EPSG:30491 — Voirol 1875 / Nord Algerie (ancienne)

Projected · Algeria - north of 34°39'N

Export Formats

OGC WKT

PROJCS[
    "Voirol 1875 / Nord Algerie (ancienne)",
    GEOGCS[
        "Voirol 1875",
        DATUM[
            "Voirol_1875",
            SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627],
            TOWGS84[-73,-247,227,0,0,0,0]
        ],
        PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4304"]
    ],
    PROJECTION["Lambert_Conformal_Conic_1SP"],
    PARAMETER["latitude_of_origin",36],
    PARAMETER["central_meridian",2.7],
    PARAMETER["scale_factor",0.999625544],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",300000],
    UNIT["metre",1,AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","30491"]
]

WKT2

PROJCRS[
    "Voirol 1875 / Nord Algerie (ancienne)",
    BASEGEOGCRS[
        "Voirol 1875",
        DATUM[
            "Voirol 1875",
            ELLIPSOID[
                "Clarke 1880 (IGN)",
                6378249.2,
                293.466021293627,
                LENGTHUNIT["metre",1,ID["EPSG",9001]],
                ID["EPSG",7011]
            ],
            ID["EPSG",6304]
        ],
        ID["EPSG",4304]
    ],
    CONVERSION[
        "Nord Algerie (ancienne)",
        METHOD["Lambert Conic Conformal (1SP)",ID["EPSG",9801]],
        PARAMETER[
            "Latitude of natural origin",
            40,
            ANGLEUNIT["grad",0.015707963267949,ID["EPSG",9105]],
            ID["EPSG",8801]
        ],
        PARAMETER[
            "Longitude of natural origin",
            3,
            ANGLEUNIT["grad",0.015707963267949,ID["EPSG",9105]],
            ID["EPSG",8802]
        ],
        PARAMETER[
            "Scale factor at natural origin",
            0.999625544,
            SCALEUNIT["unity",1,ID["EPSG",9201]],
            ID["EPSG",8805]
        ],
        PARAMETER[
            "False easting",
            500000,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",8806]
        ],
        PARAMETER[
            "False northing",
            300000,
            LENGTHUNIT["metre",1,ID["EPSG",9001]],
            ID["EPSG",8807]
        ],
        ID["EPSG",18011]
    ],
    CS[Cartesian,2,ID["EPSG",4499]],
    AXIS["Easting (X)",east],
    AXIS["Northing (Y)",north],
    LENGTHUNIT["metre",1,ID["EPSG",9001]],
    ID["EPSG",30491]
]

PROJ.4

+proj=lcc +lat_1=36 +lat_0=36 +lon_0=2.7 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +towgs84=-73,-247,227,0,0,0,0 +units=m +no_defs +type=crs

Proj4js

How to add a projection to Proj4js? →

proj4.defs("EPSG:30491", "+proj=lcc +lat_1=36 +lat_0=36 +lon_0=2.7 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +towgs84=-73,-247,227,0,0,0,0 +units=m +no_defs +type=crs");

JSON

{
  "type": "CoordinateReferenceSystem",
  "code": 30491,
  "name": "Voirol 1875 / Nord Algerie (ancienne)",
  "kind": "projected",
  "area": "Algeria - north of 34°39'N",
  "unit": "metre",
  "bbox": [
    34.64,
    -2.22,
    37.14,
    8.64
  ],
  "proj4": "+proj=lcc +lat_1=36 +lat_0=36 +lon_0=2.7 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +towgs84=-73,-247,227,0,0,0,0 +units=m +no_defs +type=crs"
}

PostGIS

How to add a projection to PostGIS? →

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (30491, 'EPSG', 30491, '+proj=lcc +lat_1=36 +lat_0=36 +lon_0=2.7 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +towgs84=-73,-247,227,0,0,0,0 +units=m +no_defs +type=crs', 'PROJCS["Voirol 1875 / Nord Algerie (ancienne)",GEOGCS["Voirol 1875",DATUM["Voirol_1875",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627],TOWGS84[-73,-247,227,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4304"]],PROJECTION["Lambert_Conformal_Conic_1SP"],PARAMETER["latitude_of_origin",36],PARAMETER["central_meridian",2.7],PARAMETER["scale_factor",0.999625544],PARAMETER["false_easting",500000],PARAMETER["false_northing",300000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","30491"]]');

MapServer

How to add a projection to MapServer? →

PROJECTION
  "+proj=lcc"
  "+lat_1=36"
  "+lat_0=36"
  "+lon_0=2.7"
  "+k_0=0.999625544"
  "+x_0=500000"
  "+y_0=300000"
  "+ellps=clrk80ign"
  "+towgs84=-73,-247,227,0,0,0,0"
  "+units=m"
  "+no_defs"
  "+type=crs"
END

GeoServer

How to add a projection to GeoServer? →

30491=PROJCS["Voirol 1875 / Nord Algerie (ancienne)",GEOGCS["Voirol 1875",DATUM["Voirol_1875",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627],TOWGS84[-73,-247,227,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4304"]],PROJECTION["Lambert_Conformal_Conic_1SP"],PARAMETER["latitude_of_origin",36],PARAMETER["central_meridian",2.7],PARAMETER["scale_factor",0.999625544],PARAMETER["false_easting",500000],PARAMETER["false_northing",300000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","30491"]]

Related Coordinate Systems

Available Transformations (2)

Transformations inherited from base CRS: EPSG:4304 (Voirol 1875)

Transformation	Source → Target	Accuracy (m)
Voirol 1875 (Paris) to Voirol 1875 (1)	4811 → 4304	0
Voirol 1875 to WGS 84 (1)	4304 → 4326	999

Other CRS using Voirol 1875

Frequently Asked Questions

How do I add EPSG:30491 to GeoServer?

Add the following definition to your GeoServer configuration:

30491=PROJCS["Voirol 1875 / Nord Algerie (ancienne)",GEOGCS["Voirol 1875",DATUM["Voirol_1875",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627],TOWGS84[-73,-247,227,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4304"]],PROJECTION["Lambert_Conformal_Conic_1SP"],PARAMETER["latitude_of_origin",36],PARAMETER["central_meridian",2.7],PARAMETER["scale_factor",0.999625544],PARAMETER["false_easting",500000],PARAMETER["false_northing",300000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","30491"]]

Read the full GeoServer guide →

How do I add EPSG:30491 to PostGIS?

Add the following definition to your PostGIS configuration:

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (30491, 'EPSG', 30491, '+proj=lcc +lat_1=36 +lat_0=36 +lon_0=2.7 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +towgs84=-73,-247,227,0,0,0,0 +units=m +no_defs +type=crs', 'PROJCS["Voirol 1875 / Nord Algerie (ancienne)",GEOGCS["Voirol 1875",DATUM["Voirol_1875",SPHEROID["Clarke 1880 (IGN)",6378249.2,293.466021293627],TOWGS84[-73,-247,227,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4304"]],PROJECTION["Lambert_Conformal_Conic_1SP"],PARAMETER["latitude_of_origin",36],PARAMETER["central_meridian",2.7],PARAMETER["scale_factor",0.999625544],PARAMETER["false_easting",500000],PARAMETER["false_northing",300000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","30491"]]');

Read the full PostGIS guide →

How do I add EPSG:30491 to MapServer?

Add the following definition to your MapServer configuration:

PROJECTION
  "+proj=lcc"
  "+lat_1=36"
  "+lat_0=36"
  "+lon_0=2.7"
  "+k_0=0.999625544"
  "+x_0=500000"
  "+y_0=300000"
  "+ellps=clrk80ign"
  "+towgs84=-73,-247,227,0,0,0,0"
  "+units=m"
  "+no_defs"
  "+type=crs"
END

Read the full MapServer guide →

How do I use EPSG:30491 with Proj4js?

Add the following definition to your Proj4js configuration:

proj4.defs("EPSG:30491", "+proj=lcc +lat_1=36 +lat_0=36 +lon_0=2.7 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +towgs84=-73,-247,227,0,0,0,0 +units=m +no_defs +type=crs");

Read the full Proj4js guide →

Type

Projected

Unit

metre

Geodetic CRS

Voirol 1875

Datum

Voirol 1875

Ellipsoid

Clarke 1880 (IGN)

Prime Meridian

Greenwich

Area of Use

Algeria - north of 34°39'N

Algeria - onshore north of 38.5 grads North (34°39'N).

Coordinate System

Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: m.

Center Coordinates

546273.49 288018.17

Projected Bounds

442638.09 49377.281027585.86 160632.94

WGS84 Bounds

37.14 -2.228.64 34.64

Data Source

EPSG

Revision Date

1995-06-02

Scope

Engineering survey, topographic mapping.

Remarks

Replaced by Nord Sahara 1959 / Voirol Unifie Nord (code 30791). 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.

EPSG

30491