基于扩展卡尔曼滤波的GPS信号跟踪技术

提出一种基于扩展卡尔曼滤波的GPS信号跟踪方法,通过扩展卡尔曼滤波器,得到基于相干积分支路的滤波模型,有效地削弱常规GPS跟踪环路中的跟踪误差,增强接收机的抗干扰性能,提升其在信号较弱位置下环路的跟踪性能,对加入惯性信息条件下惯性信息对系统所产生的影响做了相应的分析研究。通过仿真对比结果可以知道:当处于弱信号条件时,与通常用到的GPS信号跟踪方式相比,基于扩展卡尔曼滤波的信号跟踪算法可以有效提升跟踪的精度。

GPS Signal Tracking Technique Based on Extended-Kalman Filter

In view of the traditional GPS receiver large tracking error, this paper presents a tracking method based on Extended Kalman Filter. The method uses receiver I/Q branch coherent integration measurements, then get the filter model of the baseband signal processing. This method reduces the estimation error of GPS tracking loop parameters effectively, and improves anti-jamming capability under weak signal. The influence of INS when INS was added is presented too. The simulation results of low noise ratio environment show that the signal tracking algorithm, which based on I/Q branch coherent integration, can ensure tracking precision.