关于GBAS完好性统计量最佳门限值验证性研究

Verification Study of Optimum Threshold in GBAS Integrity Statistics

在地基增强系统(GBAS)的差分与完好性监测算法中,伪距差分是经常采用的一种测量差分模式,它在短基线情况下能够有效消除绝大部分空间相关测量误差和时间相关误差,从而能够有效提高机载端定位精度。而在其完好性算法中,统计量门限值的选取是很重要的一个环节,门限值计算公式中虚警率对应的分位数a如何取值,直接决定着最终机载端差分定位结果的好坏。本文通过采集大量的GBAS差分卫星地面站完好性统计量数据进行分析,并以步长“2σ”为间隔依次进行完好性统计量门限值的分析,最终通过比对伪距差分定位结果进一步验证门限值选取“6σ”的合理性。

In the difference and integrity monitoring algorithm of the ground-based augment system,pseudo-range difference is a commonly used measurement difference mode,it can effectively eliminate most of the spatial and timely correlation error in the case of short baseline,thus can effectively improve the positioning accuracy of the airborne terminal.And in its integrity algorithm,the selection of statistical threshold is a very important aspect and the value of quantile a which corresponding false alarm rate in the threshold calculation formula directly determines whether the result of the differential positioning is good or bad.This paper based on conducting data analysis through collecting a large amount of integrity statistics data in GBAS ground station of differential satellite,then through analyzing the threshold of the integrity statistics data and comparing the results of the pseudo-range differential positioning by steps“2σ”,finally verifies the rightfulness of using“6-sigma”as selecting the threshold of the integrity statistics data.