Geodetic CRS: WGS 84
Datum: World Geodetic System 1984 ensemble
Data source: EPSG
Information source: US National Geospatial-Intelligence Agency (NGA), https://earth-info.nga.mil/ and Pavlis, N. K. et al, Journal of Geophysical Research: Solid Earth, volume 117 Issue B4, 2012-04-19, https://doi.org/10.1029/2011JB008916
Revision date: 2025-07-10
Scope: Derivation of gravity-related heights from GNSS observations.
Remarks: Replaces WGS 84 to EGM96 height (1) (CT code 10084). Grid spacing is 2.5 arc-minutes. For a file with smaller (1 arc-minute) grid spacing (in principle more exactly representing the spherical harmonics) see CT code 3859. For reversible alternative see CT code 9704. An executable using spherical harmonics is available from the NGA site.
Method: Geographic3D to GravityRelatedHeight (EGM2008)
Area of use: World.
Description: (0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["WGS 84 to EGM2008 height (1)", VERSION["NGA-World 2.5min"], 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)"], MEMBER["World Geodetic System 1984 (G2296)"], 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["EGM2008 height", VDATUM["EGM2008 geoid"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["metre",1]], ID["EPSG",3855]]], METHOD["Geographic3D to GravityRelatedHeight (EGM2008)", ID["EPSG",1025]], PARAMETERFILE["Geoid (height correction) model file","Und_min2.5x2.5_egm2008_isw=82_WGS84_TideFree"], OPERATIONACCURACY[0.113], USAGE[ SCOPE["Derivation of gravity-related heights from GNSS observations."], AREA["World."], BBOX[-90,-180,90,180]], ID["EPSG",3858], REMARK["Replaces WGS 84 to EGM96 height (1) (CT code 10084). Grid spacing is 2.5 arc-minutes. For a file with smaller (1 arc-minute) grid spacing (in principle more exactly representing the spherical harmonics) see CT code 3859. For reversible alternative see CT code 9704. An executable using spherical harmonics is available from the NGA site."]]
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:3858","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=us_nga_egm08_25.tif +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 EGM2008 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 } }, { "name": "World Geodetic System 1984 (G2296)", "id": { "authority": "EPSG", "code": 1383 } } ], "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": "EGM2008 height", "datum": { "type": "VerticalReferenceFrame", "name": "EGM2008 geoid" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 3855 } }, "method": { "name": "Geographic3D to GravityRelatedHeight (EGM2008)", "id": { "authority": "EPSG", "code": 1025 } }, "parameters": [ { "name": "Geoid (height correction) model file", "value": "Und_min2.5x2.5_egm2008_isw=82_WGS84_TideFree", "id": { "authority": "EPSG", "code": 8666 } } ], "accuracy": "0.113", "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": 3858 }, "remarks": "Replaces WGS 84 to EGM96 height (1) (CT code 10084). Grid spacing is 2.5 arc-minutes. For a file with smaller (1 arc-minute) grid spacing (in principle more exactly representing the spherical harmonics) see CT code 3859. For reversible alternative see CT code 9704. An executable using spherical harmonics is available from the NGA site." }
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=us_nga_egm08_25.tif" "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=us_nga_egm08_25.tif +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=us_nga_egm08_25.tif +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 ( 3858, 'EPSG', 3858, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=us_nga_egm08_25.tif +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');