Combined Adjustment of GPS Observations and Geoid Heights in Japan

A technique of combined adjustment of GPS and terrestrial observations is developed by using a local geoid model JGEOID93 (Kuroishi 1995 and 1996) as stochastic observations to reconcile the two different coordinate systems between GPS and terrestrial surveys. Numerical results of the combined adjustment demonstrate that the accuracy of orthometric heights estimated from GPS observations will be as small as a few centimeters.