1. Mean earth's ellipsoid based on Doppler satellite observations;Anderle,1978
2. NWL-8D geodetic parameters based on Doppler satellite observations;Anderle,1967
3. The GRIM 2 earth gravity field model;Balmino,1976
4. Brace, K., , Preliminary ocean area geoid from Geos-3 satellite radar altimetry, Def. Mapp. Agency Aerosp. Center, St. Louis, Mo., 1977,
5. 1° × 1° mean free-air gravity anomalies;Defense Mapping Agency Aerospace Center,1973