星载GPS测量数据预处理方法研究

针对低地球轨道(LEO)卫星星载全球定位系统(GPS)接收机应用的特点,对星载GPS测量数据误差及其对周跳探测的影响进行了分析,提出TurboEdit数据预处理方法中周跳探测算法的改进算法。在原周跳判断算法的基础上,通过引入与测量数据观测高度角相关的加权系数,将周跳探测与测量误差紧密联系起来。根据观测高度角的变化对测量数据误差进行估计,并根据估计情况对加权系数取值,从而实现对周跳探测算法进行调节,达到降低周跳探测失误率的目的。增加参与定轨计算的观测数据量,提高了低轨卫星连续定轨的能力。通过GRACE编队卫星实测数据对改进算法进行了仿真验证。

Research on Pre-processing Method of Satellite Borne GPS Measurement Data

In connection with the application characteristics of low earth orbit (LEO) satellite space-borne GPS receiver, this article analyzes the influence of GPS measurement data error on cycle-slip detection, and then proposes a modification to the cycle-slip detection algorithm in the TurboEdit pre-processing method. A weighting factor which is closely related to the measurement data observation elevation angle is introduced to the original algorithm, which enables the cycle-slip detection process to establish a close connection with measurement errors. The weighting factor estimates measurement error according to changes in the elevation angles for data observation measurements, and then adjustes the cycle-slip detection process. The modified algorithm not only reduces the fault rate of cycle-slip detection, but also increases the amount of observation data which will participate in LEO satellite orbit determination, and promotes the autonomous ability of orbit determination. Finally, the modified algorithm is verified by real measurement data of GRACE satellite formation.