Abstract：The method of establishing the mean freeair gravity anomaly reference field with rare gravity data has been studied based on the Airy and Heiskanen isostatic theory. The numerical model of the mean freeair gravity anomalies has been established using the regional highresolution topographic data; then for the problem that the systematic errors existed in the computational area, a few of gravimetric points have been chosen as constraint points in order to eliminate errors. Finally, the comparisons have been made among the gravity field model of EGM2008 and interpolation using separate points. As a result, the method could get better precision than two other methods as well as could reduce workloads in gravity measurement in the fields, the method is suitable for establishing the mean freeair gravity anomalies in difficult conditions.
