DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM

DEVELOPMENT, IMPLEMENTATIONAND FUTURE OF THE NATIONAL SPATIAL

REFERENCE SYSTEM

PROFESSIONAL LAND SURVEYORS OF OHIOTOLEDO

FEBRUARY 11, 2000

David DoyleNational Geodetic Survey

[email protected]

NATIONAL GEODETIC SURVEY

INFORMATION CENTER

(301) 713-3242

NATIONAL OCEAN SERVICE

WEB SITEhttp://www.ngs.noaa.gov

INTERESTING WEB SITES

GIS/GPS/RS Web Forum http://www.ggrweb.com/webbbs.html

The On-Line Resource for Professional Land Surveyors http://rpls.com


NATIONAL SPATIAL REFERENCE SYSTEM

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), observed by NGS as well as data submitted by other Federal, State, and local agencies, Academic Institutions and the private sector


METADATA

METADATA IS DATA ABOUT DATA DATUMS

NAD 27, NAD 83(1986), NAD83 (199X), NGVD29,NAVD88

UNITS Meters, U.S. Survey Feet, International Feet, Chains, Rods, Pole

ACCURACY

A, B, 1st, 2nd, 3rd, 3cm, Scaled


THE ELLIPSOID

b

a

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

N

S


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

ELLIPSOID - GEOID RELATIONSHIP

H h

EllipsoidGRS80

H = Orthometric Height

N

GeoidGEOID99

H = h - N

PERPENDICULAR TO ELLIPSOID

PERPENDICULARTO GEOID (PLUMBLINE) DEFLECTION OF THE VERTICAL

DEFLEC99

TOPOGRAPHIC SURFACE

h = Ellipsoidal HeightN = Geoid Height

THE GEOID AND TWO ELLIPSOIDS


GRS80-WGS84CLARKE 1866

GEOID

Earth Mass Center

Approximately 236 meters

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)


NO SPCS EXISTING NAD 27 ENACTED NAD 83 SPC

LEGISLATION LEGISLATION LEGISLATION

(4) (3) (45)

District of Columbia Alabama Alaska Maryland (S) Oklahoma (S) Hawaii Arkansas Arizona (I) Massachusetts (S) Oregon (I) Nebraska Illinois California (S) Michigan (I) Pennsylvania (S) Puerto Rico Colorado (S) Minnesota Rhode Island Connecticut (S) Mississippi (S) South Carolina (I) I = International Feet and Meters Delaware(S) Missouri South Dakota 1 m = 3.280839895 feet Florida (S) Montana Tennessee (S) S = U.S. Survey Feet and Meters Georgia (S) Nevada Texas (S) 1 m = 3.280833333 feet Idaho (S) New Hampshire Utah (I)

Indiana (S) New Jersey Vermont

Iowa New Mexico (S) Virginia (S) Kansas New York (S) Washington

(S) Kentucky (S) North Carolina (S) West Virginia Louisiana North Dakota (I) Wisconsin (S) Maine Ohio Wyoming

STATUS OF NAD 27 AND NAD 83 STATE PLANE COORDINATE LEGISLATION - AUGUST 1999

GROUND LEVEL COORDINATES

“I WANT STATE PLANE COORDINATES RAISED TO GROUND LEVEL”

GROUND LEVEL COORDINATES ARE NOT STATE PLANE COORDINATES!!!!!


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)

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


WORLD GEODETIC SYSTEM 1984

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)

DoD World Geodetic System 1984 - Its Definition and Relationships with Local

Geodetic Systems (also: http://164.214.2.59/GandG/pubs.html)

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)


GEOID MODELS

OSU 78

OSU 89B

GEOID 90

GEOID 93

GEOID 96

GEOID 99

GEOID2000??? NATIONAL OCEAN SERVICE

GEODETIC CONTROL

NETWORK OF MONUMENTED POINTS

PRECISELY MEASURED IN ACCORDANCE

WITH STANDARD PROCEDURES

MEET ACCURACY SPECIFICATIONS

ADJUSTED TO TIE TOGETHER

DOCUMENTED FOR MULTIPLE USENATIONAL OCEAN SERVICE

GEODETIC CONTROL DATA SHEET 1 National Geodetic Survey, Retrieval Date = DECEMBER 20, 1999 *********************************************************************** KZ2107 CBN - This is a Cooperative Base Network Control Station. KZ2107 DESIGNATION - BLACK KZ2107 PID - KZ2107 KZ2107 STATE/COUNTY- OH/HANCOCK KZ2107 USGS QUAD - RAWSON (1973) KZ2107 KZ2107 *CURRENT SURVEY CONTROL KZ2107 ___________________________________________________________________ KZ2107* NAD 83(1995)- 40 53 34.00022(N) 083 49 24.71990(W) ADJUSTED KZ2107* NAVD 88 - 260.760 (meters) 855.51 (feet) ADJUSTED KZ2107 ___________________________________________________________________ KZ2107 X - 519,510.204 (meters) COMP KZ2107 Y - -4,800,536.269 (meters) COMP KZ2107 Z - 4,153,576.907 (meters) COMP KZ2107 LAPLACE CORR- -0.92 (seconds) DEFLEC99 KZ2107 ELLIP HEIGHT- 225.44 (meters) GPS OBS KZ2107 GEOID HEIGHT- -35.31 (meters) GEOID99 KZ2107 DYNAMIC HT - 260.630 (meters) 855.08 (feet) COMP KZ2107 MODELED GRAV- 980,118.4 (mgal) NAVD 88 KZ2107 KZ2107 HORZ ORDER - B KZ2107 VERT ORDER - FIRST CLASS II KZ2107 ELLP ORDER - FOURTH CLASS II

H = h - N260.76 = 225.44 - (-35.31)260.76 == 260.75 ????

GEODETIC CONTROL DATA SHEET KZ2107: Primary Azimuth Mark Grid Az KZ2107:SPC OH N - BLACK AZ MK 357 30 36.3 KZ2107:UTM 17 - BLACK AZ MK 358 29 23.5 KZ2107 KZ2107|---------------------------------------------------------------------| KZ2107| PID Reference Object Distance Geod. Az | KZ2107| dddmmss.s | KZ2107| KZ2433 BLACK RM 1 35.357 METERS 08749 | KZ2107| KZ2434 BLACK RM 2 42.431 METERS 18658 | KZ2107| KZ2420 BLACK AZ MK 3563826.1 | KZ2107|---------------------------------------------------------------------| KZ2107 KZ2107 SUPERSEDED SURVEY CONTROL KZ2107 KZ2107 NAD 83(1986)- 40 53 34.00969(N) 083 49 24.73216(W) AD( ) 1 KZ2107 NAD 83(1986)- 40 53 34.01022(N) 083 49 24.73374(W) AD( ) 1 KZ2107 NAD 27 - 40 53 33.82300(N) 083 49 24.96100(W) AD( ) 1 KZ2107 NGVD 29 - 260.89 (m) 855.9 (f) LEVELING 3 KZ2107 KZ2107.Superseded values are not recommended for survey control. KZ2107.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums. KZ2107.See file dsdata.txt to determine how the superseded data were derived.

GEODETIC CONTROL DATA SHEET KZ2107_MARKER: DS = TRIANGULATION STATION DISK KZ2107_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT KZ2107_STAMPING: BLACK 1943 KZ2107_MAGNETIC: N = NO MAGNETIC MATERIAL KZ2107_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO KZ2107+STABILITY: SURFACE MOTION KZ2107_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR KZ2107+SATELLITE: SATELLITE OBSERVATIONS - August 07, 1995 KZ2107 HISTORY - Date Condition Recov. By KZ2107 HISTORY - 1943 MONUMENTED CGS KZ2107 HISTORY - 1943 GOOD CGS KZ2107 HISTORY - 1957 GOOD CGS KZ2107 HISTORY - 1960 GOOD CGS KZ2107 HISTORY - 1986 GOOD NGS KZ2107 HISTORY - 19870917 GOOD KZ2107 HISTORY - 19891212 GOOD OHDT KZ2107 HISTORY - 19900220 GOOD KZ2107 HISTORY - 19930712 GOOD NGS KZ2107 HISTORY - 19940822 GOOD OH-063 KZ2107 HISTORY - 19950807 GOOD NGS KZ2107 STATION DESCRIPTION KZ2107'DESCRIBED BY COAST AND GEODETIC SURVEY 1943 (APR) KZ2107'STATION IS LOCATED ABOUT 3.9 MILES E OF BLUFFTON IN THE NE ANGLE OF KZ2107'THE INTERSECTION OF STATE HIGHWAYS 103 AND 69. THE MARK IS SET IN THE NE

GEODETIC CONTROL DATA SHEET KZ2107.The horizontal coordinates were established by GPS observations KZ2107.and adjusted by the National Geodetic Survey in August 1996. KZ2107 KZ2107.The orthometric height was determined by differential leveling KZ2107.and adjusted by the National Geodetic Survey in January 1994. KZ2107 KZ2107.The X, Y, and Z were computed from the position and the ellipsoidal ht. KZ2107 KZ2107.The Laplace correction was computed from DEFLEC99 derived deflections. KZ2107 KZ2107.The ellipsoidal height was determined by GPS observations KZ2107.and is referenced to NAD 83. KZ2107 KZ2107.The geoid height was determined by GEOID99. KZ2107 KZ2107.The dynamic height is computed by dividing the NAVD 88 KZ2107.geopotential number by the normal gravity value computed on the KZ2107.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 KZ2107.degrees latitude (G = 980.6199 gals.). KZ2107 KZ2107.The modeled gravity was interpolated from observed gravity values. KZ2107 KZ2107; North East Units Scale Converg. KZ2107;SPC OH N - 137,000.703 488,474.571 MT 0.99994378 -0 52 10.2 KZ2107;UTM 17 - 4,530,692.991 262,138.188 MT 1.00029643 -1 50 57.4•

Autonomous Positioning: Today

• C/A Code on L1• Selective Availability

25-100 m25-100 mHORIZONTAL = 100 meters

VERTICAL = 156 meters1996 Federal Radionavigation PlanSection A2-1, Part Bhttp://www.navcen.uscg.mil/policy/frp1996

Standalone Positioning: By 2006

• C/A Code on L1• No Selective Availability

6-11 m6-11 m

GLOBAL POSITIONING SYSTEM

GPS BLOCK IIF Potential Future Developments

http://206.65.196.30/gps/issues/dotgpspressreleases.htm

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 ~ 2011


GLOBAL NAVIGATION SATELLITE SYSTEMS(GNSS)

POTENTIAL FUTURE DEVELOPMENTS

(2004 - 2011)

US GPS MODERNIZATION - BLOCK IIF

RUSSIAN GLONASS ENHANCEMENTS

EUROPEAN UNION - GALILEO

60+ Satellites

Second and Third Civil Frequency - GPS

No Signal Encryption - GLONASS & GALILEO

More Robust Signal Transmissions

Real-Time Unaugmented 1 Meter (or better!) Accuracy NATIONAL OCEAN SERVICE

Standalone Positioning: By 2011

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

1-3 m1-3 m

Better Better resistance to resistance to interferenceinterference

INTERNATIONAL TERRESTRIALREFERENCE FRAME


DEVELOPED AND MAINTAINED BY THE INTERNATIONAL EARTH ROTATION SERVICE

PARIS, FRANCE FROM:(http://hpiers.obspm.fr/)

VERY LONG BASELINE INTERFEROMETRY - (VLBI)SATELLITE LASER RANGING - (SLR)

GLOBAL POSITIONING SYSTEM - (GPS)DOPPLER ORBITOGRAPHY AND RADIO POSITIONING

INTEGRATED BY SATELLITE - (DORIS)

INTERNATIONAL TERRESTRIALREFERENCE FRAME

GEOCENTRIC +/- 3 to 4 CM

MODELS FOR PLATE TECTONICS

STATION VELOCITIES

POSITIONAL STANDARD ERRORS

USUALLY BI-ANNUAL PUBLICATIONNATIONAL OCEAN SERVICE

CONVENTIONAL TERRESTRIAL SYSTEM(CTS)

Z CTS

YCTSXCTS XY

Z

GreenwichMeridian

Equator

EarthMass Center


PX,Y,Z

NAD 83 and ITRF


ITRFNAD 83

Earth Mass Center

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

GEOID

ITRF96 (Epoch 1998.0) to NAD83ftp://ftp.ngs.noaa.gov/pub/pcsoft/htdp/

X = 0.9910 meters Y = -1.9072 meters Z = -0.5129 meters

rX = 0.02579 seconds

rY = 0.00965 seconds

rZ = 0.01166 seconds

Scale = 0.0 ppmNATIONAL OCEAN SERVICE

ITRF94 (Epoch 1995.0) to NAD83 ftp://ftp.ngs.noaa.gov/pub/pcsoft/htdp/

X = 0.9769 meters Y = -1.9392 meters Z = -0.5461 meters

rX = 0.02640 seconds rY = 0.01010 seconds rZ = 0.01030 seconds

Scale = 0.0 ppm


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)NATIONAL OCEAN SERVICE

FEDERAL BASE NETWORK

NGS FUNDED

NGS MARK MAINTENANCE

MAXIMUM 100 KM STATION SPACING

A and B-ORDER HORIZONTAL ACCURACY

FIRST-ORDER CLASS II ORTHOMETRIC HEIGHTS

or

SECOND-ORDER CLASS I ORTHOMETRIC HEIGHTS

SECOND-ORDER CLASS I ELLIPSOIDAL HEIGHTS

REVISIT EVERY 3 TO 5 YEARS


COOPERATIVE BASE NETWORK

STATE/LOCAL FUNDED

STATE/LOCAL MARK MAINTENANCE

25 TO 30 KM STATION SPACING

B-ORDER HORIZONTAL ACCURACY

THIRD-ORDER CLASS I ORTHOMETRIC HEIGHTS

THIRD-ORDER CLASS I ELLIPSOIDAL HEIGHTS

REVISIT AS NECESSARY


HIGH ACCURACY REFERENCE NETWORKS


USER DENSIFICATION NETWORK

FEDERAL-STATE-LOCAL FUNDING

STATION SPACING AS REQUIRED

GPS OBSERVATIONS ONLY (HORIZONTAL)

FIRST-ORDER HORIZONTAL ACCURACY

REVISIT AS NEEDED


HARN ADJUSTMENT

A-Order Adjusted to VLBI-Existing FBN-CORS

B-Order Adjusted to A-Order

Existing Horizontal (Conventional & GPS) Readjusted

to A/B-Order

New Adjustment Date Tag e.g. NAD 83(1995)

[e.g. Michigan = NAD 83 (1994), Indiana = NAD 83 (1997)]


HARN ADJUSTMENT

NAD 83 Data that is NOT Part of NSRS must

be readjusted by contractor/user with original observations


NAD 83 READJUSTMENT

HARN COMPLETION - SEPTEMBER 1997

(Indiana)

GPS HEIGHT MODERNIZATION OBSERVATIONS

(1997 - 2002?)

(Ohio not yet scheduled) (http://www.ngs.noaa.gov/initiatives/height_modernization.shtml)

COMPLETE GPS NAD 83 3-D ADJUSTMENT (http://www.ngs.noaa.gov/initiatives/new_reference.shtml)

(2002?)

REMOVAL OF SMALL REGIONAL DISTORTIONS

(3 - 6 CM)

UNIFORM COORDINATE TAG

NAD 83 (NSRS02)


NAD 83 READJUSTMENT

NAD 83 READJUSTMENT

ONLY GPS DATA

CONTINUOUSLY OPERATING REFERENCE STATIONS

FEDERAL BASE NETWORK

COOPERATIVE BASE NETWORK

AIRPORT SURVEYS

USER DENSIFICATION NETWORK

SPECIAL SURVEYS


NAD 83 READJUSTMENT

WILL NOT INCLUDE OLD CONVENTIONAL OBSERVATIONS

TRIANGULATION

TRAVERSE

TRILATERATION

INERTIAL

PHOTOGRAMMETRY


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


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?



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



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).


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 NATIONAL OCEAN SERVICE

COORDINATE COMPARISONNAD 27 to NAD 83(1986)

MOLODENSKY (http://164.214.2.59/GandG/pubs.html)

ADJUSTED vs. TRANSFORMED

Station: BLACK

LATITUDE LONGITUDE 40-53-34.00969 083-49-24.73216 - PUBLISHED 40-53-33.99714 083-49-24.60329 - MOLODENSKY .01255” .12887” 0.387 m 3.017 m

THIS CORRESPONDS TO A POSITIONAL

DIFFERENCE OF 3.042 m (9.98 ft)

COORDINATE COMPARISON NAD 27 to NAD 83(1986)

NADCON (ftp://ftp.ngs.noaa.gov/pub/pcsoft/nadcon/)


Station: BLACK

LATITUDE LONGITUDE

40-53-34.00969 083-49-24.73216 - PUBLISHED 40-53-34.01279 083-49-24.73591 - NADCON .00310” .00375” .096 m .130 m

THIS CORRESPONDS TO A POSITIONAL DIFFERENCE OF 0.162 m (0.53 ft)

COORDINATE COMPARISON NAD 83 (1986) to NAD 83(1995)

NADCON


Station: BLACK

LATITUDE LONGITUDE

40-53-34.00022 083-49-24.71990 - PUBLISHED 40-53-34.00137 083-49-24.72151 - NADCON .00115” .00161” .036 m .038 m

THIS CORRESPONDS TO A POSITIONAL DIFFERENCE OF 0.052 m (0.17 ft)

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 CompaniesNATIONAL OCEAN SERVICE

CHL1 - CAPE HENLOPEN, DE


Variety of “Geodetic Quality” Dual-Frequency

Antennas and Receivers

Allen-Osborne (SNR 8000 & SNR 12 ACT)

Ashtech (Z XII3)

Leica (SR9500 & CRS1000)

Trimble (4000SSE & 4000SSI)


CHL1 - CAPE HENLOPEN, DE


Some stations provide real-time code phase observations

5 - 15 - 30” post-process carrier phase observations

Free access via Internet (RINEX-2 Format)

More than 170 Station National Network NATIONAL OCEAN SERVICE


NGS PROVIDES Reference Site Survey Monumentation

Horizontal and Vertical NSRS Connections

NAD 83, ITRF94, ITRF96, ITRF97 Coordinates

Network Data Collection - Hourly & Daily

Daily 3D Network Integrity Adjustment

Public Data Distribution - Internet

(http://www.ngs.noaa.gov/CORS/cors-data.html)

2 Years On-Line Data Holding


CORS DATA SHEET

***ITRF 96***

DETROIT 1 (DET1), MICHIGAN

Retrieved from NGS DataBase on 09/28/98 at 08:38:44. ____________________________________________________________________________ | | | Antenna Reference Point(ARP): DETROIT 1 CORS ARP | | ------------------------------------------------ | | PID = AF9501 | | | | | | ITRF96 POSITION (EPOCH 1997.0) | | Computed in Mar., 1998 using 47 days of data. | | X = 568024.755 m latitude = 42 17 50.45437 N | | Y = -4690674.635 m longitude = 083 05 43.06542 W | | Z = 4270188.820 m ellipsoid height = 145.045 m | | | | ITRF96 VELOCITY | | Computed in Mar., 1998 using 47 days of data. | | VX = -0.0156 m/yr northward = -0.0035 m/yr | | VY = -0.0043 m/yr eastward = -0.0160 m/yr | | VZ = -0.0026 m/yr upward = 0.0000 m/yr | | |

CORS DATA SHEET DETROIT 1 (DET1), MICHIGAN

Retrieved from NGS DataBase on 09/28/98 at 08:38:44. ____________________________________________________________________________

| | | Antenna Reference Point(ARP): DETROIT 1 CORS ARP | | ------------------------------------------------ | | PID = AF9501 | | | | | | | | NAD_83 POSITION (EPOCH 1997.0) | | Transformed from ITRF94 (epoch 1996.00) position. | | X = 568025.282 m latitude = 42 17 50.42503 N | | Y = -4690676.035 m longitude = 083 05 43.04995 W | | Z = 4270188.918 m ellipsoid height = 146.185 m | | | | NAD_83 VELOCITY | | Predicted with HTDP_2.0 in Apr., 1996. | | VX = 0.0000 m/yr northward = 0.0000 m/yr | | VY = 0.0000 m/yr eastward = 0.0000 m/yr | | VZ = 0.0000 m/yr upward = 0.0000 m/yr | |____________________________________________________________________________|

GOOD COORDINATION BEGINS WITH GOOD COORDINATES

GEOGRAPHY WITHOUT GEODESY IS A FELONY

DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM

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Transcript of DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM