# Presentation: 552163

**DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM**
**HOUSTON**
**DECEMBER 13, 2003**
**David Doyle**
**Chief Geodetic Surveyor**
**National Geodetic Survey**
**Dave.Doyle@noaa.gov, (301) 713-3178**
**                               **

## ACRONYMS         US

- NAD 83

- WGS 84

- ITRF 00

- GRS 80

- EGM 96

- HARN

*HPGN*

- NAVD 88

- NGVD 29

- NAD 27

- ACRONYMS         US

- NSRS

- CORS

## NATIONAL GEODETIC SURVEY 

**INFORMATION CENTER**
**(301) 713-3242**
**info_center@ngs.noaa.gov**

**WEB SITE**
**http://www.ngs.noaa.gov**

## Slide 4

## GEODETIC CONTROL

- NETWORK OF MONUMENTED POINTS
- PRECISELY MEASURED IN ACCORDANCE
- WITH STANDARD PROCEDURES
- MEET ACCURACY SPECIFICATIONS
- ADJUSTED TO TIE TOGETHER
- DOCUMENTED FOR MULTIPLE USE

## Poured in place 

**Poured in place **
**concrete post**

**Stainless steel rod **
**driven to refusal**

## CORS SITES

**CORS SITES**

## NATIONAL SPATIAL REFERENCE SYSTEM(http://www.ngs.noaa.gov)

- The National Spatial Reference System (NSRS) is that component of the National Spatial Data Infrastructure (NSDI) - [http://www.fgdc.gov/nsdi/nsdi.html] which contains all geodetic control contained in the National Geodetic Survey (NGS) Data Base.  This includes:  A, B, First, Second and Third-Order horizontal and vertical control, Geoid models such as GEOID 99, precise GPS orbits and Continuously Operating Reference Stations (CORS),  and the National Shoreline as observed by NGS as well as data submitted by other Federal, State, and local agencies, Academic Institutions and the private sector

## NATIONAL SPATIAL REFERENCE SYSTEM

**ACCURATE**** ****-- ****cm accuracy on a global scale**
**MULTIPURPOSE**** ****--  ****Supports Geodesy, Geophysics, Land Surveying, Navigation, Mapping, Charting and GIS activities**
**ACTIVE**** ****--  ****Accessible through Continuously Operating Reference Stations (CORS) and derived products**
**INTEGRATED**** ****-- ****Related to International services and standards (e.g. International Earth Rotation and Reference Systems Service, International ****GPS Service etc.)**

## METADATA

-      METADATA IS DATA ABOUT DATA
_**DATUMS**_** ****	**
- NAD 27, NAD 83(1986), NAD83 (199X),
- NGVD29, NAVD88
_**UNITS**_
- Meters, U.S. Survey Feet, International Feet, Vara, Toise, Chains, Rods, Poles, Links, Perchs, Smoots
_**ACCURACY**_
- 	A, B, 1st, 2nd, 3rd, 3cm, Scaled

## METADATA??

**METADATA??**

**Horizontal Datum??**

**Plane Coordinate Zone ??**

**Units of Measure ??**

**How Accurate ??**

## METADATA??

**METADATA??**

## THE ELLIPSOIDMATHEMATICAL MODEL OF THE EARTH

- b

- a

-  a = Semi major axis
-  b = Semi minor axis
-  f =  _a-b_ = Flattening
-          a

- N

- S

## ELLIPSOID - GEOID RELATIONSHIP

**H**

**h**

- Ellipsoid
- GRS80

**H = Orthometric Height**  **(NAVD 88)**

**N**

- Geoid

**H**** ****=**** ****h**** ****-**** ****N**

- TOPOGRAPHIC SURFACE

**h = Ellipsoidal Height (NAD 83)**

**N = Geoid Height (GEOID 99)**

- GEOID99

## UNITED STATESELLIPSOID DEFINITIONS

**CLARKE 1866**
**      ****a = 6,378,206.4 m     1/f = 294.97869821**

**GEODETIC REFERENCE SYSTEM 1980 - (GRS 80)**
**a = 6,378,137 m        1/f =**** ****298.257222101**

**WORLD GEODETIC SYSTEM 1984 - (WGS 84)**
**        ****a = 6,378,137 m       1/f =**** ****298.257223563**

**BESSEL 1841**
**      ****a = 6,377,397.155 m  1/f = 299.1528128**

**Notes:**
There have been several different ellipsoids used for the horizontal datums of the United States.  The Bessell 1841 ellipse was used from approximately 1845 until 1879.  Clarke 1866, developed by the English Geodesist A. R. Clarke was adopted in 1879 following the completion of the great Transcontinential Arc of Triangulation as it most closely approximates the size and shape of North America.  As part of the activity to complete the North American Datum of 1983 (NAD 83), In 1979, the National Geodetic Survey decieded to adopt the Geodetic Reference System 1980 (GRS 80) as recommended by the International Association of Geodesy, as it most closely reflects the size and shape of the entire globe.  It should be noted that GRS80 is for all practical purposes, the same size and shape as the World Geodetic System of 1984 (WGS 84) ellipsoid used with the Global Positioning System (GPS).  The small numerical differences in the flattening (1/f) amount to less than 0.1 millimeter from the most northern part of Alaska to the southern tip of Florida!!

## HORIZONTAL DATUMS

**BESSEL**** ****1841** --------------   	LOCAL ASTRO DATUMS (1816-1879)
-                                               	NEW ENGLAND DATUM (1879-1901)
-                                              	U.S. STANDARD DATUM (1901-1913)
-                                               	NORTH AMERICAN DATUM (1913-1927)
-                                              	NORTH AMERICAN DATUM OF 1927
- 	                                   	OLD  HAWAIIAN DATUM
-  **CLARKE 1866**     		PUERTO RICO DATUM
-                                               	ST. GEORGE ISLAND - ALASKA
-                                               	ST. LAWRENCE ISLAND - ALASKA
-                                               	ST. PAUL ISLAND - ALASKA
-                                               	AMERICAN SAMOA 1962
-                                               	GUAM 1963
-  **GRS80 ----------- ** 	NORTH AMERICAN DATUM OF 1983
-                                                    (As of June 14, 1989)

## COMPARISON OF DATUM ELEMENTS

-                                                        _NAD 27_                    _NAD 83_
- ELLIPSOID        		CLARKE 1866		   GRS80
-               a = 6,378,206.4 m                               a = 6,378,137. M
-            1/f = 294.9786982                               1/f = 298.257222101
- DATUM POINT                    Triangulation Station                                       NONE
-     MEADES RANCH, KANSAS               EARTH MASS CENTER
- ADJUSTMENT       	  25k STATIONS	                 250k STATIONS
-      Several Hundred Base Lines             Appox. 30k EDMI Base Lines
-      Several Hundred Astro Azimuths               5k Astro Azimuths
-                                                                      Doppler Point Positions
-                                                                             VLBI Vectors
- BEST FITTING                             North America                                      World-Wide

## NAD 27 and NAD 83

**NAD 27 and NAD 83**

## NAD 83 NETWORK PROBLEMS

- NOT “GPSABLE”

- POOR STATION ACCESSIBILITY

- IRREGULARLY SPACED

- POSITIONAL ACCURACY

## HIGH ACCURACY REFERENCE NETWORKS

- “GPSABLE”
- Clear Horizons for Satellite Signal Acquisition
- EASY ACCESSIBILITY
- Few Special Vehicle or Property Entrance Requirements
- REGULARLY SPACED
- Always within 20-100 Km
- HIGH HORIZONTAL ACCURACY
- A-Order (5 mm + 1:10,000,000)
- B-Order (8mm + 1:1,000,000)

## IMPROVING POSITIONAL ACCURACY

-                       TIME         NETWORK          LOCAL
- _NETWORK  SPAN        ACCURACY       ACCURACY_
- NAD 27                        1927-1986              10 Meters 	            First-Order (1 part in 0.1 million)
- NAD 83                        1986-1990                1 Meter                  First-Order(1 part in 0.1 million)
- HPGN/HARN                1987-1997            0.1 Meter                   B-Order(1 part in 1 million)
-                                                                                                      A-Order (1 part in 10 million)
- CORS                            1994 -                        	     0.02 Meter - Horizontal
-                                                                                         0.04 Meter - Ellipsoid Height

## HIGH ACCURACY REFERENCE  NETWORK

## HIGH ACCURACY REFERENCE NETWORKS

**TEXAS HARN**

## INTERNATIONAL TERRESTRIALREFERENCE SYSTEM

- DEVELOPED AND MAINTAINED BY THE
-  INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEM SERVICE
- PARIS, FRANCE
- (http://http://www.iers.org/)
- VERY LONG BASELINE INTERFEROMETRY - (VLBI)
- SATELLITE LASER RANGING - (SLR)
- GLOBAL POSITIONING SYSTEM - (GPS)
- DOPPLER ORBITOGRAPHY AND RADIO POSITIONING
- INTEGRATED BY SATELLITE - (DORIS)

## INTERNATIONAL TERRESTRIALREFERENCE SYSTEM

- GEOCENTRIC +/- 3 to 4 CM
- MODELS FOR PLATE TECTONICS
- STATION VELOCITIES
- POSITIONAL STANDARD ERRORS
- REALIZED AS THE INTERNATIONAL TERRESTERIAL REFERENCE FRAME (ITRF)

## WORLD GEODETIC SYSTEM 1984TR8350.2 World Geodetic System 1984 - It’s Definition andRelationships with Local Geodetic Systems(http://www.nima.mil/GandG/pubs.html)

**WORLD GEODETIC SYSTEM 1984*****TR8350.2 World Geodetic System 1984 - It’s Definition and******Relationships with Local Geodetic Systems*****(http://www.nima.mil/GandG/pubs.html)**

**DATUM = WGS 84(G730)**
**5 USAF GPS Tracking Stations**
**5 DMA Evaluation Stations **
**Datum redefined with respect to the International Terrestrial Reference Frame of 1992 (ITRF92) +/- 20 cm in each component **
**(Proceedings of the ION GPS-94 pgs 285-292)**

**DATUM = WGS 84(G873)**
**5 USAF GPS Tracking Stations**
**7 NIMA Evaluation Stations **
**Datum redefined with respect to the International Terrestrial Reference Frame of 1994 (ITRF94) +/- 10 cm in each component **
**(Proceedings of the ION GPS-97 pgs 841-850)**

**DATUM = WGS 84**
**RELEASED - SEPTEMBER 1987**
**BASED ON OBSERVATIONS AT MORE THAN 1900 DOPPLER STATIONS**

**DATUM = WGS 84(G1150)**
**Datum redefined with respect to the International **
**Terrestrial Reference Frame of 2000 (ITRF00) **
**+/- 2 cm in each component **
**(Proceedings of the ION GPS-02) **
**http://164.214.2.59/GandG/sathtml/IONReport8-20-02.pdf**

**HOW MANY WGS 84s **
**HAVE THERE BEEN????**

## MY SOFTWARE SAYS I’M WORKING IN WGS-84

**Project tied to WGS-84 control point obtained from the Defense Department **
**-- Good Luck! --**

**You’re really working in the same reference frame **
**as your control points -- NAD 83?**

**Unless you doing autonomous positioning **
**(point positioning +/- 6-10 meters) **
**you’re probably NOT in WGS-84**

## TRANSFORM BETWEEN WGS 84 & NAD 83

**TRANSFORM BETWEEN WGS 84 & NAD 83**

**dX =  0.9956 m**
**dY = -1.9013 m**
**dZ = -0.5215 m**

## THE GEOID AND TWO ELLIPSOIDS

**GRS80-WGS84**

**CLARKE 1866**

**GEOID**

- Earth Mass
-   Center

- Approximately
-    236 meters

## TECTONIC MOTIONS

## HORIZONTAL TECTONIC MOTIONS

**HORIZONTAL TECTONIC MOTIONS**

## VERTICAL TECTONIC MOTIONS

##   NAD 83 and ITRF / WGS 84

**ITRF / WGS 84**

**NAD**** ****83**

- Earth Mass
-   Center

-  2.2  m (3-D)
-   dX,dY,dZ

**GEOID**

## VERTICAL DATUMS

- MEAN SEA LEVEL DATUM OF 1929
- NATIONAL GEODETIC VERTICAL DATUM OF  1929
- (As of July 2, 1973)
- NORTH AMERICAN VERTICAL DATUM OF 1988
- (As of  June 24, 1993)

## COMPARISON OF VERTICAL DATUM ELEMENTS

- 				     _NGVD 29_                          _NAVD 88_
- DATUM DEFINITION                26  TIDE GAUGES                    FATHER’S POINT/RIMOUSKI
-                                                 IN THE U.S. & CANADA                       QUEBEC,  CANADA
- BENCH MARKS       	              100,000                                                450,000
- LEVELING (Km)                                102,724                                              1,001,500
- GEOID FITTING                   Distorted  to Fit MSL Gauges                  Best Continental Model

## NGVD 29  and NAVD 88

**NGVD 29  and NAVD 88**

## MHHW

**MHHW**

**Notes:**
Highest and Lowest Observed are not a tidal datum or a computation.
The acronyms can be found in our reference Glossary

Standard Method (MTL, MSL, Mn, DHQ & DLG are known):
MLW= MTL-(0.5*Mn)
MHW= MLW+Mn
MLLW= MLW-DLQ
MHHW= MHW-DHQ
DTL= 0.5*(MHHW+MLLW)
GT= MHHW-MLLW

MRR Method (MTL, DTL, MSL, Mn & GT are known):
MLW= MTL-(0.5*Mn)
MHW= MLW+Mn
MLLW= MLW-0.5*GT
MHHW= MHW+GT
DHQ= MHHW-MHW
DLQ= MLW-MLLW

GT is known as the spring or diurnal range depending on what coast it is on.

## Datum’s Boundary Applications

**Datum’s Boundary Applications**

**Notes:**
Boundaries to talk about in order of graphic enhancements: 
#MLW 
#MHW
A coastal home owner would have more land if living in CT compared to MA owners
#MLLW (chart datum)
#territorial sea related to MLLW (12 n. mi.)
#exclusive economic zone related to MLLW (200 n. mi.)

## NOS BENCHMARK LEVELING

- Distances vary but usually several hundred meters.

**Notes:**
NOS uses a double run method
we basically hit each benchmark twice this way the mark is double checked for stability (a.k.a. closure).
Once per year during annual inspection for primary and secondary or before installation and after removal for tertiary.
We’re more interested in the vertical stability than the horizontal.

**Go to PC’s to show how to find this on the net**

## GEOID MODELS

- U.S. NATIONAL MODEL -- GEOID99 (http://www.ngs.noaa.gov/cgi-bin/GEOID_STUFF/geoid99_prompt1.prl)
- CANADIAN NATIONAL MODEL -- GSD95
- http://www.geod.nrcan.gc.ca/products/html-public/GSDinfo/English/factsheets/gpsht_fact.html
- GLOBAL MODEL -- EGM 96
- (http://www.nima.mil/GandG/wgs-84/egm96.html)

## Slide 42

## USGG2003 and GEOID03

USGG = U.S. Gravimetric Geoid
GEOID03 = U.S. Hybrid Geoid

In excess of 11,000 GPS on BMs
(A, B, and 1st- Order GPS on 1st, 2nd and 3rd – Order NAVD 88 BMs)

Possibly overall misfit will be about 2.9 cm.

**USGG = U.S. Gravimetric Geoid**
**GEOID03 = U.S. Hybrid Geoid**
**In excess of 11,000 GPS on BMs**
- (A, B, and 1st- Order GPS on 1st, 2nd and 3rd – Order NAVD 88 BMs)
**Possibly overall misfit will be about 2.9 cm.**

**NEW U.S. GEOID MODEL****Release by January 2004**

## Standalone Positioning: Since May 1, 2000

**C/A Code on L1**
**No Selective Availability**

**6-11 m**

## Standalone Positioning: By 2011

**C/A Code on L1**
**C/A Code on L2**
**New Code on L5**

**1-3 m**

**Better resistance to interference**

## GLOBAL POSITIONING SYSTEM

- GPS BLOCK III
- Potential Future Developments
- 30 - 32 satellites
- Second and Third Civil Frequency
- (1227.60 MHZ & 1176.45 MHZ)
- More Robust Signal Transmissions
- Real-Time Unaugmented  1 Meter Accuracy
- Initial Launches ~ 2005
- Complete Replacements ~ 2015??

## GLOBAL NAVIGATION SATELLITE SYSTEMS(GNSS)

- POTENTIAL FUTURE DEVELOPMENTS
- (2005 – 2015??)
- GPS MODERNIZATION - BLOCK III
- GLONASS ENHANCEMENTS
- EUROPEAN  UNION  - GALILEO
- 70- 90  Satellites
- Second and Third Civil Frequency - GPS
- No Signal Encryption - GLONASS & GALILEO
- More Robust Signal Transmissions
- Real-Time Unaugmented 1 Meter (or better!) Accuracy

## GEODETIC DATA SHEET

** **

**Geodetic Data Sheets**

## GEODETIC DATA SHEET

** **

## GEODETIC DATA SHEET

-   **   ****National Geodetic Survey,   Retrieval Date = NOVEMBER 15, 2003**
** ****BN0540 *************************************************************************
** ****BN0540  FBN         -  This is a Federal Base Network Control Station.**
** ****BN0540  DESIGNATION -  CHERRY**
** ****BN0540  PID         -  BN0540**
** ****BN0540  STATE/COUNTY-  TX/GILLESPIE**
** ****BN0540  USGS QUAD   -  CHERRY SPRING (1967)**
** ****BN0540**
** ****BN0540                         *CURRENT SURVEY CONTROL**
** ****BN0540  ___________________________________________________________________**
** ****BN0540* NAD 83(1993)-  30 29 48.47740(N)    099 00 39.29203(W)     ADJUSTED  **
** ****BN0540* NAVD 88     -       542.733  (meters)    1780.62   (feet)  ADJUSTED  **
** ****BN0540  ___________________________________________________________________**
** ****BN0540  X           -    -861,575.021 (meters)                     COMP**
** ****BN0540  Y           -  -5,433,071.971 (meters)                     COMP**
** ****BN0540  Z           -   3,218,212.963 (meters)                     COMP**
** ****BN0540  LAPLACE CORR-          -2.38  (seconds)                    DEFLEC99**
** ****BN0540  ELLIP HEIGHT-         520.52  (meters)          (05/01/00) GPS OBS**
** ****BN0540  GEOID HEIGHT-         -22.17  (meters)                     GEOID99**
** ****BN0540  DYNAMIC HT  -         541.984 (meters)    1778.16  (feet)  COMP**
** ****BN0540  MODELED GRAV-     979,243.1   (mgal)                       NAVD 88**
** ****BN0540**
** ****BN0540  HORZ ORDER  -  B**
** ****BN0540  VERT ORDER  -  FIRST     CLASS II**
** ****BN0540  ELLP ORDER  -  THIRD     CLASS I**

**            ****H = h - N**
**                       ****542.73 = 520.52 - (- 22.17) **
**     ****542.73 ******** 542.69**

**(EGM96 = - 23.09 m)**

## GEODETIC DATA SHEET

** **

** ****BN0540.The horizontal coordinates were established by GPS observations**
** ****BN0540.and adjusted by the National Geodetic Survey in May 1994.**
** ****BN0540**
** ****BN0540.The orthometric height was determined by differential leveling**
** ****BN0540.and adjusted by the National Geodetic Survey in June 1991.**
** ****BN0540**
** ****BN0540.The X, Y, and Z were computed from the position and the ellipsoidal ht.**
** ****BN0540**
** ****BN0540.The Laplace correction was computed from DEFLEC99 derived deflections.**
** ****BN0540**
** ****BN0540.The ellipsoidal height was determined by GPS observations**
** ****BN0540.and is referenced to NAD 83.**
** ****BN0540**
** ****BN0540.The geoid height was determined by GEOID99.**
** ****BN0540**
** ****BN0540.The dynamic height is computed by dividing the NAVD 88**
** ****BN0540.geopotential number by the normal gravity value computed on the**
** ****BN0540.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45**
** ****BN0540.degrees latitude (g = 980.6199 gals.).**
** ****BN0540**
** ****BN0540.The modeled gravity was interpolated from observed gravity values.**
** ****BN0540**
** ****BN0540;                    North         East     Units   Scale      Converg.**
** ****BN0540;SPC TX C     - 3,092,779.590   826,941.837   MT  0.99992026 +0 40 52.0**
** ****BN0540;UTM  14      - 3,373,836.874   498,952.609   MT  0.99960001 -0 00 19.9**
** ****BN0540**

## GEODETIC DATA SHEET

** ****BN0540:                Primary Azimuth Mark                     Grid Az**
** ****BN0540:SPC TX C     -  CHERRY AZ MK                             183 41 09.7**
** ****BN0540:UTM  14      -  CHERRY AZ MK                             184 22 21.6**
** ****BN0540**
** ****BN0540|---------------------------------------------------------------------|**
** ****BN0540| PID    Reference Object                     Distance      Geod. Az  |**
** ****BN0540|                                                           dddmmss.s |**
** ****BN0540| BN0541 CHERRY RM 2                           7.440 METERS 00148     |**
** ****BN0540| CV4542 CHERRY RM 1                           7.675 METERS 17732     |**
** ****BN0540| BN0539 CHERRY RM 3                           7.710 METERS 17741     |**
** ****BN0540| BN0538 CHERRY AZ MK                                       1842201.7 |**
** ****BN0540| BN0722 LOYAL MTN MICROWE RADIO MAST        APPROX. 9.3 KM 3531351.6 |**
** ****BN0540|---------------------------------------------------------------------|**
** ****BN0540**
** ****BN0540                          SUPERSEDED SURVEY CONTROL**
** ****BN0540**
** ****BN0540  ELLIP H (05/09/94)  520.61   (m)                       GP(       ) 4 2**
** ****BN0540  NAD 83(1986)-  30 29 48.49063(N)    099 00 39.27999(W) AD(       ) 3**
** ****BN0540  NAD 27      -  30 29 47.81630(N)    099 00 38.10070(W) AD(       ) 3**
** ****BN0540  NAVD 88 (05/09/94)  542.73   (m)         1780.6    (f) LEVELING    3  **
** ****BN0540  NGVD 29 (10/23/89)  542.68   (m)         1780.4    (f) LEVELING    3  **
** ****BN0540**
** ****BN0540.Superseded values are not recommended for survey control.**
** ****BN0540.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.**
** ****BN0540.See file dsdata.txt to determine how the superseded data were derived.**

## GEODETIC DATA SHEET

** ****BN0540_U.S. NATIONAL GRID SPATIAL ADDRESS: 14RMU9895373837(NAD 83)**
** ****BN0540_MARKER: DS = TRIANGULATION STATION DISK**
** ****BN0540_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT**
** ****BN0540_STAMPING: CHERRY 1956**
** ****BN0540_MARK LOGO: CGS   **
** ****BN0540_PROJECTION: PROJECTING 12 CENTIMETERS**
** ****BN0540_MAGNETIC: O = OTHER; SEE DESCRIPTION**
** ****BN0540_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO**
** ****BN0540+STABILITY: SURFACE MOTION**
** ****BN0540_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR**
** ****BN0540+SATELLITE: SATELLITE OBSERVATIONS - September 05, 2001**
** ****BN0540**
** ****BN0540  HISTORY     - Date     Condition        Report By**
** ****BN0540  HISTORY     - 1956     MONUMENTED       CGS**
** ****BN0540  HISTORY     - 1969     GOOD             CGS**
** ****BN0540  HISTORY     - 1982     GOOD             NGS**
** ****BN0540  HISTORY     - 19890106 GOOD             NGS**
** ****BN0540  HISTORY     - 19930306 GOOD             NGS**
** ****BN0540  HISTORY     - 19960309 GOOD             USPSQD**
** ****BN0540  HISTORY     - 19980307 GOOD             NGS**
** ****BN0540  HISTORY     - 20010905 GOOD             INDIV**
** ****BN0540**
** ****BN0540                          STATION DESCRIPTION**
** ****BN0540**
** ****BN0540'DESCRIBED BY COAST AND GEODETIC SURVEY 1956 (WFD)**
** ****BN0540'THE STATION IS 0.65 MILE NORTH OF CHERRY SPRINGS, 0.1 MILE**
** ****BN0540'SOUTH OF THE GILLESPIE-MASON COUNTY LINE AND ON THE RIGHT-OF-WAY**
** **

## GEODETIC CONTROL DATA SHEET

**        ****National Geodetic Survey,   Retrieval Date = SEPTEMBER 11, 2003**
** ****TA0047 *************************************************************************
** ****TA0047  DESIGNATION -  G 216**
** ****TA0047  PID         -  TA0047**
** ****TA0047  STATE/COUNTY-  MN/COOK**
** ****TA0047  USGS QUAD   -  LONG ISLAND LAKE (1986)**
** ****TA0047**
** ****TA0047                         *CURRENT SURVEY CONTROL**
** ****TA0047  ___________________________________________________________________**
** ****TA0047* NAD 83(1986)-  48 04 54.20   (N)    090 45 48.42   (W)     HD_HELD1  **
** ****TA0047* NAVD 88     -       512.698  (meters)    1682.08   (feet)  ADJUSTED  **
** ****TA0047  ___________________________________________________________________**
** ****TA0047  GEOID HEIGHT-         -30.65  (meters)                     GEOID99**
** ****TA0047  DYNAMIC HT  -         512.802 (meters)    1682.42  (feet)  COMP**
** ****TA0047  MODELED GRAV-     980,798.7   (mgal)                       NAVD 88**
** ****TA0047**
** ****TA0047  VERT ORDER  -  SECOND    CLASS 0**
** ****TA0047**
** ****TA0047.The horizontal coordinates were established by differentially corrected**
** ****TA0047.hand held GPS obs and have an estimated accuracy of +/- 3 meters.**
** ****TA0047**
** ****TA0047.The orthometric height was determined by differential leveling**
** ****TA0047.and adjusted by the National Geodetic Survey in June 1991.**
** ****TA0047**
** ****TA0047.Photographs are available for this station.**
** ****TA0047**
** ****TA0047;                    North         East    Units  Estimated Accuracy**
** ****TA0047;SPC MN N     -   278,477.4     974,048.5     MT  (+/- 3 meters HH1 GPS) **
** ****TA0047**

**Up dated position by hand held GPS**

## Slide 55

## NAD 83 READJUSTMENT

**ONLY GPS DATA**
**CONTINUOUSLY OPERATING REFERENCE STATIONS **
**FEDERAL BASE NETWORK**
**COOPERATIVE BASE NETWORK**
**USER DENSIFICATION NETWORK**
**LAYERED ADJUSTMENT OF**
**3,000 INDIVIDUAL PROJECTS INLCUDING MORE THAN 59,000 STATIONS**
**BOTH NAD 83(NSRS) AND ITRF COORDINATES WILL BE PUBLISHED**

**NAD 83 READJUSTMENT**

## NETWORK READJUSTMENTS

- NAD 83 data that is _**NOT**_ part of NSRS must be readjusted by contractor/user with original observations

## NEW STANDARDS FOR GEODETIC CONTROL

**                  ****Two accuracy standards**
- (http://fgdc.er.usgs.gov/standards/status/swgstat.html)
-    local accuracy  -------------   adjacent points
-    network accuracy ----------   relative to CORS
- Numeric quantities, units in cm (or mm)
- Both are relative accuracy measures
- Do not use distance dependent expression
- Horizontal accuracies are radius of 2-D 95% error circle
- Ellipsoidal/Orthometric heights are 1-D (linear) 95% error

## CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

-   Installed and Operated by various Federal-State-local Agencies
- NOAA/National Geodetic Survey
- NOAA/OAR  Forecast Systems Lab
- U.S. Coast Guard - DGPS/NDGPS
- Corps of Engineers - DGPS
- FAA -  WAAS/LAAS (Future)
- State DOTs
- County and City
- Academia
- Private Companies

**CHL1 - CAPE HENLOPEN, DE**

## CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

- Variety of “Geodetic  Quality” Dual-Frequency
-  Antennas and Receivers
-          **Allen-Osborne**
-         **Ashtech/Thales **
**               ****Leica**
**               ****Trimble**

**CHL1 - CAPE HENLOPEN, DE**

## CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

- Some stations provide real-time code phase observations
- 1-5 - 15 - 30” post-process carrier phase observations
- Free access via Internet (RINEX-2 Format)
- More than 425 Station National Network

## CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)

- _NGS PROVIDES_
- Reference Site Survey Monumentation
- Horizontal and Vertical NSRS Connections
- NAD 83, ITRF94, ITRF96, ITRF97, ITRF00 Coordinates
- Network Data Collection - Hourly & Daily
- Daily 3D Network Integrity Adjustment
- Public Data Distribution - Internet
- (http://www.ngs.noaa.gov/CORS/cors-data.html)
- 9 Year On-Line Data Holding

## Slide 63

## Slide 64

## Slide 65

##  ***ITRF 00***

** *******ITRF 00*****
** ****HOUSTON RRP2 (TXHU),  TEXAS**
** ****Retrieved from NGS DataBase on 11/15/03 at 14:14:49.**
** ****____________________________________________________________________________ **
**|                                                                            |**
**|         Antenna Reference Point(ARP): HOUSTON RRP2 CORS ARP                |**
**|         ---------------------------------------------------                |**
**|                             PID = DF4379                                   |**
**|                                                                            |**
**|                                                                            |**
**| ITRF00 POSITION (EPOCH 1997.0)                                             |**
**| Computed in Mar., 2003 using 13 days of data.                              |**
**|     X =   -524578.515 m     latitude    =  29 46 45.91022 N                |**
**|     Y =  -5515562.145 m     longitude   = 095 25 58.76631 W                |**
**|     Z =   3149180.614 m     ellipsoid height =   12.001   m                |**
**|                                                                            |**
**| ITRF00 VELOCITY                                                            |**
**| Set equal to vel of hous Mar., 2003.                                       |**
**|     VX =  -0.0145 m/yr      northward =  -0.0045 m/yr                      |**
**|     VY =   0.0096 m/yr      eastward  =  -0.0153 m/yr                      |**
**|     VZ =  -0.0099 m/yr      upward    =  -0.0120 m/yr                      |**
**|                                                                            |**
**|                                                                            |**
**| NAD_83 POSITION (EPOCH 2002.0)                                             |**
**| Transformed from ITRF00 (epoch 1997.0) position in Mar., 2003.             |**
**|     X =   -524577.977 m     latitude    =  29 46 45.89147 N                |**
**|     Y =  -5515563.571 m     longitude   = 095 25 58.74137 W                |**
**|     Z =   3149180.732 m     ellipsoid height =   13.247   m                |**
**|                                                                            |**
**| NAD_83 VELOCITY                                                            |**
**| Transformed from ITRF00 velocity in Mar., 2003.                            |**
**|     VX =  -0.0008 m/yr      northward =  -0.0002 m/yr                      |**
**|     VY =   0.0108 m/yr      eastward  =  -0.0018 m/yr                      |**
**|     VZ =  -0.0063 m/yr      upward    =  -0.0124 m/yr                      |**
**|____________________________________________________________________________|**

## CORS DATA QUALITY

## IGS Tracking Network

**IGS Tracking Network**

**http://igscb.jpl.nasa.gov/**

## OPUS – WHAT IS IT?

- _O_n-line _P_ositioning _U_ser _S_ervice
- Provide GPS users faster & easier access to the National Spatial Reference System (NSRS)

## OPUS – HOW DOES IT WORK?

- Submit RINEX file through NGS web page
- Processed automatically with  NGS computers & software
- With respect to 3 suitable or user-selected National CORS
- Solution via email in minutes

## OPUS – HOW DO I USE IT?

- Go to OPUS web page   www.ngs.noaa.gov/OPUS
- Enter your email address
- Use browse feature to select RINEX file on your computer
- Select antenna type from menu
- Enter antenna height in meters
- Option to select State Plane Zone
- Click UPLOAD
- Check your email in a few minutes

## Slide 72

## Slide 73

## DATUM TRANSFORMATIONS

- 1. WHAT DATUM ARE THE EXISTING COORDINATES ON?
- 2. WHAT DATUM DO I WANT THE NEW COORDINATES ON?
- 3.  HOW LARGE A GEOGRAPHICAL AREA DO I WANT TO CONVERT               	AT ONE TIME?
- 4.  HOW MANY POINTS ARE COMMON TO BOTH DATUMS?
- 5.  WHAT IS THE DISTRIBUTION OF THE COMMON POINTS?
- 6.  HOW ACCURATE ARE THE EXISTING COORDINATES?
-         0.1 Foot
- 1.0 Foot
- 10. Feet
- 7.  HOW ACCURATE DO I WANT THE NEW COORDINATES?

## DATUM TRANSFORMATIONS

- MOLODENSKY
- Converts latitude, longitude and ellipsoidal height  to X,Y,Z Earth-Centered Coordinates.
- Applies a 3-dimensional change in the origin (dX, dY,dZ)
- Applies a change in the size and shape of the reference ellipsoid
- Converts new X,Y,Z Earth-Centered Coordinates back to latitude,  longitude and ellipsoidal height

## DATUM TRANSFORMATIONS

- MOLODENSKY
- For continental regions accuracy can  be  +/-  8  to 10 meters
- Does not model network distortions very well.
- Assumes heights in both systems are ellipsoidal (NAD 27 did not have ellipsoidal heights).

## X

**X**

**Z**

**Y**

- A

- XA

- YA

- ZA

- Equator

- Greenwich
- Meridian

- Earth-Centered Earth-Fixed
-               (ECEF)
-      Coordinate System

- Earth
- Mass Center

- - X

- - Y

- - Z

**(X,Y,Z,)**

**Latitude**
**Longitude**
**Ellipsoid Height**

## X

**X**

**Z**

**Y**

- Earth-Centered Earth-Fixed
-               (ECEF)
-      Coordinate System

**Z**

**Y**

**X**

## dX

- dY

- dZ

- 3 Parameter Molodensky Transformation
-                  “In The Real World”

**I NEED TO TRANSFORM****BETWEEN NAD 27 AND WGS 84**

**I NEED TO TRANSFORM****BETWEEN NAD 27 AND WGS 84**

## MOLODENSKY TRANSFORMATION

- _COMPUTED vs. MODELED_
- Station:  CHERRY
- _NAD 27_		         _NAD 83(1992) _                    _dX, dY,dZ_
-          X =       -861,565.807 m	       X =    - 861,575.021** **m             - 9.214 m
- Y = - 5,433,217.188 m              Y = - 5,433,071.971** **m        + 145.217 m
- Z =  +3,218,031.876 m              Z = + 3,218,212.963** **m       + 181.087 m
- _COMPUTED_               _NIMA EAST_              	_NIMA CONUS_
- dX = - 9 m                     dX = -9 (0 m)              	dX = -8 (1m)
- dY = + 145                    dY = + 161 (16 m)    	dY = + 160 (15 m)
- dZ = + 181                    dZ = + 179 (2 m)        	dZ = + 176 (5 m)

## DATUM TRANSFORMATION IDEAL METHOD

-   SATISFIES ALL USERS’ REQUIREMENTS
- CAPABLE OF TRANSFORMING LARGE HOLDINGS OF COORDINATE DATA
- NEAR-REAL TIME APPLICATIONS
- SIMPLE - METHOD SHOULD NOT REQUIRE AN EXPERT OR DECISIONS TO BE MADE
- ACCURATE

## NADCON

- DESIGNED TO SATISFY THE MAJORITY OF THE “IDEAL METHOD” DESIGN AND HAS DEFINED AS THE NATIONAL STANDARD.
- DESIGN CRITERIA:
- Relies only on NGS archived data existing in both NAD 27 and NAD 83
- Provides consistent results, both forward and inverse
- Fast
- Not tied to NGS Data Base
- Small - Fit on PC
- Accurate
-   15 cm (1 sigma) in Conterminous U.S.  NAD 27 - NAD 83(1986)
-   5 cm (1 sigma) per State/Region NAD 83 (1986) - HARN

## NADCON

******= +0.12344**
****** ****=  -1.87842**

******= +0.12249**
****** ****=  -1.88963**

******= +0.12423**
****** ****=  -1.81246**

******= +0.12568**
****** ****=  -1.83364**

******= +0.12449**
****** ****=  -1.88905**

******= +0.12499**
****** ****=  -1.86543**

******= +0.12640**
****** ****=  -1.85407**

##  COORDINATE TRANSFORMATION COMPARISONNAD 27 to NAD 83(1992)

- MOLODENSKY
- _ADJUSTED vs. TRANSFORMED_
- Station:  CHERRY
-                                  _LATITUDE_                _LONGITUDE_
-                                 30-29- 48.47740        099-00-39.29203 - PUBLISHED
-                                 _30-29-48.67650_         _099-00-39.37955_ - MOLODENSKY
-                                                .19910”                       .08752”
-                                              6.131 m                      2.334 m
- THIS CORRESPONDS TO A POSITIONAL
- DIFFERENCE OF _6.560_ m  (21.52 ft)

##      COORDINATE TRANSFORMATION COMPARISON    NAD 27 to NAD 83(1992)

- NADCON
- (ftp://ftp.ngs.noaa.gov/pub/pcsoft/nadcon/)
- _ADJUSTED vs. TRANSFORMED_
- Station: CHERRY
-                                               _LATITUDE_         _LONGITUDE_
- 	             30-29-48.47740     099-00-39.29203 - PUBLISHED
-                     _30-29-48.48670_      _099-00-39.28787 _ - NADCON
-                                                 .00930”                    .00416”
-                                                     0.286 m                   0.111 m
-       THIS CORRESPONDS TO A POSITIONAL
- DIFFERENCE OF _0.307 _m  (1.01 ft)

## GPS NETWORKS TO SUPPORT GIS

- “CLASSICAL”
- Lots of control points spaced at regular intervals
- (1-3 miles)
- “CONTEMPORARY”
- CORS and Monumentation as needed

## GPS NETWORKS TO SUPPORT GIS

**OBSERVE TO NATIONAL STANDARDS**
**TIES TO CORS, HARN and LOCAL BMs**
**QUALITY MONUMENTATION**

## GPS NETWORKS TO SUPPORT GIS CLASSICAL

## GPS NETWORKS TO SUPPORT GIS CONTEMPORARY

## CLASSICAL GPS NETWORKS

**PROS**
- Monumentation usually established in only 1 or 2  GPS survey campaigns
- Complete coverage
- No time lag for users access to control
**CONS**
- Large initial cost
- Continual network maintenance
- Monumentation destroyed or disturbed before they’re used

## CONTEMPORARY GPS NETWORKS

**PROS**
- Minimal “permanent” monumentation
- Project control established when and where needed
- Costs spread over time
**CONS**
- Qualified staff to coordinate user requirements
- Time lag to establish project control

## GPS NETWORKS TO SUPPORT GIS

**GPS SURVEY DATA**
- “BLUE - BOOK” SUBMISSION OF DATA FOR
- INCLUSION IN NSRS
- OR
- DATA MAINTAINED AT THE LOCAL LEVEL

## GPS NETWORKS TO SUPPORT GIS“BLUE-BOOK”

**PROS**
- DATA MAINTAINED IN NSRS IN PERPETUTITY
- PROVIDES IMPROVED DATA FOR FUTURE NATIONAL GEOID MODELS
- UNIVERSAL DATA ACCESS VIA NGS WEB SITE
- “GOOD HOUSEKEEPING SEAL OF APPROVAL”
**CONS**
- INCREASED INITIAL COST (15 - 20%)
- SLIGHT INCREASE IN INITIAL DATA PROCESSING TIME

## GPS NETWORKS TO SUPPORT GISLOCAL MAINTENANCE

**PROS**
- DECREASED INITIAL SURVEY COSTS
- LOCAL CONTROL OF ALL DATA
**CONS**
- READJUSTMENTS TO FUTURE REFERENCE FRAME CHANGES MUST BE DONE AT THE LOCAL LEVEL
- DATA MAY BE DIFFICULT TO LOCATE FOR “NON-LOCALS”
- DATA DOES NOT CONTRIBUTE TO FUTURE NATIONAL GEOID MODELS

## GOOD COORDINATION BEGINS WITH 

**GOOD COORDINATION BEGINS WITH **
**GOOD COORDINATES**

**GEOGRAPHY WITHOUT GEODESY IS A FELONY**