静态用户精密授时问题的探讨

 为了提高RNSS授时精度,提出了采用卡尔曼滤波器和小波滤波器对观测值进行联合滤波的方法,对用户时钟钟差,钟漂及老化率进行估计,预测出用户时钟与系统时的差值.在观测到多颗卫星时,理论推导出采用加权的方法可使授时精度得到提高.最后对提出的方法进行了仿真,并与卡尔曼滤波和加权环路滤波进行了比较,结果表明授时精度得到了有效改善,在观测误差较大的情况下仍能保证高精度授时.

Discussion of Precise Time Transfer of Stationary User Terminal

In order to improve the accuracy of time transfer of RNSS (Radio Navigation Satellite System), a novel method of combination of Kalman filtering and wavelet filtering is proposed to estimate the user clock offset, clock shifting and clock aging rate,and predict time bias between user time and system time. When multiple satellites are in view,it is proven that weighing several measurements properly has the characteristic of improving the accuracy of time transfer. At last, the method proposed is simulated under the condition of single satellite and multiple satellites, and is compared with Kalman filtering and weighing-loop-filtering. The result demonstrates that the accuracy of time transfer is improved efficiently and the excellent performance can be kept even under heavy noise situation.