EPSG
Conseil National de l'Information Geographique groupe de travail "Reseaux de Nivellement" recommendations v5.1 April 1994.
1996-09-12
Geodesy, topographic mapping.
The CNIG states that NGF is a general term applying to all vertical network readjustments of France and recommends more specific terminology. See codes 5118-5120.
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "VerticalReferenceFrame", "name": "Nivellement general de la France", "scope": "Geodesy, topographic mapping.", "area": "France - mainland onshore.", "bbox": { "south_latitude": 42.33, "west_longitude": -4.87, "north_latitude": 51.14, "east_longitude": 8.23 }, "id": { "authority": "EPSG", "code": 5107 } }