一种新的高动态条件下实时高精度伪距计算方法

A New Method of Real-time High Precision Pseudorange Calculation in High Dynamic Circumstance

针对高动态全球导航卫星系统(Global Navigation Satellite System,GNSS)仿真系统中伪距计算精度与实时性的矛盾,提出了一种基于三阶Hermite插值的实时高精度伪距计算方法。首先通过插值算法获得卫星轨道并调整误差项计算顺序来优化伪距计算方法,然后在已知两个节点处的伪距及其导数后,采用三阶Hermite插值算法计算伪距变化模型参数,其中伪距导数通过二阶Lagrange插值多项式的求导公式求得。高动态仿真结果表明,在时间间隔取1s时,最大伪距误差为0.638mm,标准差为0.172mm。

In highly dynamic GNSS simulation systems,since there is a contradiction between precision and calculated volume,a method of real-time high precision pseudorange calculation based on the third-order Hermite interpolation is proposed.In this method,a satellite orbit is computed by an interpolation algorithm and the sequences of the error computation is changed to optimize the pseudorange calculations.Then,by knowing the pseudoranges and derivatives for two nodes,the parameters of the pseudorange change model was computed by a third-order Hermite interpolation algorithm.The pseudorange derivative was obtained by the second order derivative Lagrange interpolation formula.The highly dynamic simulation results show that when the time interval is 1s,the maximum pseudorange error is 0.638 mm,and the standard deviation is 0.172 mm.