一种顾及DOP值的ARAIM风险优化分配方法

An Optimal Allocation Method for ARAIM Risk Considering DOP Value

  • 摘要: 针对高级接收机自主完好性监测(advanced receiver autonomous integrity monitoring, ARAIM)算法将完好性风险和连续性风险平均分配,导致保护级计算保守的问题,系统分析影响保护级计算的因素,提出了一种顾及精度衰减因子的ARAIM风险优化分配方法,并采用MGEX(multi-GNSS experiment)测站、车载及航空实验3种数据验证该方法的有效性。结果表明,所提方法可实现保护级对定位误差更为紧致的包络,且优于半区间搜索法。相较风险平均方法,3类实验中北斗卫星导航系统(BeiDou satellite navigation system, BDS)保护级的改善率分别为7.5%、11.6%和8.8%。此外,保护级的改善效果与卫星观测几何结构密切相关,不同系统和区域内的优化效果存在差异。对于BDS而言,非亚太地区对应改善幅度优于亚太地区,两区域内的改善幅度分别为3.6 m和1.0 m;在亚太地区,BDS和BDS/GPS组合的改善幅度分别为1.0 m和0.6 m,单BDS提升效果更为显著。

     

    Abstract:
    Objectives The advanced receiver autonomous integrity monitoring (ARAIM) algorithm equally allocates the integrity and continuity risk, which leads to a conservative protection level calculation.
    Methods We systematically analyze the factors affecting the protection level calculation, and propose an optimal risk allocation method for ARAIM considering the dilution of precision (DOP), and verifie the effectiveness of the method using three kinds of data from the multi-GNSS experiment (MGEX) station, vehicle and airborne experiments.
    Results The results show that the proposed method can realize a tighter envelope of the protection level to the position error, and its performance is better than that of the half-interval search method. Compared to the risk-averaged method, the protection level improvement rates of BeiDou satellite navigation system(BDS) in the three types of experiments are 7.5%, 11.6% and 8.8%, respectively. In addition, the protection level optimization effect is closely related to the satellite observation geometry, and the improvement effect varies in different systems and regions.
    Conclusions For BDS, the improvement in the non-Asia-Pacific region is better than that in the Asia-Pacific region, with 3.6 m and 1.0 m respectively in the two regions. In the Asia-Pacific region, the optimization effects in BDS and BDS/GPS are 1.0 m and 0.6 m, respectively, with the single BDS enhancement being more significant.

     

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