EPSG:9704

WGS 84 to WGS 84 + EGM2008 height (1)

Attributes

Geodetic CRS: WGS 84

Datum: World Geodetic System 1984 ensemble

Data source: EPSG

Information source: US National Geospatial-Intelligence Agency (NGA). "The development and evaluation of the Earth Gravitational Model 2008 (EGM2008)", Journal of Geophysical Research: Solid Earth, volume 117 Issue B4, 2012-04-19.

Revision date: 2023-01-17

Scope: Reversible geoid model transformation.

Remarks: Reversible alternative to WGS 84 to EGM2008 height (1) (code 3858).

Method: Geog3D to Geog2D+GravityRelatedHeight (EGM2008)

Area of use: World.

Description: (0,)

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Definition: OGC Well Known Text 2 (2019)

COORDINATEOPERATION["WGS 84 to WGS 84 + 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)"],
                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[
        COMPOUNDCRS["WGS 84 + EGM2008 height",
            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,2],
                    AXIS["geodetic latitude (Lat)",north,
                        ORDER[1],
                        ANGLEUNIT["degree",0.0174532925199433]],
                    AXIS["geodetic longitude (Lon)",east,
                        ORDER[2],
                        ANGLEUNIT["degree",0.0174532925199433]]],
            VERTCRS["EGM2008 height",
                VDATUM["EGM2008 geoid"],
                CS[vertical,1],
                    AXIS["gravity-related height (H)",up,
                        LENGTHUNIT["metre",1]]],
            ID["EPSG",9518]]],
    METHOD["Geog3D to Geog2D+GravityRelatedHeight (EGM2008)",
        ID["EPSG",1092]],
    PARAMETERFILE["Geoid (height correction) model file","Und_min2.5x2.5_egm2008_isw=82_WGS84_TideFree.gz"],
    INTERPOLATIONCRS[
        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,2],
                AXIS["geodetic latitude (Lat)",north,
                    ORDER[1],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["geodetic longitude (Lon)",east,
                    ORDER[2],
                    ANGLEUNIT["degree",0.0174532925199433]]]],
    OPERATIONACCURACY[1.0],
    USAGE[
        SCOPE["Reversible geoid model transformation."],
        AREA["World."],
        BBOX[-90,-180,90,180]],
    ID["EPSG",9704],
    REMARK["Reversible alternative to WGS 84 to EGM2008 height (1) (code 3858)."]]

Definition: PROJ.4

+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: JavaScript (Proj4js)

proj4.defs("EPSG:9704","+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 WGS 84 + 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
                    }
                }
            ],
            "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": "CompoundCRS",
        "name": "WGS 84 + EGM2008 height",
        "components": [
            {
                "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"
                        }
                    ]
                }
            },
            {
                "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": 9518
        }
    },
    "interpolation_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"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 4326
        }
    },
    "method": {
        "name": "Geog3D to Geog2D+GravityRelatedHeight (EGM2008)",
        "id": {
            "authority": "EPSG",
            "code": 1092
        }
    },
    "parameters": [
        {
            "name": "Geoid (height correction) model file",
            "value": "Und_min2.5x2.5_egm2008_isw=82_WGS84_TideFree.gz",
            "id": {
                "authority": "EPSG",
                "code": 8666
            }
        }
    ],
    "accuracy": "1.0",
    "scope": "Reversible geoid model transformation.",
    "area": "World.",
    "bbox": {
        "south_latitude": -90,
        "west_longitude": -180,
        "north_latitude": 90,
        "east_longitude": 180
    },
    "id": {
        "authority": "EPSG",
        "code": 9704
    },
    "remarks": "Reversible alternative to WGS 84 to EGM2008 height (1) (code 3858)."
}

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 ( 9704, 'EPSG', 9704, '+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');