1 / 64

DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM

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 daved@ngs.noaa.gov. NATIONAL GEODETIC SURVEY. INFORMATION CENTER (301) 713-3242. WEB SITE

edward-powell
Télécharger la présentation

DEVELOPMENT, IMPLEMENTATION AND FUTURE OF THE NATIONAL SPATIAL REFERENCE SYSTEM

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 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 daved@ngs.noaa.gov

  2. NATIONAL GEODETIC SURVEY • INFORMATION CENTER • (301) 713-3242 WEB SITE http://www.ngs.noaa.gov NATIONAL OCEAN SERVICE

  3. 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

  4. 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

  5. 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

  6. THE ELLIPSOID N b a S a = Semi major axis b = Semi minor axis f = a-b = Flattening a NATIONAL OCEAN SERVICE

  7. ELLIPSOID DEFINITIONS BESSEL 1841 a = 6,377,397.155 m 1/f = 299.1528128 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 NATIONAL OCEAN SERVICE

  8. ELLIPSOID - GEOID RELATIONSHIP H = Orthometric Height H = h - N h = Ellipsoidal Height N = Geoid Height H TOPOGRAPHIC SURFACE h N Geoid GEOID99 Ellipsoid GRS80 PERPENDICULAR TO ELLIPSOID PERPENDICULAR TO GEOID (PLUMBLINE) DEFLECTION OF THE VERTICAL DEFLEC99

  9. THE GEOID AND TWO ELLIPSOIDS CLARKE 1866 GRS80-WGS84 Earth Mass Center Approximately 236 meters GEOID NATIONAL OCEAN SERVICE

  10. HORIZONTAL DATUMS • BESSEL1841 -------------- 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 1866PUERTO 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

  11. STATUS OF NAD 27 AND NAD 83 STATE PLANE COORDINATE LEGISLATION - AUGUST 1999 • NO SPCS EXISTING NAD 27 ENACTED NAD 83 SPC LEGISLATIONLEGISLATION 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 MetersDelaware(S) Missouri South Dakota • 1 m = 3.280839895 feetFlorida (S) Montana Tennessee (S) • S = U.S. Survey Feet and MetersGeorgia (S) Nevada Texas (S) • 1 m = 3.280833333 feetIdaho (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

  12. GROUND LEVEL COORDINATES • “I WANT STATE PLANE COORDINATES RAISED TO GROUND LEVEL” • GROUND LEVEL COORDINATES ARE NOT STATE PLANE COORDINATES!!!!! NATIONAL OCEAN SERVICE

  13. 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

  14. 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)

  15. 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

  16. GEOID MODELS • OSU 78 • OSU 89B • GEOID 90 • GEOID 93 • GEOID 96 • GEOID 99 • GEOID2000??? NATIONAL OCEAN SERVICE

  17. GEODETIC CONTROL • NETWORK OF MONUMENTED POINTS • PRECISELY MEASURED IN ACCORDANCE • WITH STANDARD PROCEDURES • MEET ACCURACY SPECIFICATIONS • ADJUSTED TO TIE TOGETHER • DOCUMENTED FOR MULTIPLE USE NATIONAL OCEAN SERVICE

  18. 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 - N 260.76 = 225.44 - (-35.31) 260.76 = 260.75 ????

  19. 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.

  20. 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

  21. 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

  22. Autonomous Positioning: Today • C/A Code on L1 • Selective Availability 25-100 m HORIZONTAL = 100 meters VERTICAL = 156 meters 1996 Federal Radionavigation Plan Section A2-1, Part B http://www.navcen.uscg.mil/policy/frp1996

  23. Standalone Positioning: By 2006 • C/A Code on L1 • No Selective Availability 6-11 m

  24. 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

  25. 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

  26. Standalone Positioning: By 2011 • C/A Code on L1 • C/A Code on L2 • New Code on L5 Better resistance to interference 1-3 m

  27. 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) NATIONAL OCEAN SERVICE

  28. INTERNATIONAL TERRESTRIALREFERENCE FRAME • GEOCENTRIC +/- 3 to 4 CM • MODELS FOR PLATE TECTONICS • STATION VELOCITIES • POSITIONAL STANDARD ERRORS • USUALLY BI-ANNUAL PUBLICATION NATIONAL OCEAN SERVICE

  29. CONVENTIONAL TERRESTRIAL SYSTEM(CTS) ZCTS PX,Y,Z Greenwich Meridian Z Earth Mass Center Y X XCTS YCTS Equator NATIONAL OCEAN SERVICE

  30. NAD 83 and ITRF NAD 83 ITRF Earth Mass Center 2.2 m (3-D) dX,dY,dZ GEOID NATIONAL OCEAN SERVICE

  31. ITRF96 (Epoch 1998.0) to NAD83ftp://ftp.ngs.noaa.gov/pub/pcsoft/htdp/ • DX = 0.9910 meters • DY = -1.9072 meters • DZ = -0.5129 meters • rX = 0.02579 seconds • rY = 0.00965 seconds • rZ = 0.01166 seconds • Scale = 0.0 ppm NATIONAL OCEAN SERVICE

  32. ITRF94 (Epoch 1995.0) to NAD83ftp://ftp.ngs.noaa.gov/pub/pcsoft/htdp/ • DX = 0.9769 meters • DY = -1.9392 meters • DZ = -0.5461 meters • rX = 0.02640 seconds • rY = 0.01010 seconds • rZ = 0.01030 seconds • Scale = 0.0 ppm NATIONAL OCEAN SERVICE

  33. NAD 83 NETWORK PROBLEMS • NOT “GPSABLE” • POOR STATION ACCESSIBILITY • IRREGULARLY SPACED • POSITIONAL ACCURACY NATIONAL OCEAN SERVICE

  34. 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

  35. 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

  36. 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

  37. HIGH ACCURACY REFERENCE NETWORKS NATIONAL OCEAN SERVICE

  38. 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

  39. 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

  40. HARN ADJUSTMENT • NAD 83 Data that is NOT Part of NSRS must • be readjusted by contractor/user with original observations NATIONAL OCEAN SERVICE

  41. 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

  42. NAD 83 READJUSTMENT

  43. 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

  44. NAD 83 READJUSTMENT • WILL NOT INCLUDE OLD CONVENTIONAL OBSERVATIONS • TRIANGULATION • TRAVERSE • TRILATERATION • INERTIAL • PHOTOGRAMMETRY NATIONAL OCEAN SERVICE

  45. 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

  46. 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

  47. 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

  48. 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

  49. 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

More Related