GBAS差分定位中新增卫星引起高度跳变的抗差估计解决方案

在 GBAS 伪距差分定位实际应用中，出现在某时刻突然产生差分定位高度值异常跳变的现象。经过对实际试飞数据的深入分析，发现根本原因是该时刻新增卫星的伪距误差过大， 导致生成了误差较大的差分修正量。针对此问题，传统的解决方法为延长接收机对卫星锁定时间的最小阈值至固定值 60 s，但该方法仅为依据实践经验取值，较为简单原始，缺乏理论依据。本文所述的组合抗差估计算法能够极大缩短接收机伪距的收敛时间并能适当提高伪距精度，将其应用到新增卫星伪距测量值的预处理中，并通过后续试验验证，确保此问题得到更好解决。

Anti-Error Estimation Solution of Altitude-Jump Problem Caused by New-Locked Satellites in GBAS Differential Positioning

In the practical application of the GBAS pseudo-differential position, there had been abnormal Altitude-jump phenomena in the differential positioning process at some time. After some detailed analysis for the real flight-tests data, the primary cause of the problem was the excessive pseudo-range error of the new-locked satellites at this time and it produced the differential correction which had large error. In response to this question, the traditional solution was to prolong the minimum threshold of the receiver lock-in time to fixed 60 seconds, but this method was merely based on practical experience, it was relatively simple and crude, lacked of theoretical basis. The combined anti-error estimation algorithm described in the paper could greatly shorten the convergence time of the receiver pseudo-range and improve the pseudo-range accuracy properly. By applying this algorithm to the preprocessing of the new-locked satellites pseudo-range measurements, then through the follow-up test verification, we ensured this problem had been thoroughly solved.