spatial reference - magip
TRANSCRIPT
Slide 1METADATA?? Horizontal Datum??
Plane Coordinate Zone ??
Units of Measure ??
METADATA - Data About Data DATUMS
NAD 27, NAD 83 (1986), NAD 83 (199x), NAD 83 (NSRS 2007), NGVD 29, NAVD 88
UNITS
Meters, U.S. Survey Feet, International Feet, Varas, Toise, Chains, Rods, Poles, Links, Perches
ACCURACY
A, B, 1st, 2nd, 3rd, 3 cm, 1 m, Scaled
National Spatial Reference System (NSRS)
Consistent National Coordinate System
NSRS
ACRONYMS US
Geodetic Datums
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)
Characterized by: A set of physical monuments, related by survey
measurements and resulting coordinates (horizontal and/or vertical) for those monuments
Geodetic Datums
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 (1992), NAD 83 (1999), NAD 83 (2007)]
also
The Ellipsoid Mathematical Model of the Earth
a = Semi major axis b = Semi minor axis f = a-b = Flattening
a
b
a
N
S
Horizontal Coordinates and Ellipsoid Heights are related to the Ellipsoid
a= 637813.000007 meters b= 6356752.31414 meters f= 1/((a-b)/a) = 298.2572220972 a = 6,378,137.00000 m
b =
Squash the sphere to fit at the poles
An ellipsoid of revolution is the figure which would be obtained by rotating an ellipse about its shorter axis. An ellipsoid of revolution describing the figure of the Earth is called a reference ellipsoid.
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.
GEODETIC REFERENCE SYSTEM 1980 - (GRS 80) a = 6,378,137 m 1/f = 298.2572221
WORLD GEODETIC SYSTEM 1984 - (WGS 84) a = 6,378,137 m 1/f = 298.257223563
for NAD 83 Datum
for WGS 84 Datum
North American Datum Of 1983
NAD 83 (1986) – 2D & passive ~ 1 m national integrity (1986 – 1990)
NAD 83 (199x) – 3D & passive ~ 10 cm national integrity (1990 – 1997)
NAD 83 (CORS96) – 4D & active ~ 2 cm national integrity (1994 – Present)
NAD 83 (2007) – 3D & passive ~ 2 cm relative to CORS (2007 – Present)
Federal Register Notice: Vol. 54, No. 113, June 14, 1989, pg. 25318 “Affirmation of Datum for Surveying and Mapping Activities”
This the difference in meters on the ground between the same latitude/longitude coordinate in the two datums. If you project latitude/longitude data into another coordinate system such as UTM or state plane, the difference between the coordinates of a particular location on the ground in the two datums is usually greater than what is shown here, because the projection software shows the difference in the datums PLUS the effect of using different ellipsoids in the projection equations.
Difference Between NAD 27 and NAD 83 (meters)
Courtesy of Gerry Daumiller ([email protected]), Montana State Library
Where the transformation grids had no values, no transformation was done.
Difference Between NAD 83 and NAD 83 HPGN/HARN
Courtesy of Gerry Daumiller ([email protected]), Montana State Library
HARN High Accuracy Reference Network
HPGN High Precision Geodetic Network
Courtesy of Gerry Daumiller ([email protected]), Montana State Library
Datum / Latitude (N) Longitude (W) Ellipsoid Difference Adjustment Height (meters)
NAD27 47 39 56.79000 112 15 47.46800 n/a
NAD83(1986) 47 39 56.61495 112 15 50.53760 n/a N +5.408 E +64.054
NAD83(1992) 47 39 56.60839 112 15 50.55223 1395.328 N +0.203 E +0.305
NAD83(1999) 47 39 56.60945 112 15 50.55341 1395.258 N -0.033 E +0.025 U +0.070
NAD83(NSRS) 47 39 56.60950 112 15 50.55274 1395.232 N -0.002 (Epoch 2002.00) E -0.014
U +0.026
WGS84(G1150)47 39 56.63180 112 15 50.60376 1394.683 N -0.689 (ITRF 2000) E +1.065
U +0.549
ARE NAD 83 & WGS 84 THE SAME?
Federal Register Notice: Vol. 60, No. 157, August 15, 1995, pg. 42146 “Use of NAD 83/WGS 84 Datum Tag on Mapping Products”
IT DEPENDS
World Geodetic System 1984
DATUM = WGS 84(G730) 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) 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://earth-info.nima.mil/GandG/sathtml/IONReport8-20-02.pdf
H O
W M
A N
Y W
????
ARE NAD 83 & WGS 84 THE SAME? NAD 83 to ITRF00 dX = 0.9956 m dY = - 1.9013 m dZ = - 0.5215 m S = 0.62 x 10-9
rX = 25.915 mas rY = 9.426 mas rZ = 11.599 mas
MY SOFTWARE SAYS I’M WORKING IN WGS 84
Project tied to WGS 84 control points obtained from the Defense Department -- Good Luck!
You’re really working in the same reference frame as your control points -- NAD 83?
Unless you are doing autonomous positioning (point positioning +/- 6-10 meters) you’re probably NOT in WGS 84
Image credit: University of Texas Center for Space Research and NASA
GRACE Gravity Model 01 - Released July 2003
Orthometric Heights are related to the Geoid
Ellipsoid - Geoid Relationship
H = h – [N]
h = Ellipsoidal Height [NAD 83 (2007) or (CORS96)] N = Geoid Height (GEOID 09)
H h
Ellipsoid GRS80
Geoid GEOID09
Vertical Datums 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 – Tied to Local Mean Sea Level at one or more points at some epoch
(NGVD 29, NAVD 88, IGLD 85)
Vertical Datums Of The United States Current Reference Systems
North American Vertical Datum of 1988 (NAVD 88)
American Samoa Vertical Datum of 2002 (ASVD 02)
Northern Marians Vertical Datum of 2003 (NMVD 03)
Guam Vertical Datum of 2004 (GUVD 04)
Federal Register Notice: Vol. 58, No. 120, June 24, 1993, pg. 34245 “Affirmation of Vertical Datum for Surveying and Mapping Activities”
Federal Register Notices for American Samoa, Guam and Northern Marians: Vol. 74, No. 13, January 22, 2009, pgs 3990 - 3991
NGS Datum Transformation Models
NADCON
3 Alaska Islands)
(NAD 83 HPGN/HARN)
Federal Register Notice: Vol. 55, No. 155, August 10, 1990, pg. 32681 “Notice to Adopt Standard Method for Mathematical Horizontal Datum Transformation”
Federal Register Notice: Vol. 72, No. 132, July 11, 2007, pg. 37732 “Notice to Adopt a Standard Model for Mathematical Vertical Datum Transformations”
Datum Transformations - Considerations 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
www.ngs.noaa.gov
Slide Number 12
Slide Number 15
Slide Number 16
Slide Number 17
Slide Number 18
Slide Number 20
Slide Number 21
MY SOFTWARE SAYS I’M WORKING IN WGS 84
Slide Number 24
Ellipsoid - Geoid Relationship
NGS Datum Transformation Models
Plane Coordinate Zone ??
Units of Measure ??
METADATA - Data About Data DATUMS
NAD 27, NAD 83 (1986), NAD 83 (199x), NAD 83 (NSRS 2007), NGVD 29, NAVD 88
UNITS
Meters, U.S. Survey Feet, International Feet, Varas, Toise, Chains, Rods, Poles, Links, Perches
ACCURACY
A, B, 1st, 2nd, 3rd, 3 cm, 1 m, Scaled
National Spatial Reference System (NSRS)
Consistent National Coordinate System
NSRS
ACRONYMS US
Geodetic Datums
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)
Characterized by: A set of physical monuments, related by survey
measurements and resulting coordinates (horizontal and/or vertical) for those monuments
Geodetic Datums
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 (1992), NAD 83 (1999), NAD 83 (2007)]
also
The Ellipsoid Mathematical Model of the Earth
a = Semi major axis b = Semi minor axis f = a-b = Flattening
a
b
a
N
S
Horizontal Coordinates and Ellipsoid Heights are related to the Ellipsoid
a= 637813.000007 meters b= 6356752.31414 meters f= 1/((a-b)/a) = 298.2572220972 a = 6,378,137.00000 m
b =
Squash the sphere to fit at the poles
An ellipsoid of revolution is the figure which would be obtained by rotating an ellipse about its shorter axis. An ellipsoid of revolution describing the figure of the Earth is called a reference ellipsoid.
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.
GEODETIC REFERENCE SYSTEM 1980 - (GRS 80) a = 6,378,137 m 1/f = 298.2572221
WORLD GEODETIC SYSTEM 1984 - (WGS 84) a = 6,378,137 m 1/f = 298.257223563
for NAD 83 Datum
for WGS 84 Datum
North American Datum Of 1983
NAD 83 (1986) – 2D & passive ~ 1 m national integrity (1986 – 1990)
NAD 83 (199x) – 3D & passive ~ 10 cm national integrity (1990 – 1997)
NAD 83 (CORS96) – 4D & active ~ 2 cm national integrity (1994 – Present)
NAD 83 (2007) – 3D & passive ~ 2 cm relative to CORS (2007 – Present)
Federal Register Notice: Vol. 54, No. 113, June 14, 1989, pg. 25318 “Affirmation of Datum for Surveying and Mapping Activities”
This the difference in meters on the ground between the same latitude/longitude coordinate in the two datums. If you project latitude/longitude data into another coordinate system such as UTM or state plane, the difference between the coordinates of a particular location on the ground in the two datums is usually greater than what is shown here, because the projection software shows the difference in the datums PLUS the effect of using different ellipsoids in the projection equations.
Difference Between NAD 27 and NAD 83 (meters)
Courtesy of Gerry Daumiller ([email protected]), Montana State Library
Where the transformation grids had no values, no transformation was done.
Difference Between NAD 83 and NAD 83 HPGN/HARN
Courtesy of Gerry Daumiller ([email protected]), Montana State Library
HARN High Accuracy Reference Network
HPGN High Precision Geodetic Network
Courtesy of Gerry Daumiller ([email protected]), Montana State Library
Datum / Latitude (N) Longitude (W) Ellipsoid Difference Adjustment Height (meters)
NAD27 47 39 56.79000 112 15 47.46800 n/a
NAD83(1986) 47 39 56.61495 112 15 50.53760 n/a N +5.408 E +64.054
NAD83(1992) 47 39 56.60839 112 15 50.55223 1395.328 N +0.203 E +0.305
NAD83(1999) 47 39 56.60945 112 15 50.55341 1395.258 N -0.033 E +0.025 U +0.070
NAD83(NSRS) 47 39 56.60950 112 15 50.55274 1395.232 N -0.002 (Epoch 2002.00) E -0.014
U +0.026
WGS84(G1150)47 39 56.63180 112 15 50.60376 1394.683 N -0.689 (ITRF 2000) E +1.065
U +0.549
ARE NAD 83 & WGS 84 THE SAME?
Federal Register Notice: Vol. 60, No. 157, August 15, 1995, pg. 42146 “Use of NAD 83/WGS 84 Datum Tag on Mapping Products”
IT DEPENDS
World Geodetic System 1984
DATUM = WGS 84(G730) 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) 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://earth-info.nima.mil/GandG/sathtml/IONReport8-20-02.pdf
H O
W M
A N
Y W
????
ARE NAD 83 & WGS 84 THE SAME? NAD 83 to ITRF00 dX = 0.9956 m dY = - 1.9013 m dZ = - 0.5215 m S = 0.62 x 10-9
rX = 25.915 mas rY = 9.426 mas rZ = 11.599 mas
MY SOFTWARE SAYS I’M WORKING IN WGS 84
Project tied to WGS 84 control points obtained from the Defense Department -- Good Luck!
You’re really working in the same reference frame as your control points -- NAD 83?
Unless you are doing autonomous positioning (point positioning +/- 6-10 meters) you’re probably NOT in WGS 84
Image credit: University of Texas Center for Space Research and NASA
GRACE Gravity Model 01 - Released July 2003
Orthometric Heights are related to the Geoid
Ellipsoid - Geoid Relationship
H = h – [N]
h = Ellipsoidal Height [NAD 83 (2007) or (CORS96)] N = Geoid Height (GEOID 09)
H h
Ellipsoid GRS80
Geoid GEOID09
Vertical Datums 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 – Tied to Local Mean Sea Level at one or more points at some epoch
(NGVD 29, NAVD 88, IGLD 85)
Vertical Datums Of The United States Current Reference Systems
North American Vertical Datum of 1988 (NAVD 88)
American Samoa Vertical Datum of 2002 (ASVD 02)
Northern Marians Vertical Datum of 2003 (NMVD 03)
Guam Vertical Datum of 2004 (GUVD 04)
Federal Register Notice: Vol. 58, No. 120, June 24, 1993, pg. 34245 “Affirmation of Vertical Datum for Surveying and Mapping Activities”
Federal Register Notices for American Samoa, Guam and Northern Marians: Vol. 74, No. 13, January 22, 2009, pgs 3990 - 3991
NGS Datum Transformation Models
NADCON
3 Alaska Islands)
(NAD 83 HPGN/HARN)
Federal Register Notice: Vol. 55, No. 155, August 10, 1990, pg. 32681 “Notice to Adopt Standard Method for Mathematical Horizontal Datum Transformation”
Federal Register Notice: Vol. 72, No. 132, July 11, 2007, pg. 37732 “Notice to Adopt a Standard Model for Mathematical Vertical Datum Transformations”
Datum Transformations - Considerations 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
www.ngs.noaa.gov
Slide Number 12
Slide Number 15
Slide Number 16
Slide Number 17
Slide Number 18
Slide Number 20
Slide Number 21
MY SOFTWARE SAYS I’M WORKING IN WGS 84
Slide Number 24
Ellipsoid - Geoid Relationship
NGS Datum Transformation Models