由CHAMP星载GPS相位双差数据解算地球引力场模型

Determination of Earth Gravity Field Model from GPS Phase Double-Different Data Onboard CHAMP

利用7 d的CHAMP星载GPS相位观测数据和48个IGS跟踪站的观测数据,构造星地双差相位观测量,进行GPS数据预处理;利用CowellⅡ数值法进行轨道积分和分块Bayes最小二乘参数估计,解算了地球引力场位系数。该模型与EGM96相比(70阶次),大地水准面起伏差异最大为2.872 m,差异精度为0.522m,平均差异为-0.003 m,这说明本文解算的地球重力场模型与EGM96没有系统性差异。

The satellite-ground double differential phase observation of onboard GPS is given to determine the earth gravity model from GPS phase data onboard CHAMP and observations of 48 IGS tracking sites. The Cowell II numerical orbit integration and the partitioned Bayesian least squares estimation are used to calculate the spherical harmonic coefficients of the earth gravity field to 70 degrees. The maximum difference of geoid undulation between the model and EGM96 （to 70 degrees） is 2. 872 m. The difference accuracy of geoid undulation is 0. 522 m and the average difference is -0. 003 m. These indicate that there is no systematic difference between the model and EGM96.