Algeria Geodetic Coordinate Converter

About the Coordinate Systems

Geographic Coordinates (Lat/Lon WGS84): Standard GPS system using decimal degrees on the WGS84 ellipsoid.

UTM WGS84: Universal Transverse Mercator on the WGS84 ellipsoid — the international standard for GPS-based cartography. Zones 30, 31 and 32 cover Algeria.

UTM Nord Sahara 1959 (Clarke 1880): Algerian geodetic datum based on the Clarke 1880 (RGS) ellipsoid, historically used for topographic mapping in Algeria. A 7-parameter Helmert transformation is applied to shift between WGS84 and this datum (ΔX=−209m, ΔY=87m, ΔZ=−210m — IGN values for Nord Sahara 1959).

Lambert Voirol Ancien (Algérie): Conical conformal projection used during the French colonial period. Zone I (Nord Algérie) has a parallel of origin of 36°00′N and a false northing of 300,000 m. Zone II (Sud Algérie) has a parallel of 33°18′N and a false northing of 200,000 m. Both use a central meridian of 2°42′E (Paris meridian offset) and are based on the Clarke 1880 ellipsoid.

Important Notes

• The Helmert shift parameters for Nord Sahara 1959 are those published by the IGN (Institut Géographique National). Accuracy is approximately ±5 m.
• Lambert Voirol Ancien uses the Paris meridian as origin; the central meridian in Greenwich degrees is 2.596898° E (= 2°42′E = 0° Paris).
• For high-precision surveying, always verify against official Algerian geodetic control points.