地球重力模型及中国大陆重力场的计算

THE EGM96 AND ITS CHINA GRAVITY CALCULATION

融多颗卫星数据、地面重力值和其它资料一起的地球重力模型EGM 96 ,为研究中国大陆的重力场及相关问题提供了一个高精度 36 0阶的球谐系数。在分析EGM 96的基础上 ,计算并简单解释了中国大陆的自由空气异常和布格重力异常。计算所得重力场的精度和分辨率大大高于常用的1∶140 0 0 0 0

EGM96, which was mainly developed by NASA, NIMA and the Ohio State University, is a degree up to 360 spherical harmonic cofficients of earth’s gravitational potential model. This high accurate model was calculated from satellites data, which include altimetry data, tracking data, and so on. GPS data, 30′×30′ surface gravity data, etc. The major advancements in EGM96 were the incorporation of all data into 360×360 geopotential solution, improved model accuracy, offered some important by-products and a new calculation method for the high-degree solutions. In this paper, we firstly introduced the earth gravity model-EGM96, then calculated and interpreted the free-air gravity anomaly of mainland of China using EGM96. In addition, the digital topographic data was used to obtain Bouguer gravity anomaly in the same area. The geological explain was made in the paper.