EPSG:7877

Astro DOS 71 / SHLG71

Transform Get position on a map

Available transformations
to EPSG:7886
EPSG:7886 - SHGD2015

Selected transformation

Method: Position Vector transformation (geog2D domain)

Remarks: Derived at 19 stations, RMS = 6cm. Note: Because of the large rotations about the Y- and Z-axes this transformation is not reversible. For the reverse transformation use SHGD2015 to Astro DOS 71 (2) (code 9226).

Information source: St. Helena Government, Environment and Natural Resources Directorate (ENRD).

Revision date: 2019-10-14

Attributes

Unit: metre

Geodetic CRS: Astro DOS 71

Datum: Astro DOS 71

Ellipsoid: International 1924

Prime meridian: Greenwich

Data source: EPSG

Information source: St. Helena Government, Environment and Natural Resources Directorate (ENRD).

Revision date: 2016-11-25

Scope: Topographic mapping.

Remarks: Replaced by SHMG2015 (CRS code 7887) from 2015.

Area of use: St Helena, Ascension and Tristan da Cunha - St Helena Island - onshore.

Coordinate system: Cartesian 2D CS. Axes: easting, northing (E,N). Orientations: east, north. UoM: m.

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SimpleMap

Center coordinates
299126.78 2000712.1

Projected bounds:
285201.19 1987981.15
313051.43 2013438.03

WGS84 bounds:
-5.85 -16.08
-5.59 -15.85

St Helena, Ascension and Tristan da Cunha - St Helena Island - onshore.
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Definition: OGC Well Known Text

PROJCS["Astro DOS 71 / SHLG71",
    GEOGCS["Astro DOS 71",
        DATUM["Astro_DOS_71",
            SPHEROID["International 1924",6378388,297],
            TOWGS84[-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4710"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",-15.9666666666667],
    PARAMETER["central_meridian",-5.71666666666667],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",300000],
    PARAMETER["false_northing",2000000],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","7877"]]

Definition: OGC Well Known Text 2 (2019)

BOUNDCRS[
    SOURCECRS[
        PROJCRS["Astro DOS 71 / SHLG71",
            BASEGEOGCRS["Astro DOS 71",
                DATUM["Astro DOS 71",
                    ELLIPSOID["International 1924",6378388,297,
                        LENGTHUNIT["metre",1]]],
                PRIMEM["Greenwich",0,
                    ANGLEUNIT["degree",0.0174532925199433]],
                ID["EPSG",4710]],
            CONVERSION["St. Helena Local Grid 1971",
                METHOD["Transverse Mercator",
                    ID["EPSG",9807]],
                PARAMETER["Latitude of natural origin",-15.9666666666667,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8801]],
                PARAMETER["Longitude of natural origin",-5.71666666666667,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8802]],
                PARAMETER["Scale factor at natural origin",1,
                    SCALEUNIT["unity",1],
                    ID["EPSG",8805]],
                PARAMETER["False easting",300000,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8806]],
                PARAMETER["False northing",2000000,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8807]]],
            CS[Cartesian,2],
                AXIS["(E)",east,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["(N)",north,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
            USAGE[
                SCOPE["Topographic mapping."],
                AREA["St Helena, Ascension and Tristan da Cunha - St Helena Island - onshore."],
                BBOX[-16.08,-5.85,-15.85,-5.59]],
            ID["EPSG",7877]]],
    TARGETCRS[
        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]],
            USAGE[
                SCOPE["Horizontal component of 3D system."],
                AREA["World."],
                BBOX[-90,-180,90,180]],
            ID["EPSG",4326]]],
    ABRIDGEDTRANSFORMATION["Transformation from unknown to WGS84",
        METHOD["Position Vector transformation (geog2D domain)",
            ID["EPSG",9606]],
        PARAMETER["X-axis translation",-112.854,
            ID["EPSG",8605]],
        PARAMETER["Y-axis translation",12.27,
            ID["EPSG",8606]],
        PARAMETER["Z-axis translation",-18.913,
            ID["EPSG",8607]],
        PARAMETER["X-axis rotation",2.1692,
            ID["EPSG",8608]],
        PARAMETER["Y-axis rotation",16.8896,
            ID["EPSG",8609]],
        PARAMETER["Z-axis rotation",17.1961,
            ID["EPSG",8610]],
        PARAMETER["Scale difference",0.99998045483,
            ID["EPSG",8611]]]]

Definition: ESRI Well Known Text

PROJCS["Astro_DOS_71_4_SHLG71",
    GEOGCS["GCS_DOS_71_4",
        DATUM["D_DOS_71_4",
            SPHEROID["International_1924",6378388.0,297.0]],
        PRIMEM["Greenwich",0.0],
        UNIT["Degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["False_Easting",300000.0],
    PARAMETER["False_Northing",2000000.0],
    PARAMETER["Central_Meridian",-5.71666666666667],
    PARAMETER["Scale_Factor",1.0],
    PARAMETER["Latitude_Of_Origin",-15.9666666666667],
    UNIT["Meter",1.0]]

Definition: PROJ.4

+proj=tmerc +lat_0=-15.9666666666667 +lon_0=-5.71666666666667 +k=1 +x_0=300000 +y_0=2000000 +ellps=intl +towgs84=-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517 +units=m +no_defs +type=crs

Definition: JavaScript (Proj4js) 

proj4.defs("EPSG:7877","+proj=tmerc +lat_0=-15.9666666666667 +lon_0=-5.71666666666667 +k=1 +x_0=300000 +y_0=2000000 +ellps=intl +towgs84=-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517 +units=m +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "BoundCRS",
    "source_crs": {
        "type": "ProjectedCRS",
        "name": "Astro DOS 71 / SHLG71",
        "base_crs": {
            "name": "Astro DOS 71",
            "datum": {
                "type": "GeodeticReferenceFrame",
                "name": "Astro DOS 71",
                "ellipsoid": {
                    "name": "International 1924",
                    "semi_major_axis": 6378388,
                    "inverse_flattening": 297
                }
            },
            "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": 4710
            }
        },
        "conversion": {
            "name": "St. Helena Local Grid 1971",
            "method": {
                "name": "Transverse Mercator",
                "id": {
                    "authority": "EPSG",
                    "code": 9807
                }
            },
            "parameters": [
                {
                    "name": "Latitude of natural origin",
                    "value": -15.9666666666667,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8801
                    }
                },
                {
                    "name": "Longitude of natural origin",
                    "value": -5.71666666666667,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8802
                    }
                },
                {
                    "name": "Scale factor at natural origin",
                    "value": 1,
                    "unit": "unity",
                    "id": {
                        "authority": "EPSG",
                        "code": 8805
                    }
                },
                {
                    "name": "False easting",
                    "value": 300000,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8806
                    }
                },
                {
                    "name": "False northing",
                    "value": 2000000,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8807
                    }
                }
            ]
        },
        "coordinate_system": {
            "subtype": "Cartesian",
            "axis": [
                {
                    "name": "Easting",
                    "abbreviation": "E",
                    "direction": "east",
                    "unit": "metre"
                },
                {
                    "name": "Northing",
                    "abbreviation": "N",
                    "direction": "north",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 7877
        }
    },
    "target_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
        }
    },
    "transformation": {
        "name": "Transformation from unknown to WGS84",
        "method": {
            "name": "Position Vector transformation (geog2D domain)",
            "id": {
                "authority": "EPSG",
                "code": 9606
            }
        },
        "parameters": [
            {
                "name": "X-axis translation",
                "value": -112.854,
                "unit": "metre",
                "id": {
                    "authority": "EPSG",
                    "code": 8605
                }
            },
            {
                "name": "Y-axis translation",
                "value": 12.27,
                "unit": "metre",
                "id": {
                    "authority": "EPSG",
                    "code": 8606
                }
            },
            {
                "name": "Z-axis translation",
                "value": -18.913,
                "unit": "metre",
                "id": {
                    "authority": "EPSG",
                    "code": 8607
                }
            },
            {
                "name": "X-axis rotation",
                "value": 2.1692,
                "unit": {
                    "type": "AngularUnit",
                    "name": "arc-second",
                    "conversion_factor": 4.84813681109536e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8608
                }
            },
            {
                "name": "Y-axis rotation",
                "value": 16.8896,
                "unit": {
                    "type": "AngularUnit",
                    "name": "arc-second",
                    "conversion_factor": 4.84813681109536e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8609
                }
            },
            {
                "name": "Z-axis rotation",
                "value": 17.1961,
                "unit": {
                    "type": "AngularUnit",
                    "name": "arc-second",
                    "conversion_factor": 4.84813681109536e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8610
                }
            },
            {
                "name": "Scale difference",
                "value": -19.54517,
                "unit": {
                    "type": "ScaleUnit",
                    "name": "parts per million",
                    "conversion_factor": 1e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8611
                }
            }
        ]
    }
}

Definition: GeoServer

7877=PROJCS["Astro DOS 71 / SHLG71",GEOGCS["Astro DOS 71",DATUM["Astro_DOS_71",SPHEROID["International 1924",6378388,297],TOWGS84[-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4710"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",-15.9666666666667],PARAMETER["central_meridian",-5.71666666666667],PARAMETER["scale_factor",1],PARAMETER["false_easting",300000],PARAMETER["false_northing",2000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","7877"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=tmerc"
	"lat_0=-15.9666666666667"
	"lon_0=-5.71666666666667"
	"k=1"
	"x_0=300000"
	"y_0=2000000"
	"ellps=intl"
	"towgs84=-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517"
	"units=m"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=tmerc +lat_0=-15.9666666666667 +lon_0=-5.71666666666667 +k=1 +x_0=300000 +y_0=2000000 +ellps=intl +towgs84=-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517 +units=m +no_defs +type=crs">
	<Layer srs="+proj=tmerc +lat_0=-15.9666666666667 +lon_0=-5.71666666666667 +k=1 +x_0=300000 +y_0=2000000 +ellps=intl +towgs84=-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517 +units=m +no_defs +type=crs">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 7877, 'EPSG', 7877, '+proj=tmerc +lat_0=-15.9666666666667 +lon_0=-5.71666666666667 +k=1 +x_0=300000 +y_0=2000000 +ellps=intl +towgs84=-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517 +units=m +no_defs +type=crs', 'PROJCS["Astro DOS 71 / SHLG71",GEOGCS["Astro DOS 71",DATUM["Astro_DOS_71",SPHEROID["International 1924",6378388,297],TOWGS84[-112.854,12.27,-18.913,2.1692,16.8896,17.1961,-19.54517]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4710"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",-15.9666666666667],PARAMETER["central_meridian",-5.71666666666667],PARAMETER["scale_factor",1],PARAMETER["false_easting",300000],PARAMETER["false_northing",2000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","7877"]]');