改进包络模型的GNSS完好性监测阈值设计

Design of GNSS Integrity Monitoring Threshold Based on Improved Envelope Model

多路径是影响卫星导航完好性监测阈值设计的重要因素,针对传统高斯包络阈值设计易受多路径影响存在标准差膨胀过大、系统可用性降低问题,提出一种改进包络模型的阈值设计方法。通过对多路径误差产生原因及分布特点进行分析,建立了伪距误差非正态分布情况下的改进包络模型。试验结果证明,该模型可有效估计出伪距测量误差的标准差,能够辅助设计出更加准确的完好性监测阈值,提高了系统完好性监测水平。

Multipath was one of the most important factors that influenced the design of satellite navigation integrity monitoring threshold, aiming at the problem that the traditional Gauss envelope threshold design was easy to be affected by muhipath, which lead to the excessive expansion of standard deviation and the reduction of system availability, so an improved threshold design method of envelope model was put forward. By analyzing the causes and distribution characteristics of multipath error, an improved envelope model of pseudorange error was established under the condition of non normal distribution. The test results showed that the model could effectively estimate the standard deviation of the pseudorange measurement error and assist to design more accurate integrity monitoring threshold, and it could also improve the system integrity monitoring level.