Geodesy, engineering survey, topographic mapping.
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "GeodeticReferenceFrame", "name": "Xian 1980", "ellipsoid": { "name": "IAG 1975", "semi_major_axis": 6378140, "inverse_flattening": 298.257 }, "scope": "Geodesy, engineering survey, topographic mapping.", "area": "China - onshore.", "bbox": { "south_latitude": 18.11, "west_longitude": 73.62, "north_latitude": 53.56, "east_longitude": 134.77 }, "id": { "authority": "EPSG", "code": 6610 } }