超高阶地球位模型的计算与分析

Analysis and Computation of Ultra High Degree Geopotential Model

全球重力场模型是当今物理大地测量学最为活跃的研究领域之一。本文基于目前国内外最新的重力场模型理论研究成果 ,提出了利用中国地区细部数据和全球卫星测高 2′× 2′网格重力异常扩展超高阶位模型的计算方法 ,详细讨论了数值解算过程中的稳定性和可靠性问题。以 EGM96和 GPM98CR模型作为参考模型 ,在全球意义上分别解算得到 MOD99a( 360阶 )、MOD99b( 72 0阶 )和 MOD99c/d( 1 80 0阶 ) ,将系列模型 MOD99a/b/c/d同中国地区 72个 GPS水准大地水准面和全球海洋 1 2个地区的卫星测高大地水准面进行了比较 ,并通过功率谱分析方法检验了 4组模型的有效性和可靠性。

Geopotential modeling is one of the most active research field in physical geodesy. Based on the state of the art of the techniques used for the development of geopotential model, this paper presents the method of extending ultra high degree geopotential model using altimeter derived marine gravity anomalies on a global scale and the local data at high resolution in China. Particular attention is paid to the stability and reliability of the numerical solutions. Using EGM96 and GPM98CR as start models, we have fulfilled the calculation of four ultra high degree geopotential models MOD99a (to degree and order 360), MOD99b (to degree and order 720) and MOD99c/d (to degree and order 1 800). The models have been compared to GPS leveling and altimeter measured geoidal undulations. They are also validated by examining the gravity anomaly degree variance which is implied by the model coefficients.