Compensating Method of the Height Anomalies for Ultra-High Earth’s Gravity Field Model

EIGEN-6C4 and EGM2008 ultra-high Earth’s gravity field models on their expanded order and degree are limited and exist certain omission errors. The RTM residual height anomalies is obtained from SRTM data and DTM2006.0 data via a prism integral forward-modelling method. The testing results show that (1) before fitting via RTM height anomalies the standard deviation of model height anomalies for EIGEN-6C4 and EGM2008 can be improved by 5.7 mm, the improvement rate respectively is 10 and 7%. (2) After fitting via RTM height anomalies their standard deviations can respectively be improved by 1.0 and 3.3 cm, the improvement rate respectively is 2 and 6%. (3) The RTM height anomalies change along with the increasing of the integral radius, and their values is tending towards stability, are converged to 2 cm, the height anomalies values of EIGEN-6C4 and EGM2008 models change respectively to be in order of cm in scope of 110 km and in scope of 105 km. (4) The RTM technique is an effective method of compensating the accuracy of ultra-high Earth’s gravity field model to the benefit of raising the quasigeoid accuracy.