EPSG:4901 ATF (Paris)
Geographic system in latitude and longitude, in use: France - mainland onshore. Datum, ellipsoid and transformation to WGS 84 below.
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:4901 |
|---|---|
| Name | ATF (Paris) |
| Type | Geographic system |
| Area of use | France - mainland onshore |
| Bounds | W -4,87° · S 42,33° · E 8,23° · N 51,14° |
| Countries | France |
| Datum | Ancienne Triangulation Francaise (Paris) |
| Ellipsoid | Plessis 1817 a = 6376523 m · 1/f = 308.64 |
| Prime meridian | Paris RGS 2.3372083333333333 degree |
| Unit | grad (Lat north, Lon east) |
| Transformation to WGS 84 | No simple transformation published (ellipsoid alone) |
| Scope | Geodesy. |
proj4 definition
+proj=longlat +a=6376523 +rf=308.64 +pm=2.33720833333333 +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:4901.
WKT (ESRI format, the .prj content)
GEOGCS["GCS_ATF_Paris",DATUM["D_ATF",SPHEROID["Plessis_1817",6376523.0,308.64]],PRIMEM["Paris_RGS",2.33720833333333],UNIT["Grad",0.0157079632679489]]Other systems — France
- EPSG:2154RGF93 v1 / Lambert-93
- EPSG:3942RGF93 v1 / CC42
- EPSG:3943RGF93 v1 / CC43
- EPSG:3944RGF93 v1 / CC44
- EPSG:3945RGF93 v1 / CC45
- EPSG:3946RGF93 v1 / CC46
- EPSG:3947RGF93 v1 / CC47
- EPSG:3948RGF93 v1 / CC48
- EPSG:3949RGF93 v1 / CC49
- EPSG:3950RGF93 v1 / CC50
- EPSG:4171RGF93 v1
- EPSG:4275NTF
- EPSG:4807NTF (Paris)
- EPSG:5627ED50 / TM 6 NE
- EPSG:7084RGF93 v1 (lon-lat)
- EPSG:9547LTF2004(G)
- EPSG:9549LTF2004(C)
- EPSG:9777RGF93 v2
Source: EPSG registry v11.022 (IOGP), through the PROJ database. Always check a code on epsg.org before contractual work.