【摘要】 低低卫星跟踪卫星的观测量是两低轨卫星的星间距离或星间速度,星间加速度由星间速度通过数值微分导出,用星间加速度作为观测量可以避免解算卫星运动的变分方程,简化观测方程的建立,但数值微分会使观测噪声放大,从而影响重力位的解算精度.为了定量给出星间加速度观测模式的精度,本文分析并模拟验证了数值微分公式计算星间加速度的精度,导出了基于星间加速度的一般形式的观测方程,模拟计算了基于星间加速度的重力位模型.结果表明,采用星间加速度观测模式的解算精度要明显低于星间速度观测模式的解算精度.更多还原

【Abstract】 In the low-low satellite to satellite gravity mission, the intersatellite range and range-rate data are the observable values, while the intersatellite acceleration can be derived from the range-rate through digital differential. Using acceleration data, people can avoid solving the variational equations of the satellite motion and simplify the observation equations. But on the other side, the digital differential will amplify the observation noises and finally affect the solved geopotential accuracy. In order to give a quantitative answer, this paper analyses and tests the accuracy of calculated acceleration by digital differential, derives the general observation equations with the intersatellite acceleration and simulates the geopotential solution based on the acceleration data. The results show that the solution accuracy by using the acceleration observation is much lower than the accuracy obtained from the range-rate observation.更多还原