一种新的亚米级星载GPS伪距实时定轨方法

A Novel Submeter-Level Real-Time Orbit Determination Algorithm Based on Space-Borne GPS Pseudorange Measurements

提出了一种新的星载GPS实时定轨方法,该方法以伪距作为主要观测值,通过在卡尔曼滤波模型中设置参数来吸收广播星历中的轨道误差与钟误差,从而实现亚米级精度的实时定轨。采用自主研制的实时定轨软件SATODS对GRACE-A卫星的实测数据模拟实时处理,结果表明：采用本文方法后,实时定轨的位置精度和速度精度（3DRMS）分别可达0.4~0.6 m与0.4~0.6 mm/s;相比于传统的伪距实时定轨精度可提高40%。

A novel real-time orbit determination method based on GPS pseudorange measurements is presented in this paper. In this method, the GPS pseudorange measurements are taken as basic observations, corresponding parameters in the Kalman filter model are set to absorb the errors of broadcast orbits and clocks, thus achieving sub-meter level orbit results. Then a simulative test is carried out to process the space-borne GPS dual frequency pseudo-range data of GRACE- A by using broadcast ephemeris with the auto-developed software SATODS. The test demonstrates that the position and velocity error （3DRMS） of orbit results are reduced to 0.4 ~ 0.6 m and 0.4 - 0.6 mm/s respectively, which means orbital accuracies are improved by 40% compared with the traditional method.