Improved Geoid Determination Based on the Shallow-Layer Method: A Case Study Using EGM08 and CRUST2.0 in the Xinjiang and Tibetan Regions

  • Author(s): WenBin Shen and Jiancheng Han
  • DOI: 10.3319/TAO.2012.11.12.01(TibXS)
  • Keywords: New theoretical method, Shallow layer, Regional geoid, GPS leveling benchmarks, CRUST2.0

 

Abstract

In this paper we present the concepts and realization of the shallow-layer Shen geoid determination method, which is quite different from the classical geoid modeling methods (Stokes¡¦ method, Molodenskii¡¦s method, etc.), for determining the global or regional geoids. This method takes full advantage of the precise Earth gravity field model EGM2008, digital topographic model DTM2006.0 and global crust model CRUST2.0 of a shallow layer, a layer from the Earth¡¦s surface to a depth. As a case study this method is applied to the determination of a 5´ × 5´ geoid over the Xinjiang and Tibetan regions, which ranges from latitude 25 to 50°N and longitude 70 to 100°E. The modeled 5´ × 5´ regional geoid is compared with the EGM2008 geoid model in the same study area and validated by 21 GPS/leveling benchmarks (GPSBMs) distributed sparsely in the Xinjiang area. The results show that the regional geoid reaches an accuracy of ~18 cm and agrees with the GPSBMs better than the EGM2008 geoid in the Xinjiang region.

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