USGG2003 is a gravimetric geoid that served as the basis for GEOID03 within the conterminous United States only.
USGG2003 is very similar to G99SSS differing only in the use of GSFC00.1 instead of KMS98 for the offshore gravity field. The result of changing the altimeter-implied FAGA data was to significantly improve the gravimetric geoid primarily along the East Coast and especially in Florida (a reduction from 40 to 30 cm in misfit).
This 25% improvement was determined by comparison with
GPSBM2003
point data. USGG2003 uses the same
data format and spacing as G99SSS and can easily
swapped in software applications.
