EPSG
International Earth Rotation Service (IERS) Technical Note No. 6, April 1991. Also IGN Paris http://lareg.ensg.ign.fr/ITRF
2020-08-31
Geodesy.
Realization of the IERS Terrestrial Reference System (ITRS) from April 1991. Replaces ITRF88 (code 6647). Replaced by ITRF90 (code 6649).
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "DynamicGeodeticReferenceFrame", "name": "International Terrestrial Reference Frame 1989", "frame_reference_epoch": 1988, "ellipsoid": { "name": "GRS 1980", "semi_major_axis": 6378137, "inverse_flattening": 298.257222101 }, "scope": "Geodesy.", "area": "World.", "bbox": { "south_latitude": -90, "west_longitude": -180, "north_latitude": 90, "east_longitude": 180 }, "id": { "authority": "EPSG", "code": 6648 } }