development, implementation and future of the national spatial reference system
DESCRIPTION
DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM PROFESSIONAL LAND SURVEYORS OF OHIO TOLEDO FEBRUARY 11, 2000 David Doyle National Geodetic Survey 301-713-3178 [email protected]. NATIONAL GEODETIC SURVEY. INFORMATION CENTER (301) 713-3242. WEB SITE - PowerPoint PPT PresentationTRANSCRIPT
DEVELOPMENT, IMPLEMENTATIONAND FUTURE OF THE NATIONAL SPATIAL
REFERENCE SYSTEM
PROFESSIONAL LAND SURVEYORS OF OHIOTOLEDO
FEBRUARY 11, 2000
David DoyleNational Geodetic Survey
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 OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
THE ELLIPSOID
b
a
a = Semi major axis b = Semi minor axis f = a-b = Flattening a
N
S
NATIONAL OCEAN SERVICE
ELLIPSOID DEFINITIONS
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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)
NATIONAL OCEAN SERVICE
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!!!!!
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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)
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
PX,Y,Z
NAD 83 and ITRF
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
NAD 83 NETWORK PROBLEMS
NOT “GPSABLE”
POOR STATION ACCESSIBILITY
IRREGULARLY SPACED
POSITIONAL ACCURACY
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
HIGH ACCURACY REFERENCE NETWORKS
NATIONAL OCEAN SERVICE
USER DENSIFICATION NETWORK
FEDERAL-STATE-LOCAL FUNDING
STATION SPACING AS REQUIRED
GPS OBSERVATIONS ONLY (HORIZONTAL)
FIRST-ORDER HORIZONTAL ACCURACY
REVISIT AS NEEDED
NATIONAL OCEAN SERVICE
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)]
NATIONAL OCEAN SERVICE
HARN ADJUSTMENT
NAD 83 Data that is NOT Part of NSRS must
be readjusted by contractor/user with original observations
NATIONAL OCEAN SERVICE
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)
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
NAD 83 READJUSTMENT
WILL NOT INCLUDE OLD CONVENTIONAL OBSERVATIONS
TRIANGULATION
TRAVERSE
TRILATERATION
INERTIAL
PHOTOGRAMMETRY
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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?
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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).
NATIONAL OCEAN SERVICE
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
NATIONAL OCEAN SERVICE
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/)
ADJUSTED vs. TRANSFORMED
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
ADJUSTED vs. TRANSFORMED
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
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)
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)
NATIONAL OCEAN SERVICE
CHL1 - CAPE HENLOPEN, DE
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)
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
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)
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
NATIONAL OCEAN SERVICE
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 | |____________________________________________________________________________|
CONTINUOUSLY OPERATING REFERENCE STATIONS (CORS)
GOOD COORDINATION BEGINS WITH GOOD COORDINATES
GEOGRAPHY WITHOUT GEODESY IS A FELONY