Tianhui-1C卫星数据质量分析及精密定轨

Quality Assessment and Precise Orbit Determination for Tianhui-1C

对Tianhui-1C卫星的星载双频GPS数据进行质量分析,利用伪随机脉冲方法进行简化动力学定轨,采用重叠弧段比较法对其精密定轨精度进行初步分析,并从理论上分析星载GPS接收机由单频改为双频对测图精度的影响。实验表明,Tianhui-1C卫星的星载GPS观测数据完整率优于80%,周跳比优于47,L1频点的多路径误差约0.22m,L2频点的多路径误差约0.23m,LC组合观测值的验后残差RMS优于9.7mm。采用轨道重叠弧段比较法对两个时段共48h的星载GPS数据进行精密定轨精度比较,三维精度优于3.65cm。定轨精度的提高,可使无地面点控制条件下等高线间距(CI)精度提高3.866m,高程误差提高1.171m。

Quality assessment of Tianhui-lC for space-borne dual-frequency GPS is put forward in this paper. The reduced-dynamics satellite orbit determination is based on pseudo-stochastic pulse estimation. The orbit quality tests are performed through orbit overlap comparisons. Then, the influence of the satellite receiver change from single frequency GPS to dual frequency GPS for the satellite photogrammerty is analyzed in theo- ry. The results show that data availability of five types of observations collected by the Tianhui-lC onboard GPS receiver is better than 80~. The ratio of cycle slip is better than 47. The averaged RMSs of MPCs for Pl-code and Pz-code measurements are 0.22 m, O. 23 m, respectively. Two sessions, which have a total of 48 h of space-borne GPS measurements, are compared through orbit overlap comparisons. The orbit quality tests are performed through orbit overlap comparisons with two sessions, in which the orbit accuracy of precise or- bit determination with space-borne GPS measurements can achieve 3.65 centimeters. Increasing orbit accuracy will help improve the accuracy of the satellite photogrammerty without ground control points （CI） precision to 3.866 m, and ellipsoidal height error increase to 1. 171 m.