مقايسه مدل هاي ژئوپتانسيلي جديد در منطقه فارس ساحلي در توليد تابعك اندازه بردار شتاب ثقل

Comparison of Four Recent Geopotential Models based on Synthesis of Modulus of Gravity Acceleration Vectorat a Test Area in Southern Coast of Iran

Recent progresses in Satellite, airborne and surface gravimetry as well as satellite altimetry techniques had led to production of high-resolution geopotential models. Those models, being computed based on high-quality gravity data, are well representing medium and long wave spectrums of the external gravity field of the earth and as such have become indispensable part of modern algorithms for local gravity field modeling. Due to the variety of existing geopotential models, it is necessary to investigate their quality at different geographical regions by their comparison with the observed gravity functional in order to select the one which best suits to the geographical region of interest. In this paper, four geopotential models, namely, EGM96, PGM2000A, GGM01S, and GPM98CR are compared for their quality in synthesis of the modulus of gravity acceleration vector at 6350 gravity observation points in a test area in southern coast of Iran. The numerical results show that GPM98CR geopotential model has best performance, among the tested geopotential models, at the test area. Besides, combination of aforementioned geopotential models is studied and it was found that combination of the two geopotential model PGM2000A (from degree and order 91 to 360) and EGM96 (from degree and order 0 to 90) can be considered as the best combination for the synthesis of the modulus of gravity acceleration vector at the test area