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Abstract:
Global geoid plays key role in world height system. Here we report the 5’ times 5’ global geoid model 2022 (GGM2022) established based on the shallow layer method (Shen method). We chose an inner surface E below the EGM2008 global geoid by 15 m, and the layer bounded by E and the Earth’s geographical surface is called shallow layer. We formulated the 3D shallow mass layer model using a refined 5’ times 5’ crust density model CRUST_re based on the density model CRUST2.0/ CRUST1.0 with considering the influences of ice sheets and land-ocean crossing regions. After it was determined an extended gravity field model EGM2008e defined in the whole region outside E, based on the geodetic equation W(P)=W0 (W0 the geopotential constant on the geoid and W(P) the geopotential at arbitrary point P), the 5’ times 5’ global geoid model GGM2022 was established. Comparisons show that GGM2022 fits the available GPS/leveling data better than the EGM2008 global geoid in the USA, Europe, and the western part of China. This study is supported by the National Natural Science Foundation of China (Nos. 42030105, 41721003), and Fundamental Research Funds for the Central Universities of China.
