Bilby towers, helicopters,
wooden stands,                   Peck towers, etc.

          6. Existing control.  List all existing horizontal
control             contained in the project area, NGS-published
or otherwise.                 For NGS control, list the quadrangle
and station numbers.                    Also, include any bench
marks used to control the elevations.                For existing
horizontal control not connected to the new                    
survey, include an explanation of why connections were not        
          made.

      C.  Comments   (THIS IS THE MOST IMPORTANT SECTION OF THE
REPORT!)

          1. Reconnaissance.  When a reconnaissance plan was
submitted and                 approved by NGS prior to beginning
the field measurements,                    describe any changes
from the original reconnaissance and the                reasons
for the changes.

          2. Specifications.  Describe any deviations from the
specifica-             tions used and the reason for such
deviations.

          3. Computations.  Describe which computations were
performed,                    the coordinate system used (e.g.,
latitude and longitude,                    state plane, or local
rectangular grid), and what type of                     
adjustment, if any, was performed.

          4. Problems.  Describe any problems encountered such as: 
moved                  or "suspect" marks, bad check angles, and
poor position,                   azimuth, and length checks.       
                            

          5. Recommendations.  Describe any recommendations for
future                    field measurements and/or recomputation
of published data.
                             
      D.  Statistics 

          1. Points.  List the number of points positioned grouped
by type                of mark such as:  new main scheme, old main
scheme, and/or                   landmark stations.

          2. Observations.  List the number of observations and
their               precision grouped by type of observation such
as:  horizontal                  directions, zenith distances,
vertical angles, distances, and               astronomic azimuths.



                                 



                                K-2
          3. Closures 

             a.  Triangle.  List the number of triangles, the
average                         triangle closure, and the maximum
triangle closure.  For                      the maximum triangle
closure, identify the three                          vertices.

             b.  Traverse.  For each traverse closure, identify
the                           traverse segment and list the
azimuth closure, the                          position closure,
the total length, the number of                         courses,
and the minimum course length.

          4. Reoccupations.  List any reoccupied stations, the
lines               reobserved, the reason for the remeasurement.

          5. Check measurements.  List comparisons between
previously             observed angles (check angles) and/or
distances with current                  observations.  Also, list
the average and maximum                           disagreements.

          6. Fixed measurements.  List comparisons between
computed            observations (computed from existing
coordinate data) and             current observations.  Also, list
the average and maximum             disagreements.

      E.  Status

          1. Records.  Describe the current status and future
disposition               of the station and observation records. 
If submitted to NGS,                they will be archived in a
Federal records center.

          2. Contact.  Provide the name and telephone number of a
person                 to contact regarding questions which may
arise during NGS                    processing of the data.

   III.   Attachment to the report.  Include as an attachment to
the project            report an original and three copies of a
sketch of the project area.         The sketch must show station
names and lines which were observed for
          angles and distances.  To ensure that reproductions and
film re-
            ductions of sketches are of optimum quality, sketches
should not be             drawn on maps.  Although linen, mylar or
vellum are desirable, it is         not required.  A 24" x 36"
sketch is preferred, but the size should          not exceed 36" x
48".  An overview of the project geometry is one            
objective of the sketch, and, therefore, a scaled drawing with
tick         marks is required.  Symbols and notations explained
in C&GS Special           Publication 247, (1959: pp. 6,191, and
192) are suggested.  The         names of main scheme stations
will be placed adjacent to the station        symbol. 
Supplemental stations may be numbered for reference to a          
   list of names.  Submitting agency or organization name should
appear          in a title block.  The sketch may be handlettered.






                                K-3

           Report Outline for a Vertical Control Project

   I. Title page.  List the type of report (Vertical Control),
order and              class of survey, project title including
the state, any appropriate          identifying number (for
projects that have been assigned HGZ accession          numbers by
NGS, the numbers should be listed on the title page),             
beginning and ending dates of both mark setting and leveling,
agency          name, and the name of the project director
(supervisor).  The project          title should include the
locality of the project.

   II.    The report should address the following topics:

      A.  Location.  Briefly describe the project area, including
state                  or states in which it is located.  Note the
number of lines, their              general configuration, and
their total distance.

      B.  Scope

          1.  Purpose.  State the purpose of the survey and the
extent to                 which the requirements were satisfied.

          2.  Specifications.  State the specifications which were
followed                and the methods used.

          3. Monumentation.  Describe the monumentation that was  
                       established and recovered.

          4. Instrumentation.  Describe the equipment, including a
list of                instruments, rods (including calibration
information), and                   recording equipment.  Include
model and serial numbers of all               equipment and the
dates they were in use.  Note the reasons               for return
of equipment for repairs or adjustment.  For rod               
calibrations, cite which previously submitted calibration data    
             are to be used to process the project.  If none were
submitted                 previously, include such calibration
data with the leveling                  data submitted with this
report.

      C.  Comments  (THIS IS THE MOST IMPORTANT SECTION OF THE
REPORT!)

          1. Reconnaissance.  If a reconnaissance plan was
submitted and                 approved by NGS prior to beginning
the field measurements,                    describe any changes
from the original reconnaissance and the                reasons
for the changes.

          2. Specifications.  Describe any deviations from the
             specifications used and the reason for such
deviations.









                                K-4
          3.  Routes.  Briefly describe each line, including line
number or                 other identification, topography and
climate, features of the                routing such as control
point spacing and frequency of                       connections,
unusual points leveled, unusual procedures, river
             or valley crossings, and ties established.

          4. Problems.  Describe all problems encountered, such
as:  moved                or "suspect" marks, systematic new-
minus-old comparisons, poor                ground or atmospheric
conditions, etc.

          5. Recommendations.  Mention specific sections that
required                      additional work as a result of
preliminary analysis.  Describe               areas which may
require additional leveling in the future.

      D.  1. Closures.  List loop closures for all loops of
concurrent                    surveys.  State the accumulated
forward-backward difference                for each line.

          2. Check-measurements.  Compute and list new-minus-old   
                       tabulations for all releveling of
previously leveled lines.                  Also, list the average
and maximum disagreements.

          3. Progress. (Needed only if submitting organization is  
                       supported by NGS funding and/or equipment). 
Total progress                   along lines, double-run progress,
single-run progress, total                 distance leveled,
distance leveled as reruns, and number of     
             sections.

          4.  Reruns.  For all sections that were releveled for
any reason             other than those exceeding the tolerance
limit, list the
             sections and the reasons for releveling.

      E.  Status

          1. Records.  Describe the current status and future
disposition                   of the station and observation
records.  If submitted to NGS,             they will be archived
in a Federal records center.

          2.  Contact.  Provide the name and telephone number of a
person to              contact regarding questions which may arise
during NGS                       processing of the data.

III.  Attachments to the report.  Include as an attachment to the
report a            simple sketch of the project area showing
completed lines, junctions,         and loops.  A section of the
State Index Map of Control Leveling is            sufficient with
progress marked and lines clearly labeled.  Also,       
      attach copies of sketches showing loop closure computations.


             Report Outline for a GPS Control Project

                (See ANNEX L beginning on page L-6)




                                K-5
                Assistance and Mailing Information


The point of contact at NGS for questions concerning the Input
Formats and Specifications of the National Geodetic Survey Data
Base is:


                Mr. Sherrill Snellgrove
                National Geodetic Survey Division              
                NOAA, N/CG124
                1315 East-West Highway, Station 8460
                Silver Spring, Maryland 20910-3282

                Telephone:  (301) 713-3187


GPS, classical horizontal, and/or classical vertical data sent to
NGS via
U.S. Postal Service, United Parcel Service or similar commercial
carrier
should be addressed:

                Chief, National Geodetic Survey Division
                NOAA, N/CG17x2
                1315 East-West Highway, Station 8200
                Silver Spring, Maryland 20910-3282



                             REFERENCE

Gossett, F.R., 1950, rev. 1959: Manual of geodetic triangulation.
   C&GS Special Publication 247, 344 pp.  National Geodetic
Information 
   Branch, NGS, NOAA, Rockville, MD 20852.
























                                K-6

                               ANNEX L

       GUIDELINES FOR SUBMITTING GPS RELATIVE POSITIONING DATA


Global Positioning System (GPS) relative positioning data submitted
to the National Geodetic Survey (NGS) of the National Oceanic and
Atmospheric Administration for inclusion in the National Geodetic
Reference System (NGRS) must meet the following requirements.

1.0  GPS RAW OBSERVATIONS (R-files):  The raw GPS observations will
be sent to NGS in a format specified by NGS at the time of
submission.  Each R-file consists of the set (one or more data
files) of raw GPS data for each unique (independent) occupation of a
station.  For example, if there were four receivers observing during
each of five sessions a total of 20 raw data sets would be
collected.

2.0  GPS VECTOR SOLUTIONS (G-file):  The unadjusted vectors will be
submitted in the format specified in ANNEX N.  Submit one G-file for
each GPS survey project.  The G-file may be generated from one of
the following:  (1) a subroutine of the GPS vector processing
software;  (2) a stand-alone program that reads the printer output
file of the vector processing software; or (3) software that prompts
the user for keyboard entries such as CR8G (NGS 1988).

The G-file contains such information as:  

    (1)  From/to station identification  
    (2)  Vector coordinate differences (DX, DY, DZ), standard
deviations,
        correlations (or covariance data)  
    (3)  Name of processing software and version  
    (4)  Date of solution  
    (5)  Source of the ephemerides  
    (6)  Coordinate system (datum) for the vectors 
    (7)  Method of reduction (i.e., fixed or adjusted orbit
solutions,
        single session or network reduction mode, and single or dual
        frequencies).

When processing data from two stations at a time, the technique is
called the "single" vector processing method.  If one uses this
method for data compiled in the G-file, the G-file may include all
possible unique combinations (independent and dependent) of the
vectors.  With this method there will be n(n-1)/2 possible vectors
for each observing session, where n is the number of receivers
simultaneously observing during the session.  If only the (n-1)
independent vectors are submitted, then every effort must be made to
submit the shortest vectors since these are most likely to be the
results of fixed integer bias solutions.

If processing all data collected during an independent observing
session in a combined multiple vector solution the computation is
called the "session" processing method.  The session G-file entry
would include results for the (n-1) independent vectors, where n is
equal to the number of receivers collecting data simultaneously
during the unique observing session.




                                 L-1
If processing multiple sessions in a combined solution the result is
called a "network" solution.  The G-file would contain (s-1)
independent vectors from each network solution, where s is the total
number of unique stations incorporated in the solution.

The vectors generated in the "fixed orbit" solution mode using
either the "broadcast" (predicted) or "precise" (post fit)
ephemerides will be referenced to the satellite or fiducial station
coordinate system.  The current broadcast ephemeris coordinate
system is known as the World Geodetic System 1984 (WGS 84) (DMA
1987).  All analyses submitted to NGS, including minimally
constrained or "free" adjustments, will be completed in the WGS 84
system or an internationally recognized coordinate system.

3.0  GPS PROJECT AND STATION OCCUPATION DATA FILE (B-file):  Submit
one B-file for each project.  It may be created by using a program
like CR8BB (NGS 1990).  The software functions independently of the
type of receivers used during the project.  
The B-file contains information related to the project (such as
name, location, etc.) and information for each station occupation
[such as observer's initials, model and serial number of equipment,
best estimates for the station coordinates, weather data, antenna
height measurements (vertical), station name, operator comments,
receiver time-offset measurements (if applicable), etc.].  

B-file formats are described in Volume I, Chapter 2.

4.0  STATION DESCRIPTION FILE (D-file):  Create one D-file for each
GPS project.  This file contains descriptive or recovery information
for each station visited during the GPS survey.  It would include
any points connected to the GPS survey using conventional horizontal
surveying and/or differential leveling techniques, and miscellaneous
reports for NGRS points visited but not occupied during the GPS
survey.  Submit the file in agreement with the format described in
volume I, Chapter 3 and annexes C, D and I. 

New descriptions should be created using program DESC which is part
of a set of programs called DDPROC (NGS 1992).  Descriptive data for
existing NGRS points in a project area should be requested from NGS
prior to starting reconnaissance.  The data can be downloaded from
the NGS data base and converted to a form usable by the DESC program
for updating purposes.

5.0  HORIZONTAL CONNECTION SURVEY DATA FILE (T-file):  A T-file must
be created and submitted with the GPS project if the project
includes any surveys observed with conventional (terrestrial)
horizontal surveying techniques.  For example, if an existing
station was not a suitable GPS site and an offset point was used,
the data compiled in the T-file would be for the horizontal tie
between the two points.  The T-file may be created with MTEN (NGS
1991b). 

T-file formats are described in volume I, chapters 1 and 2. 

6.0  VERTICAL CONNECTION SURVEY DATA FILE (L-file):  If the GPS
survey project includes observations using conventional differential
leveling techniques, an 
L-file must be created and submitted with the GPS project data.  For
example, if a bench mark could not be occupied directly with a GPS
receiver system and an offset point was set, part of the data
entered connecting the two points together would be for the leveling
observations between the two points.  


                                 L-2
If only one NGRS vertical point (bench mark) was leveled to at a GPS
station site, the leveling data will be considered part of the GPS
survey.  If a good two-bench mark tie is made to the NGS Vertical
control network, the leveling will be considered as a vertical
control survey.  Formats for these data are in Volume II.

Create the L-file with NGS software called PCvOBS (NGS 1989).  Note
that this program is to be used in place of program MTEN.

7.0  ANALYSIS AND ADJUSTMENT DATA:  

7.1  Loop misclosures and differences in repeat vector measurements
will be computed and evaluated to check for blunders or significant
errors in vectors. They are also used to obtain initial estimates of
the consistency of the GPS survey network.  They will be done in
agreement with the "Office Procedures" of the "Geometric Accuracy
Standards and Specifications for GPS Relative Positioning Surveys"
(FGCC 1989).  Note that these checks are not an indication of
accuracy but rather a measure of precision or repeatability.

Particular attention shall be given to detection of possible
blunders caused by antenna offset measurements (vertical) and/or
centering errors (horizontal).  A tabulation of the results of the
loop misclosures and repeat vector comparisons will be included in
the project report.  The loop misclosures may be evaluated with NGS
software called LOOP (NGS 1991a) or its equivalent.

7.2  A minimally constrained (free) least squares, three dimensional
(3D) adjustment (one station arbitrarily selected and held equal to
known, i.e published, NGRS coordinates) will be completed in
accordance with the "Office Procedures" of the "Geometric Accuracy
Standards and Specifications for GPS Relative Positioning Surveys"
(FGCC 1989).  

Submit a computer listing (burst and bound) that shall clearly
include at least the following:  

    (a) Input vector component data.  (Depending on adjustment
software
        used, this may include variance-covariance data.)
    (b) The "a priori" standard errors used if variance-covariance
data were
        not used.  
    (c) Station list with name (abbreviated as appropriate), project
unique
        four-character identification code, project unique numeric
code used
        in adjustment, initial coordinates (latitude, longitude, and
height
        above ellipsoid), and the fixed station specified.  
    (d) Adjusted vectors with residuals (v) and normalized residuals
(v').
    (e) "A posteriori" variance of unit weight of the adjustment.
    (f) Adjusted coordinates for each station including the station
held
        fixed in the "free" adjustment.  
    (g) Datum for the satellite coordinate system (e.g., WGS 84).  
    (h) The reference ellipsoid used in the adjustment.  (e.g. WGS
84 or
        GRS 80) 
    (i) Other appropriate data or statistics.

The estimate of the variance factor ("a posteriori" variance of unit
weight) should be less than 2 in the "free" (minimally constrained)
adjustment.  It may range between 1 and 16 or more depending upon
how close the variance estimates for the vector components of the
vector solutions are to the true values.


                                 L-3
Estimates which are optimistic (i.e., too small) will result in
higher variance factor values.  Show clearly the name and version of
the 3D adjustment software used.

7.3  A constrained 3D adjustment shall be submitted if project
specifications require the computation of adjusted coordinates for
the new points in relation to the local datum.  A constrained
adjustment for a project in North or Central America involves
adjusting the GPS vector data while constraining stations to the
existing network of NGS published horizontal coordinate data in the
North American Datum of 1983 (NAD 1983) system and NGS published
vertical data in the North American Vertical Datum of 1988 (NAVD
1988) system or their successors.

The unknown orthometric heights will be determined by the most
appropriate method for achieving the specified accuracy standard for
the project.  This will usually involve one of two methods.  The
first method incorporates "a priori" geoidal undulation data in the
3D adjustment while holding fixed the orthometric heights for
stations with known values (determined by differential leveling
techniques).  The source for the geoidal separation data (e.g.,
GEOID 93) must be given.  This includes the name of software,
version, and data used for computing the geoidal separation.  

The second method for determining orthometric heights from GPS
vector data involves performing 3D adjustments using no geoidal
undulation data.  In this method, the orthometric heights are held
fixed while using zero values for the geoid height above the
ellipsoid in the 3D adjustment.  This forces the GPS network to fit
to the geoidal surface.  The success of achieving the specified
accuracy standard for the orthometric heights at the points with
unknown values will depend upon the flatness of the geoid in the
project area and the distribution of the stations with known
orthometric heights.  This method is discussed in more detail in the
article "On the use of GPS vectors in densification adjustments"
(Vincenty 1987).

A tabulated listing of stations and fixed and adjusted coordinate
values must be provided.  The project report must give a description
of the method used to estimate the orthometric heights. 

8.0  PROJECT SKETCH:  A sketch will be drawn in black ink on white
paper showing all stations occupied during the GPS survey.  The
sketch will have a border drawn around the edge and must include
grid ticks for latitude and longitude.  Use the following standard
symbols for the stations:  

    (a) Squares for existing vertical network control
    (b) Open triangles for existing horizontal control stations
    (c) Open triangles within squares for existing
horizontal/vertical
        stations
    (d) Closed triangles for GPS stations
    (e) Circles for stations occupied during previous GPS projects

A "D" next to the station symbol will be used to indicate a Doppler
station that has point-position coordinates determined using
"precise" ephemerides. (Contact NGS for a list of Doppler stations
with "precise" ephemerides point position coordinates located in
North America.)




                                 L-4
Besides the stations occupied, the sketch should show other stations
of the existing network located within or near the project area. 
Specify in the project report whether any attempt was made to
recover these stations.  The report must state why the recovered
stations were not occupied.  To show a station that was not
recovered use "NR" next to that station's symbol.  The sketch shall
include a boxed-in legend that gives:  

    (a) project name
    (b) general locality
    (c) name of group making observations
    (d) project leader
    (e) month/year (from-to)
    (f) scale of sketch
 
On a copy of the sketch, form closed loops of all (if practical)
"independent" (non-trivial) GPS vectors measured.  Show vectors
common to an observing session with different line types (dashed,
dotted, etc., or other clear graphic depiction).  Show, next to one
or more of the independent lines for each session, the observing day
number/session designation (e.g., 242B, 321C, 3331, 3332, etc.).

Survey points will be shown in an inset sketch when they are too
close together to be depicted clearly on the network sketch.  The
project sketch(es) will be included with the project report.

9.0  PROJECT REPORT:  The project report will be submitted in a
binder with the project name on the front of the binder and will be
structured in the following manner:

I.   Introduction

        A. Purpose - Describe the purpose for which the survey was
        conducted.
        Show the name of the organization for which the survey was
        performed.

        B. Time Period - State the arrival and departure dates for
        the field crew
        and dates of first and last observing sessions.

        C. Point of Contact - Supply the name, phone number, and
        mailing address
        of the point of contact within the submitting organization. 
        Supply the
        same information for all organizations which participated in
        the survey.

        D. Accuracy standards - Provide the accuracy standards
        (vertical and
        horizontal) specified for the project.

II.   Location - Describe the geographic location and scope of the
project in
     general terms.

III.  Conditions Affecting Progress - Specify equipment failures,
climate,
     scope of project, site accessibility, reconnaissance,
malfunctioning
     satellites, etc.

IV.   Field Work

        A. Chronology - Give a brief description of the progression
        of the
        project.

                                 L-5
        B. Instrumentation - Describe the make, model, and serial
        number of each
        receiver used on the project.

        C. Deviation from Instructions - Describe any deviation from
        the
        procedures and specifications stated in the project
        instructions.  Specify all stations which were eccentrically
        occupied and state why the
        station(s) could not be directly occupied.  

V.    Data Processing Performed - Describe the data processing that
was done. 
     Include tasks such as transferring of data to different storage
media,
     data quality checking, station descriptions, vector
determinations, and
     closure computations.  Specify the ephemeris type [broadcast
(predicted)
     or precise (post fit)] and the source.

     Complete the following sections as appropriate:

        A. Software Used - Specify all software by program name and
        version number which was used to acquire, manage, reduce,
        adjust, and submit field data.  If the project data were
        reduced or acquired with different versions of a program,
        specify which version was used with which block of data.

        B. Rejected Data - Specify observing sessions which were
        rejected and
        reobserved.  Include the reason(s) why the data from a
        particular session were rejected. 

        C. Equipment - Describe by manufacturer, model number, and
        serial number
        all receivers used to collect the data.  Indicate any
    equipment failures
        which may have degraded the quality of data and/or vector
        determinations
        which were retained.  Specify the data or vectors by station
    and session, and the failed equipment by component and
        serial number.  Indicate data     rejected because of
        equipment failure in section B above.

        D. Weather - Tabulate required meteorological observations
    for the survey and include a copy with this report.  List
            all observing sessions which occurred during periods of
            changing or severe weather conditions such as passing
            fronts, storms, etc.  A simple table listing the
            sessions influenced and the weather condition will
            suffice.

        E. Adjustment - Discuss in detail the type(s) of
    adjustment(s)performed.  Show weighting technique used,
                 station(s) constrained, method used to estimate
                 orthometric heights and existence of independent
                 sub-networks.  Discuss possible weaknesses or
                 distortions found or suspected in the NGRS.

        F. Closures - Tabulate the results of all loop misclosure
    computations.
        Include the vectors used, vector length, maximum closure
        error in each
        component, and average closure error in each component. 
        Tabulate closure component error in terms of Cartesian
        coordinates (XYZ) and in terms of the local terrestrial
        system [N,E,U (north, east, up)].  Also, tabulate
        comparisons of repeat vectors observed indicating vector
        length, and maximum and average closure for each vector
        component.  Closures will be stated in both meters and parts
        per million.



                                 L-6
VI.   Statistics

        A. Stations Occupied - List station names and give total
    stationsoccupied based on each of the following categories:

            1.  Existent NGRS horizontal stations
            2.  Existent NGRS vertical stations
            3.  Existent NGRS horizontal/vertical stations
            4.  Stations established
            5.  Stations previously occupied with GPS

        B. Base lines Observed - Compute the total number of
    independent (non-trivial) vectors observed during the
                     project.  Each observing session
        cannot have more than (N - 1) independent vectors, where
        N = number of
        receivers.  For example, if a project included 10 observing
        sessions and 4 receivers were used during each session, a
        total of 10(4-1) = 30
        independent vectors would have been observed.

        C. Provide the total number of observing days and total
        number of
        sessions.  For example, if the total number of observing
    days was 5 and
        there were 2 sessions conducted each observing day, then the
        total number of observing sessions was 5 x 2 = 10.

VII.  Comments and Recommendations

      Include noteworthy comments and recommendations regarding the
execution
     of the GPS survey for this project (or future projects) not
found
     elsewhere in the project report.

VIII. Attachments and Enclosures

        A. Station List - Include a table which lists the station
        name, four-
        character station identifier, coordinates, elevation,
        session(s) occupied, and station type for all stations
        occupied.  The list will be alphabetical by four-character
        identifier.  See "Planning GPS Surveys" for instructions on
        preparation of station lists (NGS 1986).

        B. Field Project Sketch - Attach a copy of the project
        sketch.  If there
        are multiple copies of the sketch showing different data,
        attach a copy of each.  See "Planning GPS Surveys" for
        instructions on preparation of
        survey sketches (NGS 1986). 

        C. Project Instructions - Attach a copy of the instructions
        and/or
        contract under which this project was performed.  Also
        include any      revisions or changes to the instructions or
        specifications.

        D. Field Logs - Provide original or clear copies of field
        survey notes,
        record books, and observation logs.  When appropriate, this
        will include
        Log of Time Offset Measurements and Log of Surface
        Meteorological
        Measurements.

        E. Equipment Failure Logs - Include with the report a
        failure log for any equipment used to gather data which
        failed anytime during the project.  The log will state the
        name of the component, serial number, date of failure and
        nature of failure.

                                 L-7
        F. Project Observing Schedule - Prepare a list which
        summarizes the
        following: observing day numbers/session letters, four-
        character station
        identifiers, start and stop dates and times (UTC),
        satellites observed      (PRN numbers), receiver serial
        numbers, antenna offset measurements,
        remarks, etc.



     
********************************************************************
****
      *                                                              
       *
      *  All data and material submitted must be neat and legible
(typed or  *
      *  clearly written in black ink).  DO NOT SEND THE ONLY COPY
OF ANY    *
      *  PAPER RECORDS OR DIGITAL DATA FILES.                        
       *
      *                                                              
       *
     
********************************************************************
****



10.0  PROJECT SUBMISSION CHECKLIST:  Exhibit A is a form that may be
used to check for completeness when submitting GPS project data to
the National Geodetic Survey.

11.0  DATA TRANSMISSION MEDIA:  All computer-generated digital data
files must be submitted to the NGS in digital form on media approved
by NGS at time of submission.


If you have questions concerning the above requirements, please
contact:


                     Ms. Madeline White
                     National Geodetic Survey Division             
                     NOAA, N/CG144
                     1315 East-West Highway, Station 8342
                     Silver Spring, Maryland 20910-3282

                     Telephone:  (301) 713-3211




















                                 L-8
EXHIBIT A

                    PROJECT SUBMISSION CHECKLIST
                            GPS PROJECTS

Project Title:       _____________________________________________

Accession Number:    _____________________________________________

Submitting Agency:   _____________________________________________

Observing Agency:    _____________________________________________

Receiver Type:       _____________________________________________

                          PACKAGE CONTENTS

Project Report and Attachments                        Required For

( )  Project Report                                   All Projects
( )  Project Sketch                                   All Projects
( )  Project Instructions or Contract Specifications  All Projects
( )  Final Station List                               All Projects
( )  Station Visibility Diagrams                      All Projects
( )  Final Observing Schedule                         All Projects
( )  Observation Logs                                 All Projects
( )  Equipment Failure Logs                           NGS Projects
( )  Loop Misclosures or Adjustment Analysis          All Projects
( )  Minimally Constrained Adjustment                 All Projects
( )  Constrained Adjustment                           If Specified
( )  Meteorological Instrument Comparison Logs        If Specified
( )  Photographs of Views from Stations               If Specified
( )  Photographs or Rubbings of Station Marks         All Projects
( )  COMPGB Output (Validation program-B/G file)      All Projects
( )  OBSDES Output (Validation program-D-file)        All Projects

Digitized Data Files  (  ) Diskettes   (  ) Other:_________________ 


( )  Raw Phase Data (R-files)                         All Projects
( )  Base Line Vectors (G-file)                       All Projects
( )  Project and Station Occupation Data (B-file)     All Projects
( )  Descriptions or Recovery Notes (D-file)          All Projects
( )  Terrestrial Horizontal Observations (T-file)     If Applicable
( )  Differential Leveling Observations (L-file)      If Applicable

Comments - Enter on the reverse side of this form.


                Org Code      Name                         Date

Received by: ______________________________________________________

Reviewed by: ______________________________________________________ 
                                                                   
Reviewed by: ______________________________________________________

                                 L-9
REFERENCES:


Defense Mapping Agency, 1987:  Department of Defense World Geodetic
System
  1984 - its definition and relationships with local geodetic
systems.  DMA
  Technical Report, DMA TR 8350.2, 30 September 1987, Washington,
DC, 121 pp.

Federal Geodetic Control Committee, 1989:  Geometric Accuracy
Standards
  and Specifications for GPS Relative Positioning Surveys, version
5.0: May
  11, 1988, reprinted with corrections August 1, 1989, 48 pp. 

National Geodetic Survey, 1992:  "Program DDPROC and Documentation,"
version
  2.0: December 10, 1992. 

National Geodetic Survey, 1991a:  "Program LOOP and Documentation,"
version
  4.03: January 18, 1991.  

National Geodetic Survey, 1991b:  "MTEN4, A System for Use with the
National
  Geodetic Survey Data Base Input Formats and Specifications",
version 20:
  December, 1991.

National Geodetic Survey, 1990:  "Guidelines for Digitizing GPS
Project and
  Station Occupation Information using program CR8BB," version 3.21:
July 26,
  1990.  

National Geodetic Survey, 1989:  "PCvOBS Software and
Documentation," version
  2.00: October 10, 1989.

National Geodetic Survey, 1988:  "Program CR8G and Documentation,"
version
  1.1: December 27, 1988. 

National Geodetic Survey, 1986:  "Planning GPS Surveys," version 2,
September
  26, 1986 (NGS preliminary document).

Vincenty, T., 1987:  "On the use of GPS vectors in densification
adjustments,"
  Surveying and Mapping (Journal of the American Congress on
Surveying and
  Mapping), Vol. 47, No. 2, pp. 103-108.



NOTE: All National Geodetic Survey and Federal Geodetic Control
Subcommittee publications are available from:

        NOAA, National Geodetic Information Branch, N/CG174
        1315 East-West Highway, Room 9202
        Silver Spring, MD 20910-3282.

        phone:  301-713-3242
        fax:    301-713-4172







                                L-10
                             ANNEX N

         GLOBAL POSITIONING SYSTEM DATA TRANSFER FORMAT
                            (G-FILE)

This annex contains information about the Global Positioning
System (GPS) Data Transfer Format (G-File) records.  The G-File
consists of eight 80-column record types that are used to
document the results of the computation of relative vectors,
expressed as components, from simultaneously observed GPS phase
measurements.  There may be only one G-file for a project.  Each
G-file must contain one Project Record (A) and one or more
Session Header Records (B).  A Session Header Record (B) is
required for each individually processed vector or each
simultaneously processed group of vectors (session) at three or
more survey points.  Each Session Header Record is followed by
one or more Vector (C) and/or Long Vector (F) Records,
Correlation (D) or Covariance (E) Records, optional Coordinate
(G) Records, and optional and/or required Station Information (H)
Records.  Vector and Long Vector Records contain relative vector
components between two survey points.  Correlation Records
contain the off-diagonal elements only of the correlation matrix
for the vector components in a session.  Covariance Records
contain the off-diagonal elements only of the covariance matrix
for the vector components in a session.  The records for a
simultaneously processed vector set may only contain correlation
or covariance records but not a mix of the two.  A Long Vector
Record may only be used when a vector component is larger than
+/- 999,999.9999 meters.  The Coordinate (G) Records may be used
to record, for informational purposes within the G-file, the
coordinates of survey points held fixed during the vector
computations or to provide location information regarding the
G-file.  Relative vectors are required even if coordinates are
included.  Station Information Records are used to document
differing conditions or solution types for vectors within a
session.  The Station Information Record (H) is required only
when an external time standard is used with a receiver, when a
comment needs to be made about a station occupation, or when
information about a station occupation or vector solution is not
the same as for all other stations or vectors in a session. 
Multiple H records are allowed.  

This annex documents the record formats, provides an explanation
of the fields within each record, and gives G-file examples using
the various record types.

CC-1 CODE    RECORD TYPE 
 
   A         Project Record             (The A record is
                                        required)
   B         Session Header Record           (The B record is
                                             required)
   C         Vector Record              (The C record is
                                        required)
   D         Correlation Record         (Either the D record or
                                        the
   E         Covariance Record           E record is required)
   F         Long Vector Record
   G         Coordinate/Absolute Position Record (optional)
   H         Station Information Record 








                               N-1Project Record 

01-01  A 
02-03  Job Code (Chapter 1)                               Alpha
04-07  Year,  Start of Project (local) (CCYY)             Integer
08-09  Month, Start of Project (local) (MM)               Integer
10-11  Day,   Start of Project (local) (DD)               Integer
12-15  Year,  End of Project (local)   (CCYY)             Integer
16-17  Month, End of Project (local)   (MM)               Integer
18-19  Day,   End of Project (local)   (DD)               Integer
20-78  Title of project                                   Alpha
79-80  Reserved

Session Header Record

01-01  B
02-05  Year,  First Actual Measurement (UTC) (CCYY)       Integer
06-07  Month, First Actual Measurement (UTC) (MM)         Integer
08-09  Day,   First Actual Measurement (UTC) (DD)         Integer
10-13  Time,  First Actual Measurement (UTC) (HHMM)       Integer
14-17  Year,  Last Actual Measurement  (UTC) (CCYY)       Integer
18-19  Month, Last Actual Measurement  (UTC) (MM)         Integer
20-21  Day,   Last Actual Measurement  (UTC) (DD)         Integer
22-25  Time,  Last Actual Measurement  (UTC) (HHMM)       Integer
26-27  Number of Vectors in the Session                   Integer
28-42  Software Name & Version                            Alpha
43-47  Orbit Source (agency)                              Alpha
48-51  Orbit accuracy estimate (XXX.x meters)     Implied Decimal
52-53  Solution coordinate system code   (table, N-6)     Integer
54-55  Solution meteorological use code  (table, N-6)     Integer
56-57  Solution ionosphere use code      (table, N-6)     Integer
58-59  Solution time parameter use code  (table, N-6)     Integer
60-60  Nominal accuracy code             (table, N-8)     Integer
61-66  Processing agency code            (Annex C)        Alpha
67-70  Year of Processing                (CCYY)           Integer
71-72  Month of processing               (MM)             Integer
73-74  Day of processing                 (DD)             Integer
75-80  Solution Type                     (table, N-7)     Alpha 


Note:  Columns 52 through 80 of Record B assume all stations use
identical observing and computation procedures.  If this is not
the case use Record H
to record the differences for each of those stations which vary
from those conditions noted on the B record.












                               N-2Vector Record 

01-01  C 
02-05  Origin Station Serial Number (ssn)  (vector tail)  Integer
06-09  Differential Station Serial Number  (vector head)  Integer
10-20  Delta X            (XXXXXXX.xxxx meters)   Implied Decimal
21-25  Standard Deviation (X.xxxx meters)         Implied Decimal
26-36  Delta Y            (XXXXXXX.xxxx meters)   Implied Decimal
37-41  Standard Deviation (X.xxxx meters)         Implied Decimal
42-52  Delta Z            (XXXXXXX.xxxx meters)   Implied Decimal
53-57  Standard Deviation (X.xxxx meters)         Implied Decimal
58-58  Rejection Code (use upper case R to reject)        Alpha
59-68  Origin Station Data Media Identifier       (See page N-6)
69-78  Differential Station Data Media Identifier (See page N-6) 
79-80  Reserved 

Note: Standard deviation values must be positive, non-zero
numbers.

Correlation Record 

01-01  D 
02-04  Row Index Number                                   Integer
05-07  Column Index Number                                Integer
08-16  Correlation         (XX.xxxxxxx)           Implied Decimal
17-19  Row Index Number                                   Integer
20-22  Column Index Number                                Integer
23-31  Correlation         (XX.xxxxxxx)           Implied Decimal
32-34  Row Index Number                                   Integer
35-37  Column Index Number                                Integer
38-46  Correlation         (XX.xxxxxxx)           Implied Decimal
47-49  Row Index Number                                   Integer
50-52  Column Index Number                                Integer
53-61  Correlation         (XX.xxxxxxx)           Implied Decimal
62-64  Row Index Number                                   Integer
65-67  Column Index Number                                Integer
68-76  Correlation         (XX.xxxxxxx)           Implied Decimal
77-80  Reserved 

Note:  This record is to record the off-diagonal correlates only
from the session (or vector) correlation matrix.  Since the
correlation matrix is symmetric about the diagonal only the upper
or the lower half should be recorded.














                               N-3Covariance Record

01-01  E
02-04  Row Index Number                                   Integer
05-07  Column Index Number                                Integer
08-19  Covariance  (XXXX.xxxxxxxx meters2)        Implied Decimal
20-22  Row Index Number                                   Integer
23-25  Column Index Number                                Integer
26-37  Covariance  (XXXX.xxxxxxxx meters2)        Implied Decimal
38-40  Row Index Number                                   Integer
41-43  Column Index Number                                Integer
44-55  Covariance  (XXXX.xxxxxxxx meters2)        Implied Decimal
56-58  Row Index Number                                   Integer
59-61  Column Index Number                                Integer
62-73  Covariance  (XXXX.xxxxxxxx meters2)        Implied Decimal
74-80  Reserved

Note:  This record is to record the off-diagonal covariances only
from the vector variance-covariance matrix.  The square root of
the diagonal elements, the component standard deviations, are
recorded on records C and F.  Since the variance-covariance
matrix is symmetric about the diagonal only the upper or the
lower half should be recorded.


Long Vector Record

01-01  F
02-05  Origin Station Serial Number (ssn) (vector tail)   Integer
06-09  Differential Station Serial Number (vector head)   Integer
10-22  Delta X            (XXXXXXXXX.xxxx meters) Implied Decimal
23-27  Standard Deviation (X.xxxx meters)         Implied Decimal
28-40  Delta Y            (XXXXXXXXX.xxxx meters) Implied Decimal
41-45  Standard Deviation (X.xxxx meters)         Implied Decimal
46-58  Delta Z            (XXXXXXXXX.xxxx meters) Implied Decimal
59-63  Standard Deviation (X.xxxx meters)         Implied Decimal
64-64  Rejection Code (use upper case R to reject)        Alpha
65-65  Origin station manufacturer code                   (N-6)
66-68  Origin station UTC day of year of occupation (DDD) Integer
69-69  Origin station year of occupation (Y) UTC          Integer
70-70  Origin station session indicator                   Alpha  
71-71  Differential station manufacturer code             (N-6)
72-74  Differential station day of year (DDD) UTC         Integer
75-75  Differential station year of occupation (Y) UTC    Integer
76-76  Differential station session indicator             Alpha  
77-80  Reserved

Note: Standard deviation values must be positive, non-zero
numbers.









                               N-4Coordinate Record

01-01  G 
02-02  Blank
03-03  Record usage code K - see below
04-05  Blank
06-09  Station Serial Number
10-10  Blank
11-14  Optional "short" station name - see below
15-15  Blank
16-20  Coordinate frame designator (e.g. NAD 83, WGS 84, NAD 27,
       WGS 72, ITR 90, etc.; inquire for additions)
21-21  Blank
22-33  X coordinate (XXXXXXXX.xxxx meters)        Implied Decimal
34-34  Blank
35-46  Y coordinate (YYYYYYYY.yyyy meters)        Implied Decimal
47-47  Blank
48-59  Z coordinate (ZZZZZZZZ.zzzz meters)        Implied Decimal
60-60  Blank
61-64  Sigma X (SS.ss m) blank if unknown or greater than 99.99 m
65-65  Blank
66-69  Sigma Y (SS.ss m) blank if unknown or greater than 99.99 m
70-70  Blank
71-74  Sigma Z (SS.ss m) blank if unknown or greater than 99.99 m
75-80  Reserved

K = 0 or blank indicates that the position is approximate and has
no particular interpretation.
K = 1 indicates that these are exact coordinates (to 0.1 mm) used
during
the processing of the G-file vectors.

The 4 character "short" name, if used, should be the same
abbreviation used elsewhere in the G-file or other related data
files.



Station Information Record

01-01  H
02-05  Station Serial Number (ssn)                        Integer
06-09  Four Character Identifier                          Alpha
10-11  External frequency standard code (table, N-8)
12-13  Vector meteorological use code   (table, N-6)
14-15  Vector time parameter use code   (table, N-6)
16-17  Vector ionosphere use code       (table, N-6)
18-23  Vector Solution type             (table, N-7)
24-78  Comments                                           Alpha
79-80  Reserved

Use comment field to record clarifying information or instrument
type if noted as "other" in Data Media Identifier.





                               N-5CODE TABLES

Solution Coordinate Reference System Codes

01 -- WGS 72 Precise (post-fit) Ephemeris
02 -- WGS 84 Precise (post-fit) Ephemeris
03 -- WGS 72 Broadcast (Predicted) Ephemeris
04 -- WGS 84 Broadcast (Predicted) Ephemeris
05 -- ITRF 89 Epoch 1988.0 (International Earth Rotation Service
      Terrestrial Reference Frame 1989, epoch 1988.0 [July 1989])
06 -- PNEOS 90 (Provisional National Earth Orientation Service
      Terrestrial Reference Frame 1990 [March 1991])
07 -- NEOS 90 Epoch 1988.0 [July 1991]
08 -- ITRF 91 Epoch 1988.0 [July 1992]
09 -- Scripps Institute of Oceanography-Massachusetts Institute of
Technology
     (SIO-MIT) 1992, epoch 1992.5 [September 1992]
10 -- ITRF 91 Epoch 1992.6
11 -- ITRF 92 Epoch 1994.0 [January 1994]

Solution Meteorological Use Codes 

01 -- Default values used (model used)
02 -- Observed meteorological data used 
03 -- Water vapor radiometer used

Solution Ionosphere Use Code 

01 -- None 
02 -- Dual frequency ionospheric correction used
03 -- Ionospheric model used

Solution Time Parameter Use Codes 

01 -- Observed time synchronization data used 
02 -- Time parameters solved for in data reduction 

Data Media Identifier

    Required format: ADDDYSCCCC

where, A    is one of the following characters which indicates the
manufacturer
          of the receiver used for the observation:
            A = Ashtech, Inc; C = Topcon Corp; D = Del Norte
            Technology, Inc;
            G = Allen Osborne Associates, Inc; I = Istac, Inc;
            L = MINI-MACR; M = MACROMETERR; N = Norstar Instruments
            Ltd;
            O = Motorola, Inc; R = Trimble Navigation, Ltd; S =
            SERCEL, Inc;
            T = Texas Instruments, Inc; V = NovAtel Communications
            Ltd;
            W = Leica Heerbrugg AG/Wild Heerbrugg/Magnavox, Inc; X
            = other
       DDD  is the day of the year of the first data epoch (UTC)
       Y    is the last digit of the year of the first data epoch
(UTC)
       S    is an alphanumeric designation of the session
       CCCC is the project unique, four character abbreviation of a
station
            designation


                                 N-6CODE TABLES (continued)

Solution Type Use Codes

   + L1TD--    L1SDFL     L1DDFL     IFDDFL     OTDDFL     K1DDFX
   + L2TD--    L1SDFX     L1DDFX     IFDDFX     OTDDFX     K2DDFX
   + IFTD--    L1SDPF     L1DDPF     IFDDPF     OTDDPF     KIDDFX
   + WLTD--                                                KWDDFX
                          L2DDFL     WLDDFL                P1DDFX
                          L2DDFX     WLDDFX                P2DDFX
                          L2DDPF     WLDDPF                PIDDFX
                                                           PWDDFX

    Where:  L1 = Frequency 1 
            L2 = Frequency 2 
            IF = Ionosphere Free Combination  (Static) *
            WL = Wide Lane Combination (Static or Rapid Static)**
            OT = Other (Explain in Station Information Record)

            K1 = L1 Kinematic Observation (Single visit,
                 continuous lock - also known as Continuous
                 Kinematic, Stop and Go Kinematic, or On-the-Fly
                 Kinematic)
            K2 = L2 Kinematic
            KI = Ionosphere Free Combination Kinematic *
            KW = Wide Lane Combination Kinematic **

            P1 = L1 Pseudo-kinematic (Two or more visits,
                 intermittent lock - also known as Pseudo-
                 static, Intermittent Static or Reoccupation
                 techniques)
            P2 = L2 Pseudo-kinematic
            PI = Ionosphere Free Combination Pseudo-kinematic *
            PW = Wide Lane Combination Pseudo-kinematic **

            TD = Triple Difference Solution
            DD = Double Difference Solution
            SD = Single Difference Solution

            FL = Float (real number) estimate of biases
            FX = Fixed integer estimate of biases
            PF = Partial, fixed integer estimate of biases
                 (Not all integer biases determinable).

+  Triple Difference Solutions have no integer ambiguities, leave
   trailing columns blank.
*  IF = ionosphere free = {f21/(f21 - f22)}L1 - {f1f2/(f21 - f22)}L2
** WL = wide lane = L1 - L2

   Where, f1 = 1575.42 mHz, f2 = 1227.60 mHz, and L1 and L2 are
phase    measurements in units of cycles.


                               N-7CODE TABLES (continued)

External Frequency Standard

01 -- No external frequency standard used
02 -- Rubidium frequency standard used
03 -- Cesium frequency standard used
04 -- Hydrogen Maser frequency standard used
05 -- External crystal frequency standard used
06 -- Other (Comment in Station Information Record)

Vector Nominal Accuracy Codes 
                                                Order/Class
4 -- Intended accuracy  100 ppm plus 5.0 cm        3
3 -- Intended accuracy   50 ppm plus 3.0 cm        2-II
2 -- Intended accuracy   20 ppm plus 2.0 cm        2-I
5 -- Intended accuracy   10 ppm plus 1.0 cm        1
6 -- Intended accuracy    1 ppm plus 0.8 cm        B
7 -- Intended accuracy  0.1 ppm plus 0.5 cm        A
8 -- Intended accuracy 0.01 ppm plus 0.3 cm        AA




































                               N-8PROJECT RECORD

 1     2 3   4             11  12             19 20
Ŀ   Ŀ Ŀ  Ŀ Ŀ
       
RECORD JOB   C C Y Y M M D D    C C Y Y M M D D                PROJECT TITLE
TYPE  CODE       START                END
(A)             PROJECT             PROJECT
                                                                                78   79 80
     Ŀ   Ŀ
        
                                PROJECT TITLE CONTINUED                              

-------------------------------------------------------------------------------------------
GROUP HEADER RECORD

 1     2             9    10     13     14             21  22     25
Ŀ   Ŀ   Ŀ     Ŀ  Ŀ
             
RECORD C C Y Y M M D D     H H M M       C C Y Y M M D D    H H M M
TYPE   DATE OF FIRST     TIME OF FIRST    DATE OF LAST    TIME OF LAST 
(B)     OBSERVATION       OBSERVATION     OBSERVATION     OBSERVATION
 
26 27   28                           42 43       47  48       51      52 53        54 55
Ŀ   Ŀ Ŀ  Ŀ Ŀ      Ŀ        Ŀ
      .              
NUMBER           SOFTWARE ID               ORBIT      X X X   x       COORDINATE    MET.
  OF             AND VERSION               SOURCE    ORBIT ACCURACY   SYSTEM        USE
VECTORS                                                (METERS)       CODE          CODE
 
56 57          58 59          60     61         66 67             74  75         80
Ŀ          Ŀ          Ŀ    Ŀ Ŀ  Ŀ
                           
IONOSPHERE  TIME PARAMETER  ACCURACY   PROCESSING   C C Y Y M M D D      SOLUTION
USE CODE       CODE           CODE       AGENCY     PROCESSING DATE        CODE




                                             N-9VECTOR RECORD


 1     2     5   6     9   10                     20  21         25 26                    
36
Ŀ   Ŀ Ŀ  Ŀ Ŀ  Ŀ Ŀ Ŀ
Ŀ
      .  .
.
RECORD  ORIGIN DIFFERENTIAL X X X X X X X   x x x x    X   x x x x   X X X X X X X   x x x x
TYPE     SSN       SSN         DELTA X                   SIGMA X        DELTA Y        
(C)                            (METERS)                  (METERS)       (METERS)

37         41 42                     52  53         57   58    59                 68
Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ   Ŀ   Ŀ
. .  .        
 X   x x x x   X X X X X X X   x x x x    X   x x x x   REJECT  ORIGIN STATION DATA
   SIGMA Y        DELTA Z                   SIGMA Z      CODE    MEDIA IDENTIFIER      
   (METERS)       (METERS)                  (METERS)

69                 78 79 80
Ŀ Ŀ
 
DIFFERENTIAL STATION  BLANK
DATA MEDIA IDENTIFIER

















                                            N-10CORRELATION RECORD

 1      2   4   5   7   8                 16  17   19 20   22 23                 31 32   34
Ŀ    Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ Ŀ Ŀ Ŀ
      .    . 
RECORD   ROW   COLUMN   X X   x x x x x x x     ROW   COLUMN   X X   x x x x x x x    ROW
TYPE    INDEX  INDEX       CORRELATION         INDEX  INDEX      CORRELATION         INDEX
(D)      NO.    NO.                             NO.    NO.                            NO.

35   37 38                 46  47   49 50   52 53                 61 62   64 65   67
Ŀ Ŀ Ŀ  Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ
 .    .   
COLUMN   X X   x x x x x x x     ROW   COLUMN   X X   x x x x x x x    ROW   COLUMN
INDEX       CORRELATION         INDEX  INDEX       CORRELATION        INDEX  INDEX
 NO.                             NO.    NO.                            NO.    NO.

68                 76 77     80
Ŀ Ŀ Ŀ
. 
 X X   x x x x x x x     BLANK
     CORRELATION


















                                            N-11COVARIANCE RECORD

 1      2   4   5   7   8                       19  20   22 23   25 
Ŀ    Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ
      .   
RECORD   ROW   COLUMN   X X X X   x x x x x x x x     ROW   COLUMN 
TYPE    INDEX  INDEX        COVARIANCE               INDEX  INDEX  
(E)      NO.    NO.         (METERS2)                 NO.    NO.
    
26                       37 38   40 41   43 44                       55 56   58 59   61
Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ Ŀ
.   .  
 X X X X   x x x x x x x x    ROW   COLUMN   X X X X   x x x x x x x x    ROW   COLUMN 
      COVARIANCE             INDEX  INDEX        COVARIANCE              INDEX  INDEX
      (METERS2)               NO.    NO.         (METERS2)                NO.    NO.

62                       73 74     80     
Ŀ Ŀ Ŀ                               
. 
 X X X X   x x x x x x x x    BLANK
      COVARIANCE
      (METERS2)

















                                            N-12LONG VECTOR RECORD                                                                     
                                                                                      
 1      2     5    6     9    10                         22  23         27
Ŀ    Ŀ  Ŀ   Ŀ Ŀ  Ŀ Ŀ
         .  .
RECORD   ORIGIN  DIFFERENTIAL  X X X X X X X X X   x x x x    X   x x x x 
TYPE      SSN        SSN                  DELTA X               SIGMA X
(F)                                       (METERS)              (METERS)  


28                         40 41         45  46                         58  59         63
Ŀ Ŀ Ŀ Ŀ  Ŀ Ŀ  Ŀ Ŀ    
 . .  .  .
 X X X X X X X X X   x x x x   X   x x x x    X X X X X X X X X   x x x x    X   x x x x  
             DELTA Y             SIGMA Y                  DELTA Z              SIGMA Z
             (METERS)            (METERS)                 (METERS)             (METERS)


64       65    66       70   71    72       76     77  80
Ŀ      Ŀ   Ŀ   Ŀ   Ŀ     Ŀ       
                    
REJECT  ORIG    D D D Y S    DIFF   D D D Y S       BLANK
CODE    INST    ORIGIN DAY   INST  DIFFERENTIAL 
        CODE    IDENTIFIER   CODE   IDENTIFIER















                                            N-13COORDINATE RECORD (Optional)

                                                       
 1        2    3    4 5    6     9   10   11     14  15   16       20   21  
Ŀ      Ŀ  Ŀ  Ŀ  Ŀ  Ŀ  Ŀ  Ŀ  Ŀ  Ŀ
                      
RECORD  BLANK  K   BLANK   STATION  BLANK   SHORT   BLANK COORDINATE  BLANK
TYPE         (0,1)         SERIAL           NAME          FRAME
(G)                        NUMBER                         DESIGNATOR
                                       

22                       33  34    35                       46  47
Ŀ Ŀ  Ŀ   Ŀ Ŀ  Ŀ
.     .  
 X X X X X X X X   x x x x  BLANK   Y Y Y Y Y Y Y Y   y y y y  BLANK
   X COORDINATE  (METERS)             Y COORDINATE  (METERS)
                   

48                       59  60   61       64  65   66       69  70   71       74  75 80
Ŀ Ŀ  Ŀ  Ŀ Ŀ  Ŀ  Ŀ Ŀ  Ŀ  Ŀ Ŀ  Ŀ
.    .    .    .  
 Z Z Z Z Z Z Z Z   z z z z  BLANK   SIGMA X   BLANK   SIGMA Y   BLANK   SIGMA Z    BLANK
    Z COORDINATE  (METERS)          (METERS)          (METERS)          (METERS)
















                                            N-14STATION INFORMATION RECORD
                                                                                             
          
 1      2     5   6     9    10 11   12 13   14 15   16 17   18         23
Ŀ    Ŀ Ŀ   Ŀ   Ŀ   Ŀ   Ŀ   Ŀ
                    
RECORD  STATION    FOUR       EXT.    MET.   TIME     ION.      SOLUTION
TYPE    SERIAL   CHARACTER    FREQ.   USE    PARAM.   USE         TYPE
(H)     NUMBER   IDENTIFIER   CODE    CODE   CODE     CODE


24                                                                           78
Ŀ

     COMMENT FIELD                                                          

79 80
Ŀ

BLANK




















                                            N-15
                          G-FILE EXAMPLES


Below are fragments from six independent, simulated GPS Data
Transfer Format files (G-FILEs).  There is one Project record (A)
per G-file.  Each session vector set, or individually computed
vector in a multi-receiver session, requires a Session Record (B). 
Each vector requires at least one Vector Record (C) or Long Vector
Record (F).  Vector Records with Coordinate Records must follow
the same Session Record.  Station Information (H) Records are
required as circumstances dictate and may be optionally added
where not required.  These records must be followed by sufficient
Correlation (D) or Covariance Records (E) to express all
off-diagonal correlation or covariance terms in the matrix half
provided from the session computation.  Correlation and Covariance
Records may not be intermixed.


1.  Project (A), Session (B), Vector (C), and Correlation (D)
records for a single vector between two stations in a two receiver
session or individually computed vector in a multi-receiver
session.


AKS1989061619890810
B19890622210419890623003201OMNI21JUL89    BDCST200040101025NGS   
19890919L1DDFX
C02860255   22818804  691  517712752 1665  621497962 1259
M1739APACIM1739AK60A
D  1  2 -1507832  1  3 -1653265  2  3 -9400487


2.  Project (A), Session (B), Vector (C), and Correlation (D)
records for a
three-receiver (two vector) session computed simultaneously in
session mode.


AA21989061619890810
B198907191920198907192022020MNI21JUL89    NSWC  200020202026NGS  
19891010IFDDFL
C02520251    2090836   21    3595939   80    5412122   45
T1735BTOLPT1735BIO35
C02520250  -42878920   42  -19024426   93  -28455946   69
T1735BTOLP71735BIO17
D  1  2 -3449463  1  3  -169254  1  4 -7443040  1  5 -3452654  1  6 
1753975
D  2  3 -7698120  2  4 -6329835  2  5  1258498  2  6  8573493  3 
4 -6485385
D  3  5 -6084380  3  6  -477478  4  5 -6124087  4  6 -3864367  5  6 
8630812


Note: If a multi-receiver session is computed as if all possible
vectors are independent, then there would be Session, Vector, and
Correlation records for each vector in the session.  Thus, the
record sequence would be A, B, C, D, B, C, D, B, C, D, etc.  The
Session records would be nearly identical to the multi-receiver
example except that start and stop times could vary with each
vector.  The number of vectors indicated on each Session Record
would be one, i.e., there would be a Session Record for each vector
and the cross correlation terms between vectors would not exist.







                                N-163.  Project (A), Session (B), Vector (C), and Correlation (D)
Records for a five-receiver (four vector) session computed
simultaneously in session mode.


AW11989061619890810
B19890718192419890718225204OMNI21JUL89    BDCST 200020202025NGS  
19891003L1DDFL
C03000287    5764741   77    1459095   44    2345097   54
R1765ASMILR1765ANEOP
C03000223  -52521873   47    -229406  101   -1142670   75
R1765ASMILR1765ACESZ
C03000305  -42878920   42  -19024426   93  -28455945   69
R1765ASMILR1765AX042
C03000240    7097171   69   -1171456   40   -1443438   46
R1765ASMILR1765AG042
D  1  2 -7621157  1  3 -6268111  1  4  1032188  1  5 -7397468  1  6 
2749723
D  1  7 -7716473  1  8 -6339150  1  9  1294594  1 10 -2396473  1
11 -2753742
D  1 12 -5804898  2  3  -791184  2  4 -6108347  2  5 -1739462  2  6 
9010327
D  2  7 -7729301  2  8 -6463718  2  9  1526641  2 10 -3826492  2 11 
3610736
D  2 12 -6449538  3  4   170894  3  5 -6299216  3  6 -1003847  3 
7 -5307149
D  3  8 -7680811  3  9 -6477668  3 10  1506536  3 11 -9537262  3
12 -1836426
D  4  5 -6154878  4  6  -248020  4  7 -6087715  4  8 -1633847  4  9 
6354725
D  4 10 -7804602  4 11 -6047825  4 12  1262026  5  6  3746287  5 
7 -7243634
D  5  8 -6110139  5  9  -321344  5 10 -6165227  5 11  8362528  5 12 
9162533
D  6  7 -5971690  6  8  -516393  6  9 -6136978  6 10 -9354622  6 11 
1535474
D  6 12 -5920223  7  8  -559594  7  9 -6153794  7 10  2645373  7
11 -5373742
D  7 12 -5527744  8  9 -7793107  8 10  1043462  8 11  5378213  8
12 -2564522
D  9 10 -5371777  9 11 -7908942  9 12  1046883 10 11  8354256 10
12 -3372634
D 11 12  7153372


4.  Project (A), Session (B), Vector (C), and Covariance (E) Records
for a
three-receiver (two vector) session computed simultaneously in
session mode.


AC51989061619890810
B198907191920198907192022020MNI21JUL89    NSWC  200020202026NGS  
19891010WLDDPF
C02520251    2090836   21    3595939   80    5412122   45
T1735BTOLPT1735BIO35
C02520250  -42878920   42  -19024426   93  -28455946   69
T1735BTOLPT1735BIO17
E  1  2    -3449231  1  3      169013  1  4    -7443219  1  5    -
3452017
E  1  6    -1753648  2  3     7698884  2  4    -6329438  2  5    
1258689
E  2  6     8573027  3  4    -6485903  3  5    -6084227  3  6     -
477369
E  4  5     6124824  4  6    -3864711  5  6     8630682


5.  Project (A), Session (B), Long Vector (F), and Correlation (D)
Records for a three-receiver (two vector) session computed
simultaneously in session mode.


AM31989061619890810
B199003121920199003122022030MNI21JUL89    NSWC  200050202027NGS 
19900605IFDDPF
F02520251  -7398138095   62   -611028070  140   -759539795   81
R0710AR0710A
F02520210 -28097365450    2   6537703840    2   1612488880    2
R0710AR0710A   
D  1  2 -3449463  1  3  -169254  1  4 -7443040  1  5 -3452654  1  6 
1753975
D  2  3 -7698120  2  4 -6329835  2  5  1258498  2  6  8573493  3 
4 -6485385
D  3  5 -6084380  3  6  -477478  4  5 -6124087  4  6 -3864367  5  6 
8630812





                                N-176.  Project (A), Session (B), Vector (C), Coordinate (G), Station
Information (H), and Correlation (D) Records for a five-receiver
session computed simultaneously.


AG41989061619890810
B19921019162019921019202204OMNI06JAN93    NGS    50090202027NGS  
19930115IFDDFX
C02520251 -121666909   30  157350726   56  117976050   41
R2932ANORDR2932ASECO  
C02520250 -418472429   32  247232117   60    8372071   44
R2932ANORDR2932ABURR  
C02520253 -553950607   35  500052515   64  221106176   48
R2932ANORDR2932AFIGU 
C02520254 -289152973   31  300310186   55  183697838   42
R2932ANORDR2932APINE
G 1  0252 NORD SIO92 -25711011350 -45925184360  35928923390  010 
010  010      
H0252NORD01020202IFDDFXREFERENCE STATION
D  1  2 -7621157  1  3 -6268111  1  4  1032188  1  5 -7397468  1  6 
2749723
D  1  7 -7716473  1  8 -6339150  1  9  1294594  1 10 -2396473  1
11 -2753742
D  1 12 -5804898  2  3  -791184  2  4 -6108347  2  5 -1739462  2  6 
9010327
D  2  7 -7729301  2  8 -6463718  2  9  1526641  2 10 -3826492  2 11 
3610736
D  2 12 -6449538  3  4   170894  3  5 -6299216  3  6 -1003847  3 
7 -5307149
D  3  8 -7680811  3  9 -6477668  3 10  1506536  3 11 -9537262  3
12 -1836426
D  4  5 -6154878  4  6  -248020  4  7 -6087715  4  8 -1633847  4  9 
6354725
D  4 10 -7804602  4 11 -6047825  4 12  1262026  5  6  3746287  5 
7 -7243634
D  5  8 -6110139  5  9  -321344  5 10 -6165227  5 11  8362528  5 12 
9162533
D  6  7 -5971690  6  8  -516393  6  9 -6136978  6 10 -9354622  6 11 
1535474
D  6 12 -5920223  7  8  -559594  7  9 -6153794  7 10  2645373  7
11 -5373742
D  7 12 -5527744  8  9 -7793107  8 10  1043462  8 11  5378213  8
12 -2564522
D  9 10 -5371777  9 11 -7908942  9 12  1046883 10 11  8354256 10
12 -3372634
D 11 12  7153372

 




























                                N-18