U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the

FEDERAL HIGHWAY ADMINISTRATION

Computer Program for Point Location And 

Calculation of ERror (PLACER)

Open-File Report 99-99

A Contribution to the

NATIONAL HIGHWAY RUNOFF DATA AND METHODOLOGY SYNTHESIS
U.S. Department of the Interior

U.S. Geological Survey

Computer Program for Point Location And 

Calculation of ERror (PLACER)

By GREGORY E. GRANATO

Open-File Report 99-99

A Contribution to the

NATIONAL HIGHWAY RUNOFF DATA AND METHODOLOGY SYNTHESIS

Prepared in cooperation with the

FEDERAL HIGHWAY ADMINISTRATION 

Northborough, Massachusetts

1999
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of trade or product names in this report is for identification 

purposes only and does not constitute endorsement by the 

U.S. Geological Survey.

For additional information write to: Copies of this report can be purchased 

Chief, Massachusetts-Rhode Island District U.S. Geological Survey

U.S. Geological Survey Information Services

Water Resources Division Box 25286

10 Bearfoot Road Denver, CO 80225-0286

Northborough, MA 01532
PREFACE

Preface 

Knowledge of the characteristics of highway runoff (concentrations and loads of 

constituents and the physical and chemical processes which produce this runoff) 

is important for decision makers, planners, and highway engineers to assess and 

mitigate possible adverse-impacts of highway runoff on the Nation’s receiving 

waters. In October, 1996, the Federal Highway Administration and the U.S. 

Geological Survey began the National Highway Runoff Data and Methodology 

Synthesis to provide a catalog of the pertinent information available; to define 

the necessary documentation to determine if data are valid (useful for intended 

purposes), current, and technically supportable; and to evaluate available 

sources in terms of current and foreseeable information needs. This paper is 

one contribution to the National Highway Runoff Data and Methodology 

Synthesis and is being made available as a U.S. Geological Survey Open-File 

Report pending its inclusion in a volume or series to be published by the Federal 

Highway Administration. More information about this project is available on the 

World Wide Web at http://ma.water.usgs.gov/fhwa/runwater.htm

Fred G. Bank

Team Leader

Natural and Cultural Resources Team

Office of Environment and Planning

Federal Highway Administration

Patricia A. Cazenas

Highway Engineer

Natural and Cultural Resources Team

Office of Environment and Planning

Federal Highway Administration

Gregory E. Granato

Hydrologist 

U.S. Geological Survey

Con

CONTENTS

Abstract .............................................................................................................................................................................

Introduction .......................................................................................................................................................................

Acknowledgments ...................................................................................................................................................

The PLACER computer program......................................................................................................................................

Installing PLACER............................................................................................................................................................

Using PLACER .................................................................................................................................................................

Manual-input method ..............................................................................................................................................

Input-file method .....................................................................................................................................................

Anatomy of an input/output file ..............................................................................................................................

Case studies .......................................................................................................................................................................

Case 1: Map coordinates .........................................................................................................................................

Case 2: Known locations.........................................................................................................................................

Summary ...........................................................................................................................................................................

References .........................................................................................................................................................................

Appendix 1: Study-site locator form.................................................................................................................................

Appendix 2: FORTRAN code for PLACER.....................................................................................................................

DISKETTE

(in pocket)

1. Computer files containing raw and executable FORTRAN code, example input/output files from the

text for the Point Locatin And Calculatin of ERror program (PLACER)

FIGURES 

1. Example of the format of an input/output file from the PLACER program ..........................................................

2. Base map of southwest Boston, Massachusetts, with a user-defined coordinate system (UDCS) scale for

example calculations using PLACER program......................................................................................................

3. Calculation of site coordinates by the PLACER program using known latitude and longitude 

 coordinates as features...........................................................................................................................................

4. Calculation of site coordinates by the PLACER program using the latitude and longitude coordinates

 of map features located using the U.S. Geological Survey Geographic Names Information System (GNIS)......

TABLES

1. Computer files containing raw and executable FORTRAN code for the 

Point Location And Calculationof ERror program (PLACER) ............................................................................
VI Contents
Introd

Abstract

A program designed for point location and 

calculation of error (PLACER) was developed as 

part of the Quality Assurance Program of the 

Federal Highway Administration/U.S. Geological 

Survey (USGS) National Data and Methodology 

Synthesis (NDAMS) review process. The 

program provides a standard method to derive 

study-site locations from site maps in highwayrunoff, urban-runoff, and other research reports. 

This report provides a guide for using PLACER, 

documents methods used to estimate study-site 

locations, documents the NDAMS Study-Site 

Locator Form, and documents the FORTRAN 

code used to implement the method.

PLACER is a simple program that calculates 

the latitude and longitude coordinates of one or 

more study sites plotted on a published map and 

estimates the uncertainty of these calculated 

coordinates. PLACER calculates the latitude and 

longitude of each study site by interpolating 

between the coordinates of known features and the 

locations of study sites using any consistent, 

linear, user-defined coordinate system. This 

program will read data entered from the computer 

keyboard and(or) from a formatted text file, and 

will write the results to the computer screen and to 

a text file. PLACER is readily transferable to 

different computers and operating systems with 

few (if any) modifications because it is written in 

standard FORTRAN. PLACER can be used to 

calculate study site locations in latitude and 

longitude, using known map coordinates or 

features that are identifiable in geographic 

information data bases such as USGS Geographic 

Names Information System, which is available on 

the World Wide Web.

INTRODUCTION

Well-defined sampling-site locations are 

necessary to document water-quality data and re

interpretations from research reports as valid, c

and technically defensible (Granato and others, 

Site-location information is critical to conduct a

assessment of available data for use on a local, 

regional, or national level. Documented inform

about study-site-sampling locations is necessary 

• permit independent evaluation of the suitabili

study sites used in a water-quality investig

• establish the repeatability of a study by ensur

ability to repeat sampling operations at the 

location at a later time; 

• establish comparability between study sites in 

of geographic, climactic, and land-use 

characteristics; and 

• assess the geographic scale of a study with m

data-collection sites through examination o

distribution of and distance between study 

To provide sufficient site information, eac

study should have a table describing each site th

includes latitude, longitude, and the estimated 

uncertainty of these measurements (ITFM, 199

1995b). Additionally, or in place of the table, ea

study should produce a site map with identifiab

locations, a defined scale, and at least two point

defined with latitude and longitude.

The latitude and longitude (LAT/LON) c

tion is a universally recognized coordinate syste

applicable to any point on the Earth. This Coor

system is not based upon any particular choice 

projection (as are many State plane coordinate 

tems), or upon a secondary classification metho

such as road-mile markers, or road survey-statio

offset. Consistent use of LAT/LON is importan

(1) for a standardized national water-quality dat

(2) to facilitate map creation; (3) for geographic 

spatial analysis; and (4) for integration with oth

geographic data sets, such as climate, census, o

land-use information. The Intergovernmental T

Computer Program for Point Location And 

Calculation of ERror (PLACER)

By Gregory E. Granato
2 Computer Program for Point Location And Calculation of ERror (PLACER)

Force on Monitoring Water Quality (ITFM) defined 

sampling location as one of the minimum set of 

required metadata standards, and identified LAT/LON 

as the standard site location coordinate system (ITFM, 

1995a, 1995b).

Review of over 200 published studies of 

highway and urban runoff indicate that this information 

is often not available, even when location tables and 

maps are included in report documentation. Therefore, 

a method was needed to facilitate and standardize the 

process used to determine study-site locations in 

LAT/LON coordinates. The program Point Location 

and Calculation of ERror (PLACER) reads input 

entered from the keyboard or from an input file, 

interpolates the coordinates of study sites in relation to 

known features, and documents results in an output 

file. The program is designed to interpolate the latitude 

and longitude of study sites plotted on published base 

maps when their coordinates are not provided. 

PLACER was developed as part of the Quality 

Assurance Program of the Federal Highway 

Administration (FHWA)/U.S. Geological Survey 

(USGS) National Data and Methodology Synthesis 

(NDAMS) review process to provide a standard 

method to derive study site locations. Standard 

methods designed to minimize the possibilities for 

error are important for the management, assessment, 

and validation of project data (Jones, 1998). The 

PLACER software application provides the user with 

a standard method for consistently calculating a 

unique latitude and longitude for a point, such as a 

study-site location that is plotted on a map, as well 

as for determining the uncertainty in the calculated 

position. When used with a report’s base map and 

the study-site locator form (appendix 1), PLACER 

provides a documentable process that reduces or 

eliminates the potential for human error in 

interpolating site coordinates from published site maps. 

PLACER creates an output file that documents input 

data and results of the calculations. The information 

documented in the output file can be checked manually 

or by rerunning the program using this record as an 

input file. Automation of the simple, but tedious and 

error-prone interpolation process facilitates quality 

assurance and quality control of the site-location values 

calculated for the NDAMS bibliographic data base. 

This report provides a guide for the use of 

PLACER, documents the methods used to estimate 

study-site locations, documents the NDAMS Study 

Site Locator Form (appendix 1), and document

FORTRAN code (appendix 2) used to impleme

method. The report provides information about 

computer program, installation of the program 

distribution media (such as floppy disk or CD-R

instructions for using PLACER, and case studie

illustrate use of the program.

Acknowledgments

The author gratefully acknowledges inpu

Berwyn Jones and Shannon Dionne of the U.S. 

Geological Survey and Patricia Cazenas of the 

Highway Administration for reviews and feedba

improved both the program and the documentat

the PLACER program. George Z. Hornberger o

U.S. Geological Survey was helpful in compilin

code and testing the program on the Macintosh 

computer platform.

THE PLACER PROGRAM

PLACER is used to determine the LAT/LO

point plotted on a map and to estimate the unce

of the LAT/LON coordinates calculated using i

data. The program may be used to estimate stu

locations from LAT/LON tick marks on a base m

from known locations featured on a published m

Known locations may be features that can be lo

on a published map, or feature locations that ca

determined using a national atlas, or informatio

services, such as the USGS Geographic Names 

Information System (GNIS) data base (USGS, 

1998b), the National Imagery and Mapping Ag

(NIMA) GEOnet Names Server data base (NIM

1998), or the Natural Resources Canada (NRC) 

Canadian Geographic Names Server (Natural 

Resources Canada, 1998) available through the 

Wide Web. PLACER interpolates between thes

known points—referred to as features—and the 

unknown location of data-collection points—re

to as sites, using any arbitrary (but consistent an

linear) user-defined coordinate system (UDCS)

PLACER also provides an estimate of the uncer

in each calculated location as an indication of d

quality.
Installing PL

The accuracy and precision needed to locate a 

given study site depends upon study objectives. If the 

objectives are to verify results or to detect changes or 

trends in measured water quality by repeating a 

sampling effort, then sites must be located precisely—

within a few feet (tenths of a second). If the sampling 

site is well documented and(or) is located at a 

recognizable landmark—so that the precise sampling 

point could be easily recognized from a distance—then 

the location may be specified within hundreds of feet (a 

few seconds). The minimum symbol size for a site 

plotted on an 11-by-8.5-inch map of the conterminous 

United States has a radius of about 50 miles (about 40 

minutes). Therefore, accuracies within 5 to 20 miles 

(about 4 to 18 minutes) may be acceptable for grouping 

sites by region for statistical interpretation, or for 

mapping on a national or regional scale.

To establish a relation between the LAT/LON 

coordinates of known locations—map features—and 

the UDCS, at least two known locations are required. 

The intersection of lines of latitude and longitude from 

these two locations, or potentially the location of a 

third map feature, is then used to establish the origin. 

The Y and X locations for the origin and each feature 

with respective latitude and longitude values are 

defined using any measurement scale (the UDCS). The 

standard LAT/LON coordinate expression of degrees, 

minutes, and seconds is then converted to a total 

number of seconds to facilitate calculations. The 

program then reads the location of each site in the 

UDCS.

PLACER will read data from the computer 

keyboard and(or) a formatted text file, and will write 

results to the computer screen and to an ASCII 

(American Standard Code for Information Interchange) 

text file. PLACER is currently configured to accept up 

to 21 features and 21 sites. The user can define the 

desired number of features and sites using the 

keyboard/screen or input-file interface. If the user 

needs more features or sites, the FORTRAN code 

(appendix 2) can be modified to accept more. During 

the review of more than 200 reports relevant to 

highway and urban runoff for the USGS-FHWA 

NDAMS study, however, there was rarely a need for 

more than about 10 features or sites.

Once the input of all necessary data is complete, 

PLACER calculates and records: 

1. the ratio of the distances in terms of LAT/L

UDCS map units (seconds per measured 

for each map feature, 

2. the average and the standard deviation for 

population of coordinate ratios, 

3. the LAT/LON coordinate for each site as t

product of the Y and X coordinates of e

and the average ratios of the feature 

population’s latitude and longitude coord

respectively, and 

4. the standard deviation of the population of 

nonzero coordinate-ratios. 

The standard deviations may be used to e

the uncertainty or error of the interpolation proc

Only features with nonzero coordinates are use

calculations to avoid division-by-zero errors. T

calculated standard deviations indicate potentia

problems in the input data and(or) indicate the 

uncertainty of the estimated site-location coord

The location of features that differ significantly 

the average should be investigated for measurem

error, a faulty LAT/LON coordinate, and(or) the 

a map with an axis orientation that differs signi

from a true North-South axis. 

PLACER prints the input values and the 

calculated results to the screen and to a user-spe

output file for documentation, review, and asses

The ratio of LAT/LON to UDCS coordinate val

each feature should be compared to the average 

standard deviation of these ratios to assess each 

If an outlier in the ratios indicates that an input 

occurred, the output file can be corrected using 

ASCII-compatible text editor, and PLACER can 

rerun using the corrected file as an input file.

INSTALLING PLACER

The PLACER code is readily transferable 

among different computers and operating system

with little if any modifications because it is wri

standard FORTRAN. The original FORTRAN 

(appendix 1) and several runtime versions (tabl

provided on the disk for ease of installation. Th

FORTRAN code and executable versions are av

on disk for DOS/Windows, Macintosh OS pers

computer (PC) operating systems, and Data Ge

Unix.
4 Computer Program for Point Location And Calculation of ERror (PLACER)

PLACER is a simple program without a graphic 

user interface, so that almost any available computer 

and operating system should be able to run this code. 

PLACER can be run from the installation disk, but it is 

preferable to run the program from a designated 

directory on a local hard disk or an equivalent device 

with read and write capabilities. The successful 

operation of PLACER requires the following: 

• the executable version of the PLACER code must be 

compiled under the same operating system as the 

computer being used to run program (for 

example, the personal computer version can be 

run under DOS 2.0 or higher and Windows 3.0 or 

higher), and 

• the program must be run on a disk/directory that has 

enough accessible memory to be able to hold the 

executable version and at least one small text file 

(about 60 kilobytes (KB) for DOS/Windows, 

about 170 KB for Macintosh PCs, and about 180 

KB for Data General Unix). 

Specific instructions for loading and 

implementing PLACER are machine dependent. 

Generally, the proper executable file should be loaded 

in a new directory. To use PLACER on a computer 

system that is not listed in table 1, it will be necessary 

to create a machine-specific executable code. To do 

this, users must have a FORTRAN compiler that is 

suitable for their computer and operating systems. 

USING PLACER

The PLACER process includes the definition of 

known features, the location of sites of interest, and the 

calculation of results by establishing LAT/LON 

coordinates for each site. To implement the PLACER 

process the user: 

1. establishes axes that are aligned as closely as 

possible with the lines of latitude and 

longitude, 

2. measures the coordinates of each feature l

(in LAT/LON and the UDCS) and record

values along with other documentation 

NDAMS study site locator form, 

3. measures the coordinates of sites of intere

the UDCS) and records these positions 

NDAMS study site locator form, and 

4. inputs the location data for features and si

manually or by use of an appropriate inp

and the PLACER program,

5. interpolates the position of the sites of inte

LAT/LON coordinates) from the inform

about the relative locations (in UDCS 

coordinates) of features (of known LAT

coordinates) and sites, 

6. presents the user with input values and the 

of calculations, by writing input and ou

the screen, and 

7. documents the information by writing inp

output to a text file. 

PLACER is started using the standard me

initiate a program in each operating system. Fo

example, the executable file name is typed on th

command line in DOS or Unix systems, and the 

program-file icon is activated by the mouse in 

Windows and Macintosh systems. If the file is 

activated from a CD-ROM or from another read

memory location, the input and output file nam

contain the full path name of a drive and directo

where the user can save files. File names can b

60 characters long, including the drive and the 

directory specification, although the actual file 

should not exceed the "8.3" configuration of sta

DOS files if these files are to be fully compatibl

systems.

PLACER’s user interface is structured to 

in a linear manner. When the program is started

introductory screen comes up with brief instruc

and three choices. The initial choices are data e

through (1) manual input or (2) an input file. T

Table 1. Computer files containing raw and executable FORTRAN code for PLACER—the Point Location And Calcula

ERror program.

Filename Platform Compiler

PLACERv2.for Not specific Uncompliled FORTRAN code (Appendix 2)

PLACERv2.out Data General Unix Green Hills FORTRAN compiler (Green Hills Software Inc., 1990)

PLACERv2.exe MS-DOS, or MS-Windows Microsoft FORTRAN compiler version 5 (Microsoft Corporation, 1989)

PLACERv2.bin Macintosh OS Metrowerks Code Warrior MPW version 3.4.2 (Metrowerks Corporporation
Using PL

menu also allows the user to exit immediately in case 

of accidental activation of the PLACER program. The 

manual entry choice prompts a series of menus that 

lead the user through the process. The input file choice 

is programmed to skip manual entry and read all values 

from the input file specified by the user. Compared to 

commercial programs, the input structure is relatively 

primitive and somewhat unforgiving, because the 

potential uses of the program did not justify an 

extensive user interface development process. The 

program, however, was written with some internal 

data-checking logic and opportunities for the user to 

reenter information when mistakes are detected. The 

manual data-entry process is not trivial when there are 

more than a few features and sites. Therefore, 

unrecoverable mistakes in the input data set are most 

easily corrected by editing the output file using a 

nonformatting text editor. The user can then run this 

corrected version through PLACER as an input file to 

generate the final output.

Data entry by keyboard or input file is 

constrained by the input/output features of FORTRAN, 

and screen entry behaves slightly differently from datafile entry. Data-file entry requires that each line and 

each character of the input file follow fixed formats. 

Keyboard entry is also constrained by fixed formats. 

When UDCS values are entered, a decimal point in the 

appropriate space is mandatory. If the value "1" is 

entered, the program will read "0.01", but if a "1." is 

entered, "1.00" will be read. The minimum UDCS 

value is 0.01, and the maximum is 9,999,999 (entered 

without commas as "9999999."). at the screen prompt. 

Any internally consistent units for measuring length 

can be used because the LAT/LON coordinates of each 

site is calculated using the average ratios of latitude 

and longitude to the UDCS values.

The LAT/LON values entered into the program 

are dependent upon the location and the characteristics 

of the LAT/LON coordinate system. Latitude is 

measured in degrees (D), minutes (M), and seconds 

(S), increasing from zero degrees at the equator to 90 

degrees at each pole. Therefore, latitude is entered in 

the format DDMMSS and the program is designed to 

register a positive measurement along the Y axes from 

south to north (bottom to top) as an increase in latitude. 

Longitude is also measured in degrees, minutes, and 

seconds, increasing from zero degrees at the prime 

meridian, which passes through Greenwich, England, 

westward and eastward, to 180 degrees located in the 

Pacific Ocean. Therefore, longitude is entered in the 

format DDDMMSS and the program is designe

register a positive measurement along the X axe

west to east (left to right) as a decrease in longi

This system is appropriate for all of North Amer

Hawaii. PLACER can be applied to locations i

hemisphere as long as the orientation of UDCS 

constantly and appropriately aligned. The latitu

longitude inputs are read by PLACER from left 

right, so it is important to add any leading zeroe

manual input or the program will misinterpret th

when degrees and minutes are converted to seco

the calculations.

Input values of minutes and seconds can 

greater than or equal to 60 as long as the conver

to seconds will yield the proper input values for 

calculations in seconds. For example, a value o

minutes is equivalent to 1 degree and 39 minute

of which are calculated as 5940 seconds. Input 

coordinates for features are output in the same f

as entered by the user. Output coordinates for si

however, are in the format of degrees, minutes, 

seconds. These format differences become app

when a subset of feature locations are also inpu

as sites (to check the accuracy and precision of 

calculations). For example, the LAT/LON coor

for a feature (that is also used a check site) ente

99 minutes would be written as "009900" with 

feature-coordinate data, and "013900" (1 degree 

minutes) with the site-coordinate data. The inp

is not reformatted by PLACER because reform

may obscure data entry errors.

PLACER was designed with the assumpt

the ratio of latitude and longitude to the Y and X 

measurements, respectively, would be constant 

small local site-maps used to locate study areas

conditions would violate this design assumption

first condition would be the placement of the U

axes on a site map that are not oriented with the 

LAT/LON axes. This condition, if it introduces 

substantial bias, will be reflected in the standard 

deviation of the ratio of the LAT/LON to UDCS 

measurements and in the calculated LAT/LON 

coordinates of features that are also input as site

check the calculations. Tests indicate that as lo

the user locates features beyond the farthest site

each axis, these outlying features will affect the 

calculated average and standard deviation so th

reported LAT/LON and associated uncertainty 

encompass the true location of the site. A map 

projection is the method used to portray all or p
6 Computer Program for Point Location And Calculation of ERror (PLACER)

the spherical earth on a flat surface. The second 

condition that violates the assumption of a linear 

relation between the LAT/LON and UDCS values 

occurs on maps covering large areas where distortions 

are caused by the projection of the base map. The 

effect of distortions in the relation between the 

LAT/LON and measured units depends on latitude 

(because the lines of longitude converge at the poles), 

the projection method used, and the areal extent of the 

map. Again, however, well-placed features will 

account for this error, which will be reflected in the 

calculated average and standard deviation in the 

relation between the LAT/LON and measurement 

units. 

Manual-Input Method

Once PLACER has been activated and the 

manual-input feature has been chosen for data entry, 

the user will be prompted for detailed information. 

The program requires the output-file name, the map 

name, the number of features, the number of sites, the 

LAT/LON of the origin, the LAT/LON of map features, 

the Y/X coordinates of the map features, and (since the 

LAT/LON of sites is unknown) the Y/X coordinates of 

the sites. After the introductory information is entered 

and after each feature and site is entered, PLACER 

initiates an input-data check. If the user enters the 

value "0" or executes a carriage return on the input-data 

check line, then the program progresses to the next 

task. If the user enters the value "1", to indicate an 

error in the data as entered, then all the data in the 

previous section must be reentered. The user must 

complete the entire data entry process to create an 

output file. The program is relatively robust, but 

cannot accept nonalphanumeric input. Once data entry 

is complete, the program calculates the necessary 

information and writes the input data and the results of 

the calculations to the screen and to the output file.

Input-File Method

Once PLACER has been activated and the inputfile feature chosen for data entry, the user will be 

prompted for the file name. An input file is created (as 

an output file of a previous program execution) when 

the manual-input method is used to enter data. These 

files can be modified for further use using a text 

A user could also create an input file using a tex

but the file would have to conform to the relativ

strict FORTRAN input format structure as defin

the format statements in the program code (app

3). In the input-file mode, PLACER requires th

to enter both the input and output file names an

all the remaining information from the input fil

program has an internal check and feedback loo

ensure that the user does not accidently destroy 

input file so input and output file names cannot 

same. Once the file name information has been 

correctly, the program reads the input file and 

calculates the necessary information. The prog

then writes the input data and the results of the 

calculations to the screen and to the output file. 

using the input-file method, the program reads o

those values that would be entered when using 

manual method. Therefore, only revisions to fe

and site names, the LAT/LON and Y/X coordin

features, and the Y/X coordinates of sites are re

used. Features and(or) sites may be added to or 

from an input file (following the proper formats

appropriate number of features and sites is ente

the correct line at the top of the file.

Anatomy of an Input/Output File

The Input/Output (I/O) file structure is ar

sequentially to facilitate manual and automated 

management, assessment, and validation of site

location metadata by the operator and by PLAC

Figure 1 is an annotated example of an I/O file 

by PLACER. The basic information is at the he

the file (fig. 1). The number of features and the n

of study sites indicate to PLACER, or to a perso

reading the file, how many sites and locations a

expected. Each line of feature data provides the 

data as well as the LAT/LON coordinates in tot

seconds (fig. 1). Each line of site data provides 

the input data (UCDS measurements) and the o

data (LAT/LON coordinates in degrees, minute

seconds and in total seconds). The I/O file docu

the ratio of latitude and longitude to the Y and X 

values, respectively. The I/O file also documen

differences in LAT/LON (in seconds) and in Y/

UDCS values from each respective user-defined 
Using PL

INPUT FILENAME: IOFile.txt

 MAP NAME: USGS QUAD Boston South, MA BASIC INFORMATION

 NUMBER OF MAP FEATURES: 8

 NUMBER OF STUDY SITES: 4

 OUTPUT FEATURE DDDMMSS SSSSSSSS X OR Y

 Lat & y: Map Origin at SW 0421500 152100 0.00

 Lon & x: Map Origin at SW 0710300 255780 0.00

 Lat & y: Known Coord2 0421500 152100 0.00

 Lon & x: Known Coord2 0710000 255600 4.80

 Lat & y: Known Coord3 0421800 152280 4.80

 Lon & x: Known Coord3 0710000 255600 4.80

 Lat & y: Known Coord4 0421800 152280 4.80 FEATURE

 Lon & x: Known Coord4 0710300 255780 0.00 DATA

 Lat & y: Thimble Island(GNIS) 0421827 152307 5.50

 Lon & x: Thimble Island(GNIS) 0710128 255688 2.45

 Lat & y: Savin Hill (GNIS) 0421838 152318 5.80

 Lon & x: Savin Hill (GNIS) 0710300 255780 0.00

 Lat & y: Forbes Hill (GNIS) 0421525 152125 0.65

 Lon & x: Forbes Hill (GNIS) 0710142 255702 2.10

 Lat & y: Halftide Rock (GNIS) 0421818 152298 5.30

 Lon & x: Halftide Rock (GNIS) 0710142 255702 2.20

 Lat & y: Norfolk Downs (GNIS) 0421620 152180 2.15

 Lon & x: Norfolk Downs (GNIS) 0710115 255675 2.80

 **********************************************************************

 OUTPUT SITE DDDMMSS SSSSSSSS X OR Y

 Lat & y: Tenean Beach Drain 0421736 152256 4.15

 Lon & x: Tenean Beach Drain 0710241 255761 0.52

 Lat & y: Interchange 20 Drain 0421709 152229 3.45 SITE

 Lon & x: Interchange 20 Drain 0710235 255755 0.70 DATA

 Lat & y: Known Coord3 0421800 152280 4.80

 Lon & x: Known Coord3 0710002 255602 4.80

 Lat & y: Norfolk Downs (GNIS) 0421620 152180 2.15

 Lon & x: Norfolk Downs (GNIS) 0710117 255677 2.80

 **********************************************************************

 FEATURE VALUES DLAT/DY DLAT DY

 Known Coord2 0.00 0 0.00 LATITUDE

 Known Coord3 37.50 180 4.80 CALCULATION

 Known Coord4 37.50 180 4.80 RESULTS

 Thimble Island (GNIS) 37.64 207 5.50

 Savin Hill (GNIS) 37.59 218 5.80

 Forbes Hill (GNIS) 38.46 25 0.65

 Halftide Rock (GNIS) 37.36 198 5.30

 Norfolk Downs (GNIS) 37.21 80 2.15

 **********************************************************************

 LAT AVG & STD DEV (SD): AVERAGE SD 2 X SD 3 X SD

 37.61 0.40 0.81 1.21

 **********************************************************************

 FEATURE VALUES DLON/DX DLON DX

 Known Coord2 -37.50 -180 4.80 LONGITUDE

 Known Coord3 -37.50 -180 4.80 CALCULATION

 Known Coord4 0.00 0 0.00 RESULTS

 Thimble Island (GNIS) -37.55 -92 2.45

 Savin Hill (GNIS) 0.00 0 0.00

 Forbes Hill (GNIS) -37.14 -78 2.10

 Halftide Rock (GNIS) -35.45 -78 2.20

 Norfolk Downs (GNIS) -37.50 -105 2.80

 **********************************************************************

 LON AVG & STD DEV (SD): AVERAGE SD 2 X SD 3 X SD

 -37.11 0.82 1.65 2.47

 **********************************************************************

Figure 1. Example of the format of an input/output file from the PLACER program.
8 Computer Program for Point Location And Calculation of ERror (PLACER)

Points along the axis are set to zero by the program and 

are not used in calculating the average and standard 

deviation. Examination of the average and the standard 

deviation, as well as any individual outliers in the 

results of the calculations, will identify any individual 

sources of uncertainty. If the features were entered 

correctly by the person using PLACER, the standard 

deviation will indicate the uncertainty for locations that 

can be determined from a given base map.

CASE STUDIES

Two case studies are provided to illustrate the 

use of and operation of PLACER with different types 

of data from a base map. Two hypothetical sites along 

Interstate 93 in Boston, Massachusetts, were plotted 

and located using PLACER. The two sites, shown as 

filled circles on figure 2, are a hypothetical Tenean 

Beach Drain and a hypothetical Interchange 20 Drain. 

In the first case study, known coordinates of latitude 

and longitude from the base map are used, and in the 

second case study (used to illustrate an example in 

which the coordinates are not plotted on the map), the 

latitude and longitude of the feature locations are 

derived from the USGS GNIS data base (U.S. 

Geological Survey, 1998a, 1998b).

Case 1: Map Coordinates

If at least two points of known latitude and 

longitude are included on the site map available in a 

report of investigations, then the position of any point 

on the map can be determined by interpolation using 

PLACER. The LAT/LON coordinates and the Y and X 

UDCS locations of the intersections of each LAT/LON 

axis can be input to derive the location of each study 

site on the base map. All that is needed to interpolate 

the site locations using PLACER is the origin point, 

one intersection of known LAT/LON, and another 

point that is off the axis of the origin. However, use of 

more than two LAT/LON coordinates is preferable 

because additional features provide points for check 

measurements that indicate the degree to which the 

area inscribed by the features is out of square. The 

map area can be out of square because of photocopy 

distortions, map projection, or high latitude. 

In this example, the latitude and longitud

two hypothetical study sites along Interstate 93 

Boston, Massachusetts, are located using map f

defined by known LAT/LON coordinates from 

map (fig. 2). The four known coordinates, show

bold crosses on figure 2, are listed as the "Origi

"Known Coord. #2" through "Known Coord. #4

the I/O file shown in figure 3. The known coord

for these features were recorded and entered via 

manual input. For these features, the average n

of seconds per measurement unit were 37.90 an

37.50 for latitude and longitude, respectively. T

numbers are then used to calculate the LAT/LO

coordinates of each site.

If, (1) the base map has been made prope

sites of interest are not in high latitudes, and (3) 

have been no distortions or measurement errors

standard deviation of this average should be zer

because the exact locations of the features are k

A small error in the estimate for the Y coordina

intentionally introduced for demonstration on o

the features (fig. 3). This error appears in the 

calculated standard deviations and in the calcul

latitude of the site "Known Coord. #4" which w

entered as a check measurement. The latitude a

longitude of each site was recorded in the I/O fi

uncertainty in the site-location coordinates can 

estimated by using the product of the largest va

the user-defined map units in the I/O file and tw

calculated standard deviation (theoretically, inc

about 95 percent of the population of feature lo

coordinates). For this example, the estimated 

uncertainty in the site coordinates of the data se

about plus or minus one second, if the sites are 

properly located and the symbol size is smaller 

second.

Case 2: Known Locations

To be complete, a project site map should 

include (1) a small outline map to place the stud

area within the boundaries of a recognizable 

geographic unit such as a State map, (2) a scale

(3) a North Arrow, and (4) a defined coordinate 

system (such as LAT/LON) clearly marked upo

margins (Hansen, 1991). Each of these features 

apparent on figure 2, but we will, for the purpose 

case study, assume that these marks are not ava
Case S

71 ̊03' 71 ̊01'30" 71 ̊

42 ̊18'

42 ̊16'30"

42 ̊15'

Halftide Rock

Thimble 

 Island

Savin

 Hill

Norfolk Downs

Forbes

 Hill

Known coord. #2

ORIGIN

Interchange

Tenean

 Beach

#20 Drain

Known coord. #4 Known coord. #3

Rt 3A

I-93

I-93

Rt 3

DORCHESTER

BAY

QUINCY

BAY

MILTON QUINCY

BOSTON

BOSTON

Study Area

Massachusetts

0 kilometers 0.5 1.0 1.5

Base from MassGIS 

State base map, 1:24000, 1989

Based on Massachusetts coordinate system

0 1.0 1.5

User-defined coordinate system

Figure 2. Base map of southwest Boston, Massachusetts, with a user-defined coordinate system (UDCS) scale fo

example calculations using PLACER program. 
10 Computer Program for Point Location And Calculation of ERror (PLACER)

INPUT FILENAME: Sample1.txt

 MAP NAME: USGS QUAD Boston South, MA

 NUMBER OF MAP FEATURES: 3

 NUMBER OF STUDY SITES: 4

 OUTPUT FEATURE DDDMMSS SSSSSSSS X OR Y

 Lat & y: Map Origin at SW 0421500 152100 0.00

 Lon & x: Map Origin at SW 0710300 255780 0.00

 Lat & y: Known Coord2 0421500 152100 0.00

 Lon & x: Known Coord2 0710000 255600 4.80

 Lat & y: Known Coord3 0421800 152280 4.80

 Lon & x: Known Coord3 0710000 255600 4.80

 Lat & y: Known Coord4 0421800 152280 4.70

 Lon & x: Known Coord4 0710300 255780 0.00

**********************************************************************

 OUTPUT SITE DDDMMSS SSSSSSSS X OR Y

 Lat & y: Tenean Beach Drain 0421737 152257 4.15

 Lon & x: Tenean Beach Drain 0710241 255761 0.52

 Lat & y: Interchange 20 Drain 0421710 152230 3.45

 Lon & x: Interchange 20 Drain 0710234 255754 0.70

 Lat & y: Known Coord3 0421801 152281 4.80

 Lon & x: Known Coord3 0710000 255600 4.80

 Lat & y: Norfolk Downs (GNIS) 0421621 152181 2.15

 Lon & x: Norfolk Downs (GNIS) 0710115 255675 2.80

**********************************************************************

 FEATURE VALUES DLAT/DY DLAT DY

 Known Coord2 0.00 0 0.00

 Known Coord3 37.50 180 4.80

 Known Coord4 38.30 180 4.70

**********************************************************************

 LAT AVG & STD DEV (SD): AVERAGE SD 2 X SD 3 X SD

 37.90 0.56 1.13 1.69

**********************************************************************

 FEATURE VALUES DLON/DX DLON DX

 Known Coord2 -37.50 -180 4.80

 Known Coord3 -37.50 -180 4.80

 Known Coord4 0.00 0 0.00

**********************************************************************

 LON AVG & STD DEV (SD): AVERAGE SD 2 X SD 3 X SD

 -37.50 0.00 0.00 0.00

**********************************************************************

Figure 3. Calculation of site coordinates by the PLACER program using known latitude and longitude 

coordinates as features. 
Case Stu

The NDAMS report review process revealed that most 

reports published outside of the USGS do not include 

site maps and many of the site maps that were available 

did not meet these basic mapping standards. 

Therefore, the latitudes and longitudes were more 

difficult to determine. When site maps had features 

that were identifiable using the USGS GNIS data base 

or other similar sources (USGS, 1998a, 1998b; NIMA, 

1998; Natural Resources Canada, 1998), however, site 

locations could be estimated using these features.

The USGS GNIS data base contains LAT/LON 

information for almost 2 million known places, 

features (except roads and highways), and areas in the 

United States that are identifiable by a proper name 

(USGS, 1998a, 1998b). This location information was 

digitized during the period from 1978 to 1986 from 

1:24,000-scale, 1:62,500-scale, and 1:250,000-scale 

maps, depending upon the availability of published 

maps for a given area (USGS, 1998a, 1998b). Point 

locations such as hilltops, geographic features, and 

schools can easily be identified. However, the digitized 

location of populated places (such as towns) was set at 

the local post office or town hall, which may not 

correspond precisely to the locations of a place name 

on a site map provided in a given report. Therefore, 

locations derived using coordinates from GNIS will 

generally have more uncertainty than locations derived 

from exact LAT/LON coordinates on the base map of a 

report. The method described in this example can also 

be used for a site anywhere in the world, if the features 

can be located using the international NIMA data base 

(NIMA,1998), which is similar to the GNIS data base.

In this example, the latitude and longitude of the 

two hypothetical study sites along Interstate 93 in 

Boston, Massachusetts, were located using five map 

features on a site map that were identifiable in the 

GNIS data base (fig. 2). These five known featu

shown as filled triangles on figure 2, are listed a

place names on the I/O file shown in figure 4. T

coordinates for these features were recorded an

entered via manual input. For this example, the 

from the known LAT/LON coordinates was use

facilitate comparisons between the examples us

map coordinates and known locations (and for 

comparison to the calculations for the combined 

set illustrated in figure 1). If the LAT/LON coor

were not known, one feature, or the intersection 

LAT/LON axes of two features, could have bee

as an origin. For the features from GNIS, the a

number of seconds per UDCS measurement un

37.65 and -36.91 for latitude and longitude, 

respectively. These numbers were then used to 

calculate the LAT/LON coordinates of each site

standard deviation of the feature location averag

about 0.5 and 1 second per UDCS map unit for 

and longitude, respectively. Therefore, using tw

standard deviation, and the maximum distance 

the origin, the uncertainty in LAT/LON coordin

the site locations could be estimated to within p

minus 11 seconds. If this uncertainty is accepta

these results would be used. If not, the measure

of feature and site locations should be verified a

possibility of dropping and(or) adding features 

considered. For comparison, when the GNIS fe

and the map coordinate features were combined

average number of seconds per measurement un

37.61 and -37.11 for latitude and longitude, 

respectively, and the estimated uncertainty in th

LAT/LON coordinates of site locations was abo

or minus 9 seconds. 
12 Computer Program for Point Location And Calculation of ERror (PLACER)

 INPUT FILENAME: Sample2.txt

 MAP NAME: USGS QUAD Boston South, MA

 NUMBER OF MAP FEATURES: 5

 NUMBER OF STUDY SITES: 4

 OUTPUT FEATURE DDDMMSS SSSSSSSS X OR Y

 Lat & y: Map Origin at SW 0421500 152100 0.00

 Lon & x: Map Origin at SW 0710300 255780 0.00

 Lat & y: Thimble Island(GNIS) 0421827 152307 5.50

 Lon & x: Thimble Island(GNIS) 0710128 255688 2.45

 Lat & y: Savin Hill (GNIS) 0421838 152318 5.80

 Lon & x: Savin Hill (GNIS) 0710300 255780 0.00

 Lat & y: Forbes Hill (GNIS) 0421525 152125 0.65

 Lon & x: Forbes Hill (GNIS) 0710142 255702 2.10

 Lat & y: Halftide Rock (GNIS) 0421818 152298 5.30

 Lon & x: Halftide Rock (GNIS) 0710142 255702 2.20

 Lat & y: Norfolk Downs (GNIS) 0421620 152180 2.15

 Lon & x: Norfolk Downs (GNIS) 0710115 255675 2.80

 **********************************************************************

 OUTPUT SITE DDDMMSS SSSSSSSS X OR Y

 Lat & y: Tenean Beach Drain 0421736 152256 4.15

 Lon & x: Tenean Beach Drain 0710241 255761 0.52

 Lat & y: Interchange 20 Drain 0421709 152229 3.45

 Lon & x: Interchange 20 Drain 0710235 255755 0.70

 Lat & y: Known Coord3 0421800 152280 4.80

 Lon & x: Known Coord3 0710003 255603 4.80

 Lat & y: Norfolk Downs (GNIS) 0421620 152180 2.15

 Lon & x: Norfolk Downs (GNIS) 0710117 255677 2.80

 **********************************************************************

 FEATURE VALUES DLAT/DY DLAT DY

 Thimble Island (GNIS) 37.64 207 5.50

 Savin Hill (GNIS) 37.59 218 5.80

 Forbes Hill (GNIS) 38.46 25 0.65

 Halftide Rock (GNIS) 37.36 198 5.30

 Norfolk Downs (GNIS) 37.21 80 2.15

 **********************************************************************

 LAT AVG & STD DEV (SD): AVERAGE SD 2 X SD 3 X SD

 37.65 0.49 0.97 1.46

 **********************************************************************

 FEATURE VALUES DLON/DX DLON DX

 Thimble Island (GNIS) -37.55 -92 2.45

 Savin Hill (GNIS) 0.00 0 0.00

 Forbes Hill (GNIS) -37.14 -78 2.10

 Halftide Rock (GNIS) -35.45 -78 2.20

 Norfolk Downs (GNIS) -37.50 -105 2.80

 **********************************************************************

 LON AVG & STD DEV (SD): AVERAGE SD 2 X SD 3 X SD

 -36.91 0.99 1.98 2.97

 **********************************************************************

Figure 4. Calculation of site coordinates by the PLACER program using the latitude and longitude coordinates 

of map features located using the U.S. Geological Survey Geographic Names Information System (GNIS). 
Refere

SUMMARY

Well defined sampling-site locations are 

necessary to document data and to help establish that 

the data and the resultant interpretations are valid, 

current, and technically defensible. A program 

designed for point location and calculation of error 

(PLACER) was developed as part of the Quality 

Assurance Program of the Federal Highway 

Administration/U.S. Geological Survey National Data 

and Methodology Synthesis (NDAMS) review process, 

to provide a standard method to derive study-site 

locations from site maps in highway-runoff reports. 

Use of a base map from an environmental-monitoring 

report, the study-site locator form, and PLACER 

provides a documentable process that reduces or 

eliminates the potential for human error in 

interpolating site coordinates from published site maps. 

The purpose of this report is to (1) provide a guide for 

using PLACER, (2) to document the methods used to 

estimate study-site locations, (3) to document the 

NDAMS Study Site Locator Form (appendix 1), and 

(4) to document the FORTRAN code (appendix 2) 

used to implement the program method.

PLACER is a simple computer program that 

interpolates between known feature locations and 

unknown sites of interest on a published map using any 

consistent, linear, user-defined coordinate system 

(UDCS). PLACER is used to determine the LAT/LON 

of a point plotted on a map and to estimate the 

uncertainty of the LAT/LON coordinates calculated 

using input data. The program determines study-site 

locations in latitude and longitude using known map 

coordinates or features that are identifiable in available 

geographic information data bases. 

PLACER is configured to accept keyboard 

and(or) formatted data-file entry and to output results 

to the computer screen and to an ASCII text file. 

PLACER was developed using standard FORTRAN 

and, thus, the code should be readily transferable to 

different computers and operating systems, with few (if 

any) modifications. The FORTRAN code, and 

executable versions of PLACER for DOS/Windows, 

the Macintosh operating system, and Data General 

Unix, are available on disk.

REFERENCES

Granato, G.E., Bank, F.G., and Cazenas, P.A., 1998, 

quality objectives and criteria for basic informa

acceptable uncertainty, and quality assurance a

quality control documentation: U.S. Geologica

Open-File Report 98-394, 17 p.

Green Hills Software, Inc., 1990, Green Hills FORT

language reference manual, Santa Barbara, Cal

Green Hills Software, Inc., 285 p.

Hansen, W.R., 1991, Suggestions to authors of the re

the United States Geological Survey (7th ed.): 

Washington, D.C., U.S. Geological Survey, 289 

Intergovernmental Task Force on Monitoring Water 

1995a, The strategy for improving water-qualit

monitoring in the United States: U.S. Geologic

Survey Final Report, 25 p.

Intergovernmental Task Force on Monitoring Water 

1995b, The strategy for improving water-qualit

monitoring in the United States: U.S. Geologic

Survey Technical Appendixes, 117 p.

Jones, B.E., 1998, Principles and practices for qualit

assurance and quality control: U.S. Geological 

Open-File Report 98-636, 24 p.

Metrowerks Corporation, 1997, Metrowerks CodeW

User Guide MPW Version 3.4.2: Austin, Texas 

Metrowerks Corporation, 496 p.

Microsoft Corporation, 1989, Microsoft FORTRAN 

reference manual Version 5: Redmond, Washin

Microsoft Corporation, 523 p.

National Imagery and Mapping Agency (NIMA), 19

GEOnet Names Server, located on the World W

at http://164.214.2.59/gns/html/index.html, acc

December, 25, 1998.

Natural Resources Canada, 1998, Canadian Geograp

Names Server, located on the World Wide Web 

http://geonames.nrcan.gc.ca/english/Home.htm

accessed on December, 25, 1998.

U.S. Geological Survey (USGS), 1998a, Geographic 

Information System: U.S. Geological Survey Fa

127-95, 2 p.

U.S. Geological Survey (USGS), 1998b, Geographic 

Information System (GNIS) data base, located 

World Wide Web at http://mapping.usgs.gov/ww

accessed on December, 25, 1998.

APPENDIX 1: STUDY-SITE LOCATOR FORM

Appen

FHWA Project Study-Site Locator Form Version 2

Please attach: Copy of figure or table used to locate sites & program 

file printout

Person locating sites: __________________________________________

Report being reviewed: __________________________________________

Figure or table from which site locations were determined:

_____________________________________________________________

How determined: By text, by placer, by hand interpolation 

For Placer:

Final output file name: __________________________________

Origin:

Name of origin lat/y __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ 0. 00

 d d m m s s 

Name of origin lon/x __________________________________________

longitude: _ _ _ _ _ _ _ x location: _ _ _ 0. 00

 d d d m m s s 

Number of map features (up to 21): ____

1. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

2. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

3. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

1 of 6
18 Computer Program for Point Location And Calculation of ERror (PLACER)

4. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

5. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

6. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

7. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

8. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

9. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

2 of 6
Appen

10. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

11. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

12. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

13. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

14. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

15. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

3 of 6
20 Computer Program for Point Location And Calculation of ERror (PLACER)

16. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

17. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

18. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

19. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

20. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

21. Feature name __________________________________________

latitude: _ _ _ _ _ _ y location: _ _ _ . _ _

 d d m m s s 

longitude: _ _ _ _ _ _ _ x location: _ _ _ . _ _

 d d d m m s s 

4 of 6
Appen

Number of map sites (up to 21): ____

1. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

 

2. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

 

3. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

 

4. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

5. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

6. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

7. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

8. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

9. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

10. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

5 of 6
22 Computer Program for Point Location And Calculation of ERror (PLACER)

11. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

 

12. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

 

13. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

 

14. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

15. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

16. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

17. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

18. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

19. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

20. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

21. Site name __________________________________________

y location: _ _ _ . _ _ x location: _ _ _ . _ _

comments: ________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

6 of 6
APPENDIX 2: FORTRAN CODE FOR PLACER

Appen

C PLACER--Point Location And Calculation of ERror

C VERSION 2.0 UPDATED USER INTERFACE

C A program designed to assign a latitude and longitude (lat/lon) to

C points plotted on a map from “known” reference points, the program

C also estimates the uncertainty of the lat/lons generated by 

C calculating the standard deviation of the population of known 

C points.

C

C Programmed by Gregory E. Granato, ggranato@usgs.gov, October, 1997

C U.S. Geological Survey, Water Resources Division

C Massachusetts Rhode Island District, Northborough, MA 01532

C 

C Establish Variables

 IMPLICIT NONE

 CHARACTER*60 ifnm,ofnm,FNMOLD

 CHARACTER*20 feature(21),site(21),orgname

 CHARACTER*60 mapnm,JUNK*80

C

 INTEGER latfd(21),latfm(21),latfs(21)

 INTEGER latsd(21),latsm(21),latss(21)

 INTEGER lonfd(21),lonfm(21),lonfs(21) 

 INTEGER lonsd(21),lonsm(21),lonss(21)

 INTEGER LATF(21),LATS(21),LONF(21),LONS(21)

 INTEGER latdo(21),londo(21)

 INTEGER nf,ns,LONO,LATO,ok

 INTEGER lonod,lonom,lonos,latod,latom,latos,I

 INTEGER xnum,ynum,MANOR

C 

 REAL xs(21),ys(21),xf(21),yf(21),rx(21),ry(21),ydo(21),xdo(21)

 REAL XO,YO,xsum,ysum,xavg,yavg,sx,sy,sysum,sxsum,tmpx,tmpy

 REAL sxii,syii,sxiii,syiii

C

C SET ORIGINAL VALUES

C ON READ AND WRITE FUNCTIONS: * --keyboard and screen

C UNIT 10 -- INPUT FILE UNIT 11 --OUTPUT FILE

C

 orgname=’Map Origin at SW’

C WELCOME SCREEN

 10 WRITE (*,9000)

 WRITE (*,9010)

 WRITE (*,9020)

 WRITE (*,9000)

 WRITE (*,9030)

 WRITE (*,9040)

 WRITE (*,9050)

 WRITE (*,9060)

 WRITE (*,9070)

 WRITE (*,9080)

 WRITE (*,9090)

 WRITE (*,9100)
26 Computer Program for Point Location And Calculation of ERror (PLACER)

 WRITE (*,9110)

 WRITE (*,9000)

 WRITE (*,9000)

 WRITE (*,9200)

 WRITE (*,9210)

 READ (*,9211) MANOR

 WRITE (*,9000)

C RESPOND TO MODE CHOICE

C 0= BYE 1 = MANUAL 2=INPUT FILE ELSE=START AGAIN 

 IF (MANOR.EQ.0) THEN

 WRITE (*,9220)

 WRITE (*,9000)

 GOTO 900

 ELSEIF (MANOR.EQ.1) THEN

 WRITE (*,9230)

 WRITE (*,9000)

 GOTO 100

 ELSEIF (MANOR.EQ.2) THEN

 WRITE (*,9240)

 WRITE (*,9241)

 WRITE (*,9000)

 GOTO 200

 ELSE

 GOTO 10

 END IF

C ***************************************************

C MANUAL ENTRY

C ***************************************************

 100 WRITE (*,9302)

 READ (*,9312) OFNM

 WRITE (*,9310)

 READ (*,9312) MAPNM

 101 WRITE (*,9314) 

 READ (*,9318) NF

 IF ((NF.LT.1).OR.(NF.GT.21)) THEN

 WRITE (*,9315)

 GOTO 101

 END IF

 103 WRITE (*,9316) 

 READ (*,9318) NS

 IF ((NS.LT.1).OR.(NS.GT.21)) THEN

 WRITE (*,9315)

 GOTO 103

 END IF 

C CHECK MANUAL INPUT loop1 start

 WRITE (*,9000)

 WRITE (*,9900)

 WRITE (*,9340) OFNM

 WRITE (*,9342) MAPNM

 WRITE (*,9344) NF
Appen

 WRITE (*,9346) NS

 CALL getok(ok)

C WRITE (*,9951)

C READ (*,9952) OK

 if (ok.ne.0) goto 100

 WRITE (*,9000)

C CHECK MANUAL INPUT loop1 end

C INPUT ORIGIN IN IN LATLONG & MAP UNITS = 0,0

C 

 110 WRITE (*,9400)

 WRITE (*,9401)

 READ (*,9411) LATOD,LATOM,LATOS

 WRITE (*,9402)

 READ (*,9412) LONOD,LONOM,LONOS

C CONVERT DEGREES, MINUTES & SECONDS TO TOTAL SECONDS

 CALL DMS2S(LATOD,LATOM,LATOS,LATO)

 CALL DMS2S(LONOD,LONOM,LONOS,LONO)

 XO=0.00

 YO=0.00

 WRITE (*,9722)

 write (*,9725) orgname,LATOD,LATOM,LATOS,lato,YO

 write (*,9726) orgname,LONOD,LONOM,LONOS,lono,XO

c check loop 2. start

 CALL getok(ok)

c write (*,9951)

c read (*,9952) ok

 if (ok.ne.0) goto 110

 WRITE (*,9000)

c check loop 2. end

C

C INPUT FEATURE LOCATIONS IN LATLONG & MAP UNITS

C

 DO 130, I=1,NF

 120 WRITE (*,9410) I

 WRITE (*,9405) 

 READ (*,9415) FEATURE(I)

 WRITE (*,9401)

 READ (*,9411) LATFD(I),LATFM(I),LATFS(I)

 WRITE (*,9404)

 READ (*,9414) YF(I)

 WRITE (*,9402)

 READ (*,9412) LONFD(I),LONFM(I),LONFS(I)

 WRITE (*,9403)

 READ (*,9413) XF(I)

C CONVERT DEGREES, MINUTES & SECONDS TO TOTAL SECONDS

 CALL DMS2S(LATFD(I),LATFM(I),LATFS(I),LATF(I))

 CALL DMS2S(LONFD(I),LONFM(I),LONFS(I),LONF(I))

 WRITE (*,9722)

 write (*,9725) feature(I),LATFD(I),LATFM(I),LATFS(I),LATF(I),yf(I)

 write (*,9726) feature(I),LonFD(I),LonFM(I),LonFS(I),LonF(I),xf(I)
28 Computer Program for Point Location And Calculation of ERror (PLACER)

c check loop 3. start

 CALL getok(ok)

c write (*,9951)

c read (*,9952) ok

 if (ok.ne.0) goto 120

 WRITE (*,9000)

c check loop 3. end

 130 CONTINUE

C END FEATURE LOOP

C

C INPUT SITE LOCATIONS IN LATLONG & MAP UNITS

C

 DO 150, I=1,NS

 140 WRITE (*,9409) I

 WRITE (*,9406) 

 READ (*,9416) SITE(I)

 WRITE (*,9404)

 READ (*,9414) YS(I)

 WRITE (*,9403)

 READ (*,9413) XS(I)

 WRITE (*,9500) 

 WRITE (*,9510) SITE(I), YS(I)

 WRITE (*,9520) SITE(I), XS(I)

c check loop 4. start

 CALL getok(ok)

c write (*,9951)

c read (*,9952) ok

 if (ok.ne.0) goto 140

 WRITE (*,9000)

c check loop 4. end

 150 CONTINUE

C ***************************************************

C GOTO CALCULATION AND DATA RECORDING

 GOTO 300

C

C ***************************************************

C INPUT FILE ENTRY

C ***************************************************

 200 WRITE (*,9300)

 READ (*,9304) IFNM

 WRITE (*,9302)

 READ (*,9304) OFNM

C CHECK FILE ENTRY/KEYBOARD INPUT loop1 start

 IF (IFNM.EQ.OFNM) THEN

 WRITE (*,9301)

 GOTO 200

 ENDIF

 WRITE (*,9900)

 WRITE (*,9340) IFNM

 WRITE (*,9341) OFNM
Appen

 CALL getok(ok)

c WRITE (*,9951)

c READ (*,9952) OK

 WRITE (*,9000)

 if (ok.ne.0) goto 200

C CHECK FILE ENTRY/KEYBOARD INPUT loop1 end

 OPEN (UNIT=10,FILE=Ifnm)

 READ (10,8342) FNMOLD

 READ (10,8342) MAPNM

 READ (10,8344) NF

 READ (10,8346) NS

 WRITE (*,9000)

 WRITE (*,9700)

 WRITE (*,9900)

 WRITE (*,9340) OFNM

 WRITE (*,9342) MAPNM

 WRITE (*,9344) NF

 WRITE (*,9346) NS

 WRITE (*,9700)

C READ FINAL FEATURE NAME, LAT/LON, & XY COORDINATES FROM FILE

 READ (10,8700) JUNK

 WRITE (*,8700) JUNK

 READ (10,8725) orgname,LATOD,LATOM,LATOS,YO

 READ (10,8725) orgname,LONOD,LONOM,LONOS,XO

 CALL DMS2S(LATOD,LATOM,LATOS,LATO)

 CALL DMS2S(LONOD,LONOM,LONOS,LONO)

 write (*,9725) orgname,LATOD,LATOM,LATOS,lato,YO

 write (*,9726) orgname,LONOD,LONOM,LONOS,lono,XO

 do 220, i=1,nF 

 READ (10,8725) feature(I),LATFD(I),LATFM(I),LATFS(I),yf(I)

 READ (10,8725) feature(I),LonFD(I),LonFM(I),LonFS(I),xf(I)

 CALL DMS2S(LATFD(I),LATFM(I),LATFS(I),LATF(I))

 CALL DMS2S(LONFD(I),LONFM(I),LONFS(I),LONF(I))

 write (*,9725) feature(I),LATFD(I),LATFM(I),LATFS(I),LATF(I),yf(I)

 write (*,9726) feature(I),LonFD(I),LonFM(I),LonFS(I),LonF(I),xf(I)

 220 CONTINUE

C Dont READ line of asterix

 READ (10,8700) JUNK

 WRITE (*,8700) JUNK

C Dont READ header

 READ (10,8700) JUNK

 WRITE (*,8700) JUNK

c read site info

 do 240, i=1,ns

 READ (10,8726) site(i),yS(I)

 READ (10,8726) site(i),xS(I)

 write (*,7725) site(i),yS(I)

 write (*,7726) site(i),xS(I)

 240 CONTINUE

C Dont READ OLD CALCULATION RESULTS
30 Computer Program for Point Location And Calculation of ERror (PLACER)

C ***************************************************

C GOTO CALCULATION AND DATA RECORDING

 GOTO 300 

C

C ***************************************************

C CALCULATION AND DATA RECORDING

C ***************************************************

C INITIALIZE POPULATION/SUMMATION VARIABLES

 300 WRITE (*,9700)

 WRITE (*,9990)

 WRITE (*,9700)

 xsum=0.00

 ysum=0.00

 sxsum=0.00

 sysum=0.00

 xnum=0.00

 ynum=0.00

 tmpx=0.0

 tmpy=0.0

 sx=0.0

 sy=0.0

C ***************************************************

C CALCULATE THE NUMBER OF LAT/LON SECONDS PER MAP UNIT DSEC/DMAP

C FOR EACH OF THE FEATURES

 DO 320, I=1,NF

C COMPUTE DISTANCE TO ORIGIN

 latdo(i)=latf(i)-lato

 londo(i)=lonf(i)-lono

 xdo(i)=xf(i)-xo

 ydo(i)=yf(i)-yo

C USE NON-ORIGIN FEATURES TO CALCULATE STATISTICS

C X & LON

 if (xdo(i).ne.0.00) then

 rx(i)=(real(londo(i)))/xdo(i)

 xsum=rx(i)+xsum

 sxsum=(rx(i)*rx(i))+sxsum 

 xnum=xnum+1

 else

 xsum=xsum

 sxsum=sxsum

 xnum=xnum

 endif

C Y & LAT

 if (ydo(i).ne.0.00) then

 ry(i)=(real(latdo(i)))/ydo(i)

 ysum=ry(i)+ysum

 sysum=(ry(i)*ry(i))+sysum

 ynum=ynum+1

 else
Appen

 ysum=ysum

 sysum=sysum

 ynum=ynum

 endif 

 320 continue

C CALCULATE MEAN DSEC/DMAP 

 xavg=xsum/(real(xnum))

 yavg=ysum/(real(ynum))

C CALCULATE STANDARD DEVIATION DSEC/DMAP

 tmpx=(sxsum-((xsum*xsum)/xnum))

 tmpy=(sysum-((ysum*ysum)/ynum))

 if ((xnum-1).ne.0.00) sx=(sqrt(tmpx/(real(xnum-1))))

 if ((ynum-1).ne.0.00) sy=(sqrt(tmpy/(real(ynum-1))))

 sxii=2.0*sx

 sxiii=3.0*sx

 syii=2.0*sy

 syiii=3.0*sy

C ***************************************************

C CALCULATE THE LAT/LONS FROM MEAN DSEC/DMAP AND SITE X & Y INFO

 do 340, i=1,ns

 lons(i)=lono+(int(xs(i)*xavg))

 lats(i)=lato+(int(ys(i)*yavg))

 call s2dms(lons(i),lonsd(i),lonsm(i),lonss(i))

 call s2dms(lats(i),latsd(i),latsm(i),latss(i))

 340 CONTINUE

C ***************************************************

C PRINT ALL TO SCREEN

C ***************************************************

 600 CONTINUE

C

C PRINT FINAL FEATURE INFORMATION TO THE SCREEN

 WRITE (*,9722)

 write (*,9725) orgname,LATOD,LATOM,LATOS,lato,YO

 write (*,9726) orgname,LONOD,LONOM,LONOS,lono,XO

 do 620, i=1,nF 

 write (*,9725) feature(I),LATFD(I),LATFM(I),LATFS(I),LATF(I),yf(I)

 write (*,9726) feature(I),LonFD(I),LonFM(I),LonFS(I),LonF(I),xf(I)

 620 CONTINUE

C PRINT FINAL CALCULATION INFORMATION TO THE SCREEN

 WRITE (*,9700)

 WRITE (*,9820) 

 do 624, i=1,nF

 write(*,9860) feature(I),ry(i),latdo(i),ydo(i)

 624 CONTINUE

 WRITE (*,9700)

 WRITE (*,9822) 

 WRITE (*,9862) YAVG,SY,SYII,SYIII

 WRITE (*,9700)

 WRITE (*,9840) 
32 Computer Program for Point Location And Calculation of ERror (PLACER)

 do 626, i=1,nF

 write(*,9860) feature(I),rx(i),londo(i),xdo(i)

 626 CONTINUE

 WRITE (*,9700)

 WRITE (*,9842) 

 WRITE (*,9862) XAVG,SX,SXII,SXIII

 WRITE (*,9700)

C 

C PRINT FINAL SITE INFORMATION TO THE SCREEN

 WRITE (*,9723)

 do 640, i=1,ns

 write (*,9725) site(i),LATSD(I),LATSM(I),LATSS(I),LATS(I),yS(I)

 write (*,9726) site(i),LonSD(I),LonSM(I),LonSS(I),LonS(I),xS(I)

 640 CONTINUE

C

C ***************************************************

C OPEN THE OUTPUT FILE AND BEGIN DATA RECORDING

C ***************************************************

 700 OPEN (UNIT=11,FILE=ofnm)

 WRITE (11,9340) OFNM

 WRITE (11,9342) MAPNM

 WRITE (11,9344) NF

 WRITE (11,9346) NS

C

C PRINT FINAL FEATURE INFORMATION TO THE FILE

 WRITE (11,9722)

 write (11,9725) orgname,LATOD,LATOM,LATOS,lato,YO

 write (11,9726) orgname,LONOD,LONOM,LONOS,lono,XO

 do 720, i=1,nF 

 write(11,9725) feature(I),LATFD(I),LATFM(I),LATFS(I),LATF(I),yf(I)

 write(11,9726) feature(I),LonFD(I),LonFM(I),LonFS(I),LonF(I),xf(I)

 720 CONTINUE

 WRITE (11,9700)

C PRINT FINAL SITE INFORMATION TO THE FILE

 WRITE (11,9723)

 do 740, i=1,ns

 write (11,9725) site(i),LATSD(I),LATSM(I),LATSS(I),LATS(I),yS(I)

 write (11,9726) site(i),LonSD(I),LonSM(I),LonSS(I),LonS(I),xS(I)

 740 CONTINUE

C PRINT FINAL CALCULATION INFORMATION TO THE FILE

 WRITE (11,9700)

 WRITE (11,9820) 

 do 744, i=1,nF

 write(11,9860) feature(I),ry(i),latdo(i),ydo(i)

 744 CONTINUE

 WRITE (11,9700)

 WRITE (11,9822) 

 WRITE (11,9862) YAVG,SY,SYII,SYIII

 WRITE (11,9700)

 WRITE (11,9840) 
Appen

 do 746, i=1,nF

 write(11,9860) feature(I),rx(i),londo(i),xdo(i)

 746 CONTINUE

 WRITE (11,9700)

 WRITE (11,9842) 

 WRITE (11,9862) XAVG,SX,SXII,SXIII

 WRITE (11,9700)

C

C ***************************************************

C END DATA RECORDING

C ***************************************************

C FORMAT STATEMENTS 7000’S FOR INPUT FILE screen write

 7725 FORMAT (1X,’ Site y: ‘,1a20,19x,1f10.2) 

 7726 FORMAT (1X,’ Site x: ‘,1a20,19x,1f10.2)

C FORMAT STATEMENTS 8000’S FOR INPUT FILE

 8341 FORMAT (18X,1A20)

 8342 FORMAT (11X,1A60)

 8344 FORMAT (25X,1i2)

 8346 FORMAT (24X,1i2)

 8700 FORMAT (1A80)

 8725 FORMAT (11X,1a20,2x,1i3.3,2i2.2,10X,1f10.2)

 8726 FORMAT (11X,1a20,19x,1f10.2)

C FORMAT STATEMENTS 9000’S FOR SCREEN ENTRY

 9000 FORMAT (1X,’****************************************************’)

 9010 FORMAT (1X,’********************** PLACER **********************’)

 9020 FORMAT (1X,’***** Point Location And Calculation of ERror *****’)

 9030 FORMAT (1X,’* ENTER FILE NAME, MAP NAME, THE NUMBER OF SITES, *’)

 9040 FORMAT (1X,’* AND THE NUMBER OF MAP FEATURES FROM GLIS OR A *’)

 9050 FORMAT (1X,’* MAP AS WELL AS LAT, LONG & LOCATION OF SITES *’)

 9060 FORMAT (1X,’* AND FEATURES THIS PROGRAM WILL PRODUCE LAT AND *’)

 9070 FORMAT (1X,’* LONG FOR SITES OF INTEREST. IT IS ADVISABLE TO *’)

 9080 FORMAT (1X,’* ENTER AT LEAST ONE FEATURE AS A SITE AS WELL AS *’)

 9090 FORMAT (1X,’* AN INPUT FEATURE TO CHECK YOUR IMPLEMENTATION. *’)

 9100 FORMAT (1X,’* PROGRAM ASSUMES +X IS -LONG AND +Y IS +LAT BUT *’)

 9110 FORMAT (1X,’* OTHER INTERNALLY CONSISTENT AXES SHOULD WORK. *’) 

 9200 FORMAT (1X,’* CHOOSE DATA ENTRY MODE *’)

 9210 FORMAT (1X,’ENTER: MANUAL(1ST TIME)=1 INPUT FILE=2 EXIT=0 :’,$)

 9211 FORMAT (1i1)

 9220 FORMAT (1X,’ GOOD BYE!’)

 9230 FORMAT (1X,’ KEYBOARD INPUT’)

 9240 FORMAT (1X,’ INPUT FILE: READS ONLY THE DATA FROM A PLACER’) 

 9241 FORMAT (1X,’ OUTPUT FILE FORMAT (ORIGINAL OR EDITED)’)

 9300 FORMAT (1X,’ENTER THE INPUT FILENAME (UP TO 60 CHARACTERS): ‘,$)

 9301 FORMAT (1X,’INPUT AND OUTPUT FILENAMES CANNOT MATCH’)

 9302 FORMAT (1X,’ENTER THE OUTPUT FILENAME (UP TO 60 CHARACTERS): ‘,$)

 9304 FORMAT (1A20)

 9310 FORMAT (1X,’ENTER THE MAP NAME (UP TO 60 CHARACTERS): ‘,$)

 9312 FORMAT (1A60)

 9314 FORMAT (1X,’ENTER THE NUMBER OF MAP FEATURES (21 POSSIBLE): ‘,$)

 9315 FORMAT (1X,’**** ERROR DETECTED, PLEASE TRY AGAIN  ’,)
34 Computer Program for Point Location And Calculation of ERror (PLACER)

 9316 FORMAT (1X,’ENTER THE NUMBER OF STUDY SITES (21 POSSIBLE): ‘,$)

 9318 FORMAT (1i2)

 9340 FORMAT (1X,’INPUT FILENAME: ‘,1A60)

 9341 FORMAT (1X,’OUTPUT FILENAME: ‘,1A60)

 9342 FORMAT (1X,’MAP NAME: ‘,1A60)

 9344 FORMAT (1X,’NUMBER OF MAP FEATURES: ‘,1i2)

 9346 FORMAT (1X,’NUMBER OF STUDY SITES: ‘,1i2)

 9400 FORMAT (1X,’ENTER LAT/LON FOR THE ORIGIN (X&Y DEFAULT = 0.00): ‘)

 9410 FORMAT (1X,’ENTER LAT/LON AND LOCATION FOR FEATURE #’,1I2)

 9409 FORMAT (1X,’ENTER LOCATION FOR SITE #’,1I2)

 9401 FORMAT (1X,’INPUT LAT DDMMSS : ‘,$)

 9411 FORMAT (3I2)

 9402 FORMAT (1X,’INPUT LON DDDMMSS : ‘,$)

 9412 FORMAT (1I3,2I2) 

 9403 FORMAT (1X,’INPUT X IN UNITS FROM ORIGIN (Use decmal: 1=0.01): ‘,$

 +)

 9413 FORMAT (1g10.2) 

 9404 FORMAT (1X,’INPUT Y IN UNITS FROM ORIGIN (Use decmal: 1=0.01): ‘,$

 +)

 9414 FORMAT (1g10.2) 

 9405 FORMAT (1X,’INPUT FEATURE NAME (UP TO 20 CHARACTERS): ‘,$)

 9415 FORMAT (1A20)

 9406 FORMAT (1X,’INPUT SITE NAME (UP TO 20 CHARACTERS): ‘,$)

 9416 FORMAT (1A20)

C SCREEN/FILE OUTPUT

 9500 FORMAT (1X,’ OUTPUT ‘,1x,’SITE ‘,15X,’ X OR Y’)

 9510 FORMAT (1X,’ SITE Y ‘,1x,1A20,2X,1F10.2)

 9520 FORMAT (1X,’ SITE X ‘,1x,1A20,2X,1F10.2)

C 

 9700 FORMAT (1X,’** ****************************************************

 +****************’)

 9705 FORMAT (‘ dlon/dx ‘,1a20,2x,1i8,3f10.3)

 9706 FORMAT (‘ dlat/dy ‘,1a20,2x,1i8,3f10.3)

 9720 FORMAT (‘ site lat: ‘,1a20,1f10.2,2x,1i8,2x,1i3.3,2i2.2)

 9721 FORMAT (‘ site lon: ‘,1a20,1f10.2,2x,1i8,2x,1i3.3,2i2.2)

C

C SCREEN & FILE OUTPUT

C

 9722 FORMAT (1X,’ OUTPUT ‘,1x,’FEATURE’,15X,’DDDMMSS’,2X,’SSSSSSSS’,’

 + X OR Y’)

 9723 FORMAT (1X,’ OUTPUT ‘,1x,’SITE ‘,15X,’DDDMMSS’,2X,’SSSSSSSS’,’

 + X OR Y’)

 9725 FORMAT (1X,’ Lat & y: ‘,1a20,2x,1i3.3,2i2.2,2X,1i8,1f10.2)

 9726 FORMAT (1X,’ Lon & x: ‘,1a20,2x,1i3.3,2i2.2,2X,1i8,1f10.2)

 9820 FORMAT (2X,’FEATURE VALUES’,8X,’ DLAT/DY’,5X,’DLAT’,9X,’DY’)

 9822 FORMAT (2X,’LAT AVG & STD DEV (SD):’,2x,’AVERAGE’,8X,’SD’,4X,’2 X 

 +SD’,4X,’3 X SD’)

 9840 FORMAT (2X,’FEATURE VALUES’,8X,’ DLON/DX’,5X,’DLON’,9X,’DX’)

 9842 FORMAT (2X,’LON AVG & STD DEV (SD):’,2x,’AVERAGE’,8X,’SD’,4X,’2 X 

 +SD’,4X,’3 X SD’)
Appen

 9860 FORMAT (2X,1A20,2X,1F10.2,1X,1I8,1X,1F10.2)

 9862 FORMAT (2X,22X,4F10.2)

C

C FEEDBACK LOOP

 9900 FORMAT (1X,’CHECK INPUT DATA’)

 9951 FORMAT (1X,’* If values are ok hit 0 or enter, if not hit 1:’,$)

 9952 FORMAT (1i1)

 9990 format (1x,’BEGIN CALCULATIONS’)

C 

C

C

C CLOSE THE OPEN UNITS (FILES)

 898 CLOSE (10) 

 899 CLOSE (11) 

C END PROGRAM

 900 STOP

 END

C

C

C ***********************************************

C

C SUBROUTINES

C

C ***********************************************

C

 subroutine dms2s(ddd,mm,ss,sssss)

c converts degrees min and sec to total sec

 integer ddd,mm,ss,sssss

 sssss=(ddd*60*60)+(mm*60)+ss

 return

 end

c

 subroutine s2dms(sssss,ddd,mm,ss)

c converts total sec to degrees min and sec

 integer ddd,mm,ss,sssss

 ddd=int(sssss/(60*60))

 mm=int((sssss-(ddd*60*60))/60)

 ss=int((sssss-(ddd*60*60)-(mm*60)))

 return

 end

c

 subroutine getok(ok)

C reads input & corrects to number value

 integer ok

 character*60 oktext

 10 WRITE (*,9951)

 read (*,9000) oktext

 if (oktext.eq.’0’) then

 ok=0

 elseif (oktext.eq.’ ‘) then
36 Computer Program for Point Location And Calculation of ERror (PLACER)

 ok=0

 elseif (oktext.eq.’1’) then

 ok=1

 else

 goto 10

 endif

 9000 format (1A1)

 9951 FORMAT (1X,’* If values are ok hit 0 or enter, if not hit 1:’,$) 

 return

 end 
District Chief,Massachusetts—Rhode Island DistrictU.S. Geological SurveyWater Resources Division10 Bearfoot Rd.Northborough, MA 01532