World Geodetic System 1984 ensemble
EPSG
US National Geospatial-Intelligence Agency (NGA); https://earth-info.nga.mil/GandG/wgs84/gravitymod/
2022-03-02
Derivation of gravity-related heights from GNSS observations.
File may also be found named as "EGM84.GRD". An executable using spherical harmonics is also available. Replaced by WGS 84 to EGM96 height (1) (CT code 10084).
Geographic3D to GravityRelatedHeight (EGM)
(0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["WGS 84 to EGM84 height (1)", VERSION["NGA-World"], SOURCECRS[ GEOGCRS["WGS 84", ENSEMBLE["World Geodetic System 1984 ensemble", MEMBER["World Geodetic System 1984 (Transit)"], MEMBER["World Geodetic System 1984 (G730)"], MEMBER["World Geodetic System 1984 (G873)"], MEMBER["World Geodetic System 1984 (G1150)"], MEMBER["World Geodetic System 1984 (G1674)"], MEMBER["World Geodetic System 1984 (G1762)"], MEMBER["World Geodetic System 1984 (G2139)"], ELLIPSOID["WGS 84",6378137,298.257223563, LENGTHUNIT["metre",1]], ENSEMBLEACCURACY[2.0]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], CS[ellipsoidal,3], AXIS["geodetic latitude (Lat)",north, ORDER[1], ANGLEUNIT["degree",0.0174532925199433]], AXIS["geodetic longitude (Lon)",east, ORDER[2], ANGLEUNIT["degree",0.0174532925199433]], AXIS["ellipsoidal height (h)",up, ORDER[3], LENGTHUNIT["metre",1]], ID["EPSG",4979]]], TARGETCRS[ VERTCRS["EGM84 height", VDATUM["EGM84 geoid"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["metre",1]], ID["EPSG",5798]]], METHOD["Geographic3D to GravityRelatedHeight (EGM)", ID["EPSG",9661]], PARAMETERFILE["Geoid (height correction) model file","DIRACC.DAT"], OPERATIONACCURACY[1.0], USAGE[ SCOPE["Derivation of gravity-related heights from GNSS observations."], AREA["World."], BBOX[-90,-180,90,180]], ID["EPSG",15781], REMARK["File may also be found named as ""EGM84.GRD"". An executable using spherical harmonics is also available. Replaced by WGS 84 to EGM96 height (1) (CT code 10084)."]]
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:15781","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=DIRACC.DAT +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "Transformation", "name": "WGS 84 to EGM84 height (1)", "source_crs": { "type": "GeographicCRS", "name": "WGS 84", "datum_ensemble": { "name": "World Geodetic System 1984 ensemble", "members": [ { "name": "World Geodetic System 1984 (Transit)", "id": { "authority": "EPSG", "code": 1166 } }, { "name": "World Geodetic System 1984 (G730)", "id": { "authority": "EPSG", "code": 1152 } }, { "name": "World Geodetic System 1984 (G873)", "id": { "authority": "EPSG", "code": 1153 } }, { "name": "World Geodetic System 1984 (G1150)", "id": { "authority": "EPSG", "code": 1154 } }, { "name": "World Geodetic System 1984 (G1674)", "id": { "authority": "EPSG", "code": 1155 } }, { "name": "World Geodetic System 1984 (G1762)", "id": { "authority": "EPSG", "code": 1156 } }, { "name": "World Geodetic System 1984 (G2139)", "id": { "authority": "EPSG", "code": 1309 } } ], "ellipsoid": { "name": "WGS 84", "semi_major_axis": 6378137, "inverse_flattening": 298.257223563 }, "accuracy": "2.0", "id": { "authority": "EPSG", "code": 6326 } }, "coordinate_system": { "subtype": "ellipsoidal", "axis": [ { "name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": "degree" }, { "name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": "degree" }, { "name": "Ellipsoidal height", "abbreviation": "h", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 4979 } }, "target_crs": { "type": "VerticalCRS", "name": "EGM84 height", "datum": { "type": "VerticalReferenceFrame", "name": "EGM84 geoid" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 5798 } }, "method": { "name": "Geographic3D to GravityRelatedHeight (EGM)", "id": { "authority": "EPSG", "code": 9661 } }, "parameters": [ { "name": "Geoid (height correction) model file", "value": "DIRACC.DAT", "id": { "authority": "EPSG", "code": 8666 } } ], "accuracy": "1.0", "scope": "Derivation of gravity-related heights from GNSS observations.", "area": "World.", "bbox": { "south_latitude": -90, "west_longitude": -180, "north_latitude": 90, "east_longitude": 180 }, "id": { "authority": "EPSG", "code": 15781 }, "remarks": "File may also be found named as \"EGM84.GRD\". An executable using spherical harmonics is also available. Replaced by WGS 84 to EGM96 height (1) (CT code 10084)." }
Definition: MapServer - MAPfile
PROJECTION "proj=pipeline" "step" "proj=axisswap" "order=2,1" "step" "proj=unitconvert" "xy_in=deg" "xy_out=rad" "step" "inv" "proj=vgridshift" "grids=DIRACC.DAT" "multiplier=1" "step" "proj=unitconvert" "xy_in=rad" "xy_out=deg" "step" "proj=axisswap" "order=2,1" END
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=DIRACC.DAT +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> <Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=DIRACC.DAT +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> </Layer> </Map>
Definition: SQL (PostGIS)
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 15781, 'EPSG', 15781, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=DIRACC.DAT +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');