EPSG:29702 Tananarive (Paris) / Laborde Grid approximation
Projected system (Hotine Oblique Mercator (variant B)) in use: Madagascar - onshore. The full definition below, and conversion in one click.
EPSG publishes no simple transformation to WGS 84 for this datum: conversion works on the ellipsoid alone and can be off by tens of metres.
| Code | EPSG:29702 |
|---|---|
| Name | Tananarive (Paris) / Laborde Grid approximation |
| Type | Projected system — Hotine Oblique Mercator (variant B) |
| Area of use | Madagascar - onshore |
| Bounds | W 43,18° · S -25,64° · E 50,56° · N -11,89° |
| Countries | Madagascar |
| Datum | Tananarive 1925 (Paris) |
| Ellipsoid | International 1924 a = 6378388 m · 1/f = 297 |
| Prime meridian | Paris 2.5969213 grad |
| Base geographic system | EPSG:4810 — Tananarive (Paris) |
| Unit | metre (X north, Y east) |
| Transformation to WGS 84 | No simple transformation published (ellipsoid alone) |
| Scope | Topographic mapping (medium scale). |
Projection parameters
| Parameter | Value | Unit |
|---|---|---|
| Latitude of projection centre | -21 | grad |
| Longitude of projection centre | 49 | grad |
| Azimuth at projection centre | 21 | grad |
| Angle from Rectified to Skew Grid | 21 | grad |
| Scale factor at projection centre | 0.9995 | unity |
| Easting at projection centre | 400000 | metre |
| Northing at projection centre | 800000 | metre |
proj4 definition
+proj=omerc +lat_0=-18.9 +lonc=44.1 +alpha=18.9 +gamma=18.9 +k=0.9995 +x_0=400000 +y_0=800000 +ellps=intl +pm=paris +units=m +no_defsPaste it into QGIS, proj4js, PostGIS (spatial_ref_sys) or GDAL. +towgs84 carries the EPSG transformation to WGS 84; the official code stays EPSG:29702.
WKT (ESRI format, the .prj content)
PROJCS["Tananarive_Paris_Laborde_Grid_approximation",GEOGCS["GCS_Tananarive_1925_Paris",DATUM["Tananarive_1925_(Paris)",SPHEROID["International_1924",6378388.0,297.0]],PRIMEM["Paris",2.33722917],UNIT["Grad",0.0157079632679489]],PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],PARAMETER["False_Easting",400000.0],PARAMETER["False_Northing",800000.0],PARAMETER["Scale_Factor",0.9995],PARAMETER["Azimuth",21.0],PARAMETER["Longitude_Of_Center",49.0],PARAMETER["Latitude_Of_Center",-21.0],UNIT["Meter",1.0]]Other systems — Madagascar
Source: EPSG registry v11.022 (IOGP), through the PROJ database. Always check a code on epsg.org before contractual work.