【摘要】 从两个方面模拟研究了低低卫-卫跟踪观测技术恢复地球重力场的空间分辨率.利用重力位系数作为扰动量,积分30天的轨道,研究重力位系数变化引起低低卫-卫跟踪星间距离和速率变化,结果表明,对于地球重力场模型EGM96的前12 0阶,99 8%和97%的位系数扰动引起星间距离和速率变化的均方差大于1×10 - 5m和1×10 - 7m s ,并且星间距离观测值对地球重力场的反应更为敏感.不考虑非保守力误差的影响,用随机误差为1×10 - 5m和1×10 - 6 m s的星间距离和速率变化作模拟观测量,恢复了78阶地球重力场位系数,结果表明,采用随机误差为1×10 - 5m的星间距离恢复地球重力场的精度明显高于1×10 - 6 m s的星间速率结果,但是如果考虑非保守力误差影响,则星间测速的优越性大大增强.更多还原

【Abstract】 In this paper, we used numerical simulation study the resolution of the Earth gravity field recovery through the low-low satellite to satellite tracking technology in two aspects. First, using geopotential coefficients as perturbation source, we studied the changes of SST range and range rate due to geopotential coefficient variation over 30-day integral orbit, the results showed that 99.8% and 97% of the geopotential coefficients produced perturbations with a root-mean-square larger than 1×10 -5 m and 1×10 -7 m/s on the range and range rate, which was based on the EGM96 gravity field truncated at degree and order 120, the effect of SST range on gravity field recovery was more sensitive than rang rate. Second, we added 1×10 -6 m/s SST range rate and 1×10 -5 m range random noise to the simulated observation, and recovered gravity field to degree and order 78 without considering the non-conservation force errors. The results showed that we could get higher precision of the gravity field coefficients by 1×10 -5 m range noise than 1×10 -6 m/s range rate noise, but considering the non-conservation force errors, the range rate would have more advantage over range.更多还原