基于钟差预测辅助的TDCP测速研究

Research on TDCP velocity measurement based on clock bias prediction

针对重特大灾害发生时密集废墟或城市峡谷造成的信号频繁遮挡,以及由高压电力通讯设施或发生地震等灾害时产生的复杂强电子干扰而无法测速的问题,基于时间序列理论,对接收机钟差进行短期预测,并将钟差预测辅助载波相位时间差分(time-differenced carrier phase,TDCP)算法进行解算,以实现恶劣环境下载体获取三维测速信息的功能。由于TDCP避免了整周模糊度解算的问题,能够有效削弱具有明显时间序列的共模误差,具有短期精度高的特点,因此,本文利用少于4颗的GPS有效卫星星座,通过ARIMA模型得到一定精度的接收机钟差短期预测值,来扩充测速观测条件,并结合TDCP获取短期较高精度的测速结果。实测数据表明,本方案能在80 s的时间尺度内,在有效卫星数不足的情况下,无需增加额外硬件即可满足载体测速需求,且测速精度在动态条件下可以达到分米级。

In order to solve the problem of frequent blocking of signals caused by dense debris and urban canyons,and complex strong electronic interference caused by high-voltage power communication facilities or earthquakes during the occurrence of serious and super-large disasters,the receiver clock bias was predicted in a short term based on the time series theory,and the clock bias prediction value was used to assist the timedifferenced carrier phase (TDCP) algorithm to realize the function of obtaining three-dimensional velocity measurement information for downloads in severe environments. Because the TDCP avoided the problem of ambiguity resolution for the whole cycle,it could effectively weaken the common mode errors with obvious time series,and had a characteristic of high accuracy in a short term,so that less than four GPS active satellite constellations were used to obtain short-term prediction values of receiver clock bias with certain accuracy through ARIMA model to expand the observation conditions of velocity measurement,and short-term high-accuracy velocity measurement results with TDCP. The measured data showed that this scheme could meet the requirements of carrier speed measurement without adding additional hardware in the time scale of 80 s and under the condition that the number of effective satellites was insufficient. The speed measurement accuracy can reach the decimeter level under dynamic conditions.