Potential constellation developments


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POTENTIAL CONSTELLATION DEVELOPMENTS

  • POTENTIAL CONSTELLATION DEVELOPMENTS

  • (10 Years??)

  • GPS MODERNIZATION – BLOCK IIR-M & III

  • GLONASS ENHANCEMENTS

  • EUROPEAN UNION - GALILEO

  • CHINA - COMPASS

  • 100+ Satellites

  • Second and Third Civil Frequency – GPS

  • More Robust Signal Transmissions

  • Real-Time Unaugmented 1 Meter (or better!) Accuracy













ACCURATE -- cm accuracy on a global scale

  • 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 GNSS Service etc.)





A set of constants specifying the coordinate system used for geodetic control, i.e., for calculating coordinates of points on the Earth. Specific geodetic datums are usually given distinctive names. (e.g., North American Datum of 1983, European Datum 1950, National Geodetic Vertical Datum of 1929)

  • A set of constants specifying the coordinate system used for geodetic control, i.e., for calculating coordinates of points on the Earth. Specific geodetic datums are usually given distinctive names. (e.g., North American Datum of 1983, European Datum 1950, National Geodetic Vertical Datum of 1929)



HORIZONTAL

    • HORIZONTAL
    • 2-D (Latitude and Longitude) (e.g. NAD 27, NAD 83 (1986))
    • VERTICAL/GEOPOTENTIAL
    • 1-D (Orthometric Height) (e.g. NGVD 29, NAVD 88, Local Tidal)
    • GEOMETRIC
    • 3-D (Latitude, Longitude and Ellipsoid Height)
    • Fixed and Stable(?) - Coordinates seldom change
    • (e.g. NAD 83 (1993), NAD 83 (2007))
    • also
    • 4-D (Latitude, Longitude, Ellipsoid Height, Velocities) Coordinates change with time
    • (e.g. ITRF00, ITRF05)


8 Constants

  • 8 Constants

  • 3 – specify the location of the origin of the coordinate system.

  • 3– specify the orientation of the coordinate system.

  • 2 – specify the dimensions of the reference ellipsoid



A set of fundamental elevations to which other elevations are referred.

  • A set of fundamental elevations to which other elevations are referred.

  • Datum Types

  • Tidal – Defined by observation of tidal variations over some period of time

  • (MSL, MLLW, MLW, MHW, MHHW etc.)

  • (NOS Center for Operational Oceanographic Products and Services)

  • (CO-OPS)

  • Geodetic – Tided to Local Mean Sea Level at one or more points at some epoch

  • (NAVD 88, IGLD85)































  • STATE PLANE AND UNIVERSAL TRANSVERSE MERCATOR GRID COORDINATES ARE A DIRECT MATHEMATICAL CONVERSION FROM LATITUDE AND LONGITUDE TO A CARTESIAN NORTHING AND EASTING (Y & X) COORDINATE SYSTEM, AND MUST MAINTAIN THE SAME DATUM TAG [e.g. NAD 27 or NAD 83] AS THE LATITUDE AND LONGITUDE)













State plane coordinates are the projection of latitudes and longitudes from the GRS80 ellipsoid

  • State plane coordinates are the projection of latitudes and longitudes from the GRS80 ellipsoid



  • Developed by U.S. Coast and Geodetic Survey from a request in 1933 from the North Carolina Department of Transportation

  • Two basic map projections used:

    • Lambert Conformal Conic – States or parts of states that have a more East-West orientation
    • Transverse Mercator – States or parts of states that have a more North-South orientation
  • Zone boundaries along International, State and county boundaries

  • Zones typically 154 miles wide – this limits the maximum geodetic to grid distance distortion to 1:10,000

  • All coordinate values in U.S. Survey Feet

  • Conversions to/from latitude & longitude calculated using tables

  • (e.g. USC&GS Special Publication. 316 Plane Coordinate Projections Tables – New Jersey)

  • State Plane Coordinates by Automatic Data Processing (USC&GS 62-4)



  • Geometric parameters of original SPC zones left unchanged unless requested by “the State”

  • All states get new false northing and false easting defined in meters.

  • All values in meters – conversions to feet defined by individual state legislation or Federal Register Notice

  • 1 m = 3.2808333333. U.S. Survey Feet

  • 1 m = 3.2808398950 International Feet





  • UTM

  • UTMS (Both NAD 27 & NAD 83)

  • http://www.ngs.noaa.gov/TOOLS/utm.shtml

  • CORPSCON (Both NAD 27 & NAD 83)

  • http://crunch.tec.army.mil/software/corpscon/corpscon.html

  • STATE PLANE COORDINATES

  • GPPCGP (NAD 27 only)

  • SPCS83 (NAD 83 only)

  • http://www.ngs.noaa.gov/TOOLS/spc.shtml

  • CORPSCON (Both NAD 27 & NAD 83)

  • http://crunch.tec.army.mil/software/corpscon/corpscon.html



1. WHAT DATUM ARE THE EXISTING COORDINATES/HEIGHTS ON?

  • 1. WHAT DATUM ARE THE EXISTING COORDINATES/HEIGHTS ON?

  • 2. WHAT DATUM DO I WANT THE NEW COORDINATES/HEIGHTS 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/HEIGHTS?

  • 0.01 Meter

    • 0.1 Meter
    • 1.0 Meter
  • 7. HOW ACCURATE DO I WANT THE NEW COORDINATES/HEIGHTS?



SATISFIES ALL USERS’ REQUIREMENTS

  • SATISFIES ALL USERS’ REQUIREMENTS

  • CAPABLE OF TRANSFORMING LARGE DATASETS

  • NEAR-REAL TIME APPLICATIONS

  • SIMPLE - METHOD SHOULD NOT REQUIRE AN EXPERT OR DECISIONS TO BE MADE

  • ACCURATE



MOLODENSKY

  • 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).



  • VERTCON

  • (NGVD 29 only)

  • NADCON

  • (NAD 27, OLD HAWAIIAN, PUERTO RICO, 3 ALASKA ISLANDS)

  • (HPGN/HARN)



MOLODENSKY

  • 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

  • MOLODENSKY

  • ADJUSTED vs. TRANSFORMED

  • Station: OBSERVATORY (HV7843)

  • LATITUDE LONGITUDE

  • 38-12-06.79868 077-22-22.35067 - PUBLISHED

  • 38-12-06.59040 077-22-22.34223 - MOLODENSKY

  • .20828” .00844”

  • 6.422 m 0.205 m

  • THIS CORRESPONDS TO A POSITIONAL

  • DIFFERENCE OF 6.425 m (21.08 ft)



NADCON

  • NADCON

  • ADJUSTED vs. TRANSFORMED

  • Station: OBSERVATORY (HV7843)

  • LATITUDE LONGITUDE

  • 38-12-06.79868 077-22-22.35067 - PUBLISHED

  • 38-12-06.79920 077-22-22.34823 - NADCON

  • .00052” .00244”

  • 0.016 m 0.059 m

  • THIS CORRESPONDS TO A POSITIONAL

  • DIFFERENCE OF 0.061 m (0.20 ft)






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