卫星导航接收机误差分析

Error Analysis for Satellite Navigation Receiver

卫星轨道、星钟误差、导航信号空间传播误差和用户接收机处理误差是影响北斗卫星导航定位精度的主要因素。针对北斗导航接收机的特点,重点描述了接收机伪码跟踪环路及伪码数控振荡器(NCO)量化过程中所带入的误差分量,对3类伪码跟踪鉴相器的随机误差进行了分析,给出了伪码跟踪环路滤波器带宽与伪距测量误差的关系以及接收机误差控制策略。基于北斗接收机通道时延值测量误差及通道时延漂移,提出了一种接收机通道时延测量方法,可使接收机通道时延测量误差优于1 ns。

The accuracy of navigation receiver depends on the errors of the orbits and clocks of the satellites,space propagation and the receiver＇s processing of navigation signals.The errors induced by the quantization of numerically controlled oscillators（ NCO）and channel tracking are described based on the features of Beidou receivers in this paper. The random errors of three types of PLL discriminators are analyzed.The relationships between the bandwidths of PLL filters and the measurement errors are given,which can be used for the error control in the designs of the Beidou receivers.Taking the time-delay and its drift into account,a method of time-delay measurement for the receiver＇s channels is proposed,which can implement the accuracy within 1 ns.