Geocentric translations (geog2D domain)
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.
St. Helena Government, Environment and Natural Resources Directorate (ENRD).
2020-03-14
metre
EPSG
St. Helena Government, Environment and Natural Resources Directorate (ENRD).
2016-11-25
Topographic mapping.
Replaced by SHMG2015 (CRS code 7887) from 2015.
St Helena, Ascension and Tristan da Cunha - St Helena Island - onshore.
Cartesian 2D CS. Axes: easting, northing (E,N). Orientations: east, north. UoM: m.
299126.75 2000712.2
285201.69 1987981.8
313051.39 2013437.88
-5.85 -16.08
-5.59 -15.85
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)
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",-323.65, ID["EPSG",8605]], PARAMETER["Y-axis translation",551.39, ID["EPSG",8606]], PARAMETER["Z-axis translation",-491.22, ID["EPSG",8607]], PARAMETER["X-axis rotation",0, ID["EPSG",8608]], PARAMETER["Y-axis rotation",0, ID["EPSG",8609]], PARAMETER["Z-axis rotation",0, ID["EPSG",8610]], PARAMETER["Scale difference",1, 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: 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": -323.65, "unit": "metre", "id": { "authority": "EPSG", "code": 8605 } }, { "name": "Y-axis translation", "value": 551.39, "unit": "metre", "id": { "authority": "EPSG", "code": 8606 } }, { "name": "Z-axis translation", "value": -491.22, "unit": "metre", "id": { "authority": "EPSG", "code": 8607 } }, { "name": "X-axis rotation", "value": 0, "unit": { "type": "AngularUnit", "name": "arc-second", "conversion_factor": 4.84813681109536e-06 }, "id": { "authority": "EPSG", "code": 8608 } }, { "name": "Y-axis rotation", "value": 0, "unit": { "type": "AngularUnit", "name": "arc-second", "conversion_factor": 4.84813681109536e-06 }, "id": { "authority": "EPSG", "code": 8609 } }, { "name": "Z-axis rotation", "value": 0, "unit": { "type": "AngularUnit", "name": "arc-second", "conversion_factor": 4.84813681109536e-06 }, "id": { "authority": "EPSG", "code": 8610 } }, { "name": "Scale difference", "value": 0, "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[-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: 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"]]');