基于星载GPS双频观测值的简化动力学定轨方法

论述了基于低轨卫星星载GPS双频观测值的精密单点定位技术的简化动力学定轨方法的数学模型,分析了简化动力学定轨中的关键问题--伪随机脉冲的设置问题及其对定轨精度的影响.最后结合CHAMP卫星实测GPS数据,利用简化的动力学定轨方法对CHAMP进行定轨.算例结果表明,伪随机脉冲的设置可以有效吸收力学模型误差的影响,因而定轨精度较稳定.根据一个星期的CHAMP星载GPS跟踪数据计算的CHAMP轨道,同德国慕尼黑工业大学TUM计算的CHAMP轨道相比,均方根误差(RMS)在10 cm以内.

Reduced-Dynamic Orbit Determination Using Dual-Frequency Onboard GPS Observations

The principle and the mathematical model of reduced-dynamic precise orbit determination(POD) are discussed based on precise point positioning(PPP) technique by zero-differenced dual-frequency P codes and epoch-wise differenced carrier-phase data.Then the key issue in the reduced-dynamic POD,i.e.the pseudo stochastic pulses and their impact on orbit determination accuracy are analyzed.Finally,real CHAMP GPS data are utilized to demonstrate the accuracy by the reduced-dynamic POD.The results show that the accuracy of reduced-dynamic POD is relatively high and the orbiting results are comparatively stable by using pseudo-stochastic pulses.Compared with CHAMP orbiting results of TUM solutions,the CHAMP orbiting results of one week in 2003 by using reduced dynamic POD method show that the RMS is within 10 cm.