EPSG:7877

Astro DOS 71 / SHLG71

Transform Get position on a map

Available transformations
to EPSG:4326
EPSG:4326 - WGS 84

Selected transformation

Method: Geocentric translations (geog2D domain)

Remarks: Parameter values from Astro DOS 71 to SHGD2015 (1) (tfm code 7893). Assumes SHGD2015 and WGS 84 can be considered the same to within the accuracy of the transformation.

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

Revision date: 2020-03-14

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
299126.75 2000712.2

Projected bounds:
285201.69 1987981.8
313051.39 2013437.88

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[-323.65,551.39,-491.22,0,0,0,0]],
        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)

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]]

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=-323.65,551.39,-491.22,0,0,0,0 +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=-323.65,551.39,-491.22,0,0,0,0 +units=m +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "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"
            }
        ]
    },
    "scope": "Topographic mapping.",
    "area": "St Helena, Ascension and Tristan da Cunha - St Helena Island - onshore.",
    "bbox": {
        "south_latitude": -16.08,
        "west_longitude": -5.85,
        "north_latitude": -15.85,
        "east_longitude": -5.59
    },
    "id": {
        "authority": "EPSG",
        "code": 7877
    }
}

Definition: GeoServer

7877=PROJCS["Astro DOS 71 / SHLG71",GEOGCS["Astro DOS 71",DATUM["Astro_DOS_71",SPHEROID["International 1924",6378388,297],TOWGS84[-323.65,551.39,-491.22,0,0,0,0]],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=-323.65,551.39,-491.22,0,0,0,0"
	"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=-323.65,551.39,-491.22,0,0,0,0 +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=-323.65,551.39,-491.22,0,0,0,0 +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=-323.65,551.39,-491.22,0,0,0,0 +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[-323.65,551.39,-491.22,0,0,0,0]],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"]]');