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EPSG Library · North Africa

EPSG:22391 — Carthage / Nord Tunisie

Source: EPSG Dataset via PROJ 9.5.1 · Updated

Summary

EPSG:22391 (Carthage / Nord Tunisie) is a projected coordinate reference system on the Carthage datum using the Lambert Conic Conformal (1SP) method, with coordinates in metres. Area of use: Tunisia - onshore north of 38.

  • Type: projected
  • Datum: Carthage
  • Units: metre
  • Axes: X, Y

Definition

EPSG:22391 as published in the EPSG Dataset (PROJ 9.5.1).
PropertyValue
EPSG codeEPSG:22391
NameCarthage / Nord Tunisie
TypeProjected CRS
DatumCarthage
EllipsoidClarke 1880 (IGN) (a = 6,378,249.200 m, 1/f = 293.466021)
Prime meridianGreenwich
Projection methodLambert Conic Conformal (1SP)
AxesEasting (X, east, metre); Northing (Y, north, metre)
ScopeEngineering survey, topographic mapping.
Bounding box8.18° to 11.37° longitude, 34.65° to 37.4° latitude

Area of use

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

Projection parameters

Lambert Conic Conformal (1SP) parameters.
ParameterValueUnit
Latitude of natural origin40grad
Longitude of natural origin11grad
Scale factor at natural origin0.999625544unity
False easting500,000metre
False northing300,000metre

Example coordinates

A WGS 84 point at longitude 9.775°, latitude 36.025° (inside the area of use) has these coordinates in EPSG:22391:

Computed with PROJ using the EPSG default operation: unavailable until proj_trans is called.
AxisValueUnit
X488,687.131m
Y302,612.594m

At this point the projection scale factor is 0.99962564 and the grid convergence is -0.073473°.

Open this conversion in the coordinate converter

Transformations to WGS 84

Candidate operations from the EPSG Dataset, best first as ranked by PROJ.
OperationAccuracyArea of use
axis order change (2D) + Carthage to WGS 84 (1) + axis order change (2D)14 mTunisia - onshore and offshore.
axis order change (2D) + Carthage to WGS 84 (2) + axis order change (2D)1 mTunisia - offshore.

Transformations change the datum, so each has an accuracy and an area of use. Choose the most accurate one that covers your data and record its name. See datum transformations.

Definitions and downloads

PROJ string

+proj=lcc +lat_1=36 +lat_0=36 +lon_0=9.9 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +units=m +no_defs +type=crs

A PROJ string cannot carry every EPSG detail (axis order, datum ensemble, transformations). Prefer WKT2 or the EPSG code itself.

Proj4js definition used by the converter

+proj=lcc +lat_1=36 +lat_0=36 +lon_0=9.9 +k_0=0.999625544 +x_0=500000 +y_0=300000 +ellps=clrk80ign +units=m +towgs84=-260.1,5.5,432.2 +no_defs

Datum shift from Carthage to WGS 84 (2) (EPSG accuracy 1 m), the best single Helmert operation for this area of use. Where PROJ prefers a grid-based or multi-step operation (see the table above), results can differ by up to that operation's accuracy.

WKT2:2019
PROJCRS["Carthage / Nord Tunisie", BASEGEOGCRS["Carthage", DATUM["Carthage", ELLIPSOID["Clarke 1880 (IGN)",6378249.2,293.466021293627, LENGTHUNIT["metre",1]]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",4223]], CONVERSION["Nord Tunisie", METHOD["Lambert Conic Conformal (1SP)", ID["EPSG",9801]], PARAMETER["Latitude of natural origin",40, ANGLEUNIT["grad",0.0157079632679489], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",11, ANGLEUNIT["grad",0.0157079632679489], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",0.999625544, 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["Tunisia - onshore north of 38.5 grads North (34°39'N)."], BBOX[34.65,8.18,37.4,11.37]], ID["EPSG",22391]]

Downloads

FAQ

What is EPSG:22391?

EPSG:22391 (Carthage / Nord Tunisie) is a projected coordinate reference system on the Carthage datum using the Lambert Conic Conformal (1SP) method, with coordinates in metres. Area of use: Tunisia - onshore north of 38.

Where can EPSG:22391 be used?

Its area of use is: Tunisia - onshore north of 38.5 grads North (34°39'N).

Is EPSG:22391 in metres or degrees?

EPSG:22391 is projected, so coordinates are easting and northing in metres, not degrees.

How do I convert EPSG:22391 to latitude and longitude?

Transform from EPSG:22391 to EPSG:4326 (WGS 84). In GeoCAD Bridge open the coordinate converter with EPSG:22391 preselected, enter easting and northing, and choose WGS 84 as the target.

How accurate is the transformation from EPSG:22391 to WGS 84?

The most accurate EPSG transformation listed here is “axis order change (2D) + Carthage to WGS 84 (2) + axis order change (2D)”, with a stated accuracy of 1 m for Tunisia - offshore.. Always check the area of use before applying it.

Coordinate systems

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Tools

References

  1. IOGP. EPSG Geodetic Parameter Dataset, epsg.org/crs_22391.
  2. PROJ 9.5.1 / pyproj 3.7.2, used to compute every value on this page.

Cite this page

GeoCAD Bridge. “EPSG:22391 — Carthage / Nord Tunisie.” GeoCAD Bridge EPSG Library, updated 2026-10-05. https://www.geocadbridge.com/epsg/22391/