Engineering survey, topographic mapping.
Replaced by Nord Sahara 1959 / Voirol Unifie Sud (code 30792). The appropriate usage of CRSs using the Voirol 1875 and 1879 datums is lost in antiquity. They differ by about 9 metres. Oil industry references to one could in reality be to either.
Algeria - 35.6 grads to 38.5 grads North (32°N to 34°39'N).
Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: m.
534438.57 302832.64
-33639.34 154785.9
1103449.63 468731.29
-2.95 31.99
9.09 34.66
Definition: OGC Well Known Text
PROJCS["Voirol 1879 / Sud Algerie (ancienne)", GEOGCS["Voirol 1879", DATUM["Voirol_1879", SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627, AUTHORITY["EPSG","7011"]], AUTHORITY["EPSG","6671"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4671"]], PROJECTION["Lambert_Conformal_Conic_1SP"], PARAMETER["latitude_of_origin",33.3], PARAMETER["central_meridian",2.7], PARAMETER["scale_factor",0.999625769], PARAMETER["false_easting",500000], PARAMETER["false_northing",300000], UNIT["metre",1, AUTHORITY["EPSG","9001"]], AXIS["Easting",EAST], AXIS["Northing",NORTH], AUTHORITY["EPSG","30494"]]
Definition: OGC Well Known Text 2 (2019)
PROJCRS["Voirol 1879 / Sud Algerie (ancienne)", BASEGEOGCRS["Voirol 1879", DATUM["Voirol 1879", ELLIPSOID["Clarke 1880 (IGN)",6378249.2,293.466021293627, LENGTHUNIT["metre",1]]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",4671]], CONVERSION["Sud Algerie (ancienne)", METHOD["Lambert Conic Conformal (1SP)", ID["EPSG",9801]], PARAMETER["Latitude of natural origin",37, ANGLEUNIT["grad",0.0157079632679489], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",3, ANGLEUNIT["grad",0.0157079632679489], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",0.999625769, SCALEUNIT["unity",1], ID["EPSG",8805]], PARAMETER["False easting",500000, LENGTHUNIT["metre",1], ID["EPSG",8806]], PARAMETER["False northing",300000, LENGTHUNIT["metre",1], ID["EPSG",8807]]], CS[Cartesian,2], AXIS["easting (X)",east, ORDER[1], LENGTHUNIT["metre",1]], AXIS["northing (Y)",north, ORDER[2], LENGTHUNIT["metre",1]], USAGE[ SCOPE["Engineering survey, topographic mapping."], AREA["Algeria - 35.6 grads to 38.5 grads North (32°N to 34°39'N)."], BBOX[31.99,-2.95,34.66,9.09]], ID["EPSG",30494]]
Definition: ESRI Well Known Text
PROJCS["Voirol_1879_Sud_Algerie_Ancienne", GEOGCS["GCS_Voirol_1879", DATUM["D_Voirol_1879", SPHEROID["Clarke_1880_IGN",6378249.2,293.466021293627]], PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]], PROJECTION["Lambert_Conformal_Conic"], PARAMETER["False_Easting",500000.0], PARAMETER["False_Northing",300000.0], PARAMETER["Central_Meridian",2.7], PARAMETER["Standard_Parallel_1",33.3], PARAMETER["Scale_Factor",0.999625769], PARAMETER["Latitude_Of_Origin",33.3], UNIT["Meter",1.0]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "ProjectedCRS", "name": "Voirol 1879 / Sud Algerie (ancienne)", "base_crs": { "name": "Voirol 1879", "datum": { "type": "GeodeticReferenceFrame", "name": "Voirol 1879", "ellipsoid": { "name": "Clarke 1880 (IGN)", "semi_major_axis": 6378249.2, "semi_minor_axis": 6356515 } }, "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": 4671 } }, "conversion": { "name": "Sud Algerie (ancienne)", "method": { "name": "Lambert Conic Conformal (1SP)", "id": { "authority": "EPSG", "code": 9801 } }, "parameters": [ { "name": "Latitude of natural origin", "value": 37, "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 }, "id": { "authority": "EPSG", "code": 8801 } }, { "name": "Longitude of natural origin", "value": 3, "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 }, "id": { "authority": "EPSG", "code": 8802 } }, { "name": "Scale factor at natural origin", "value": 0.999625769, "unit": "unity", "id": { "authority": "EPSG", "code": 8805 } }, { "name": "False easting", "value": 500000, "unit": "metre", "id": { "authority": "EPSG", "code": 8806 } }, { "name": "False northing", "value": 300000, "unit": "metre", "id": { "authority": "EPSG", "code": 8807 } } ] }, "coordinate_system": { "subtype": "Cartesian", "axis": [ { "name": "Easting", "abbreviation": "X", "direction": "east", "unit": "metre" }, { "name": "Northing", "abbreviation": "Y", "direction": "north", "unit": "metre" } ] }, "scope": "Engineering survey, topographic mapping.", "area": "Algeria - 35.6 grads to 38.5 grads North (32°N to 34°39'N).", "bbox": { "south_latitude": 31.99, "west_longitude": -2.95, "north_latitude": 34.66, "east_longitude": 9.09 }, "id": { "authority": "EPSG", "code": 30494 } }
Definition: GeoServer
30494=PROJCS["Voirol 1879 / Sud Algerie (ancienne)",GEOGCS["Voirol 1879",DATUM["Voirol_1879",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627,AUTHORITY["EPSG","7011"]],AUTHORITY["EPSG","6671"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4671"]],PROJECTION["Lambert_Conformal_Conic_1SP"],PARAMETER["latitude_of_origin",33.3],PARAMETER["central_meridian",2.7],PARAMETER["scale_factor",0.999625769],PARAMETER["false_easting",500000],PARAMETER["false_northing",300000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","30494"]]
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=lcc +lat_1=33.3 +lat_0=33.3 +lon_0=2.7 +k_0=0.999625769 +x_0=500000 +y_0=300000 +ellps=clrk80ign +units=m +no_defs +type=crs"> <Layer srs="+proj=lcc +lat_1=33.3 +lat_0=33.3 +lon_0=2.7 +k_0=0.999625769 +x_0=500000 +y_0=300000 +ellps=clrk80ign +units=m +no_defs +type=crs"> </Layer> </Map>
Definition: SQL (PostGIS)
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 30494, 'EPSG', 30494, '+proj=lcc +lat_1=33.3 +lat_0=33.3 +lon_0=2.7 +k_0=0.999625769 +x_0=500000 +y_0=300000 +ellps=clrk80ign +units=m +no_defs +type=crs', 'PROJCS["Voirol 1879 / Sud Algerie (ancienne)",GEOGCS["Voirol 1879",DATUM["Voirol_1879",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627,AUTHORITY["EPSG","7011"]],AUTHORITY["EPSG","6671"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4671"]],PROJECTION["Lambert_Conformal_Conic_1SP"],PARAMETER["latitude_of_origin",33.3],PARAMETER["central_meridian",2.7],PARAMETER["scale_factor",0.999625769],PARAMETER["false_easting",500000],PARAMETER["false_northing",300000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","30494"]]');