广播星历更新对实时测速的影响分析

实时获取高精度的载体速度信息在科学研究和生产应用中都具有重要意义。采用TDCP方法可实时获取载体高精度的速度信息。利用传统就近原则选择广播星历数据块,会使得相邻历元所采用的星历数据块不统一,从而导致卫星轨道和钟差不连续。本文首先介绍了TDCP方法的基本原理;然后分析了星历更新引起的卫星轨道和钟差跳变的大小及其对参数估计的影响,并提出了改进的数据处理策略;最后通过实测数据验证了本文方法的可行性,结果表明静态模拟动态模式下单频实时测速精度可达1~3 mm/s。

The Impact of Data Blocks Update in Broadcast Ephemeris on Real-time Velocity Estimation

Real-time precision velocity plays an important role in many fields.Time-difference carrier phase(TDCP)is an effective way to obtain the real-time velocity with high accuracy by differencing successive carrier phases.Thus,it will be affected by the discontinuity of satellite orbits and clocks caused by the updating of broadcast ephemeris.In this paper,we introduced the principle of TDCP at first. Then,we analyzed the spikes magnitude of orbits and clocks as well as their impact on velocity estimation.Finally,we proposed a new data processing strategy,unifying the broadcast ephemeris between successive epochs.A static test was conducted in real-time mode using single frequency GPS data,and the results showed that the accuracy of velocity estimation can reach 1~3 mm/s.