单差载波相位自主完好性监测算法

An Autonomous Integrity Monitoring Algorithm for Single Differential Carrier Phase

应用载波相位差分定位时,由于多路径误差、卫星信号遮挡、卫星故障等原因,易造成载波相位测量值发生偏差和周跳,因此必须进行完好性监测。研究了利用单差载波相位测量值进行载波相位完好性监测的方法,固定整周模糊度值之后,利用最小二乘残差构造检验统计量,根据虚警概率和观测到卫星个数设定门限值,对单差载波相位测量值进行监测。分析了垂直保护级和漏警概率、卫星个数的关系。实验结果表明,虚警概率取为10-7/历元时,算法能有效检测测量偏差,对小至0.4周的偏差,比原有算法检测能力较强;漏警概率取为10-6/历元,垂直告警限值取为1.1m时算法满足可用性要求,增加1颗观测卫星能使垂直保护级降低约2cm。

Aimed at the problem that Bias and cycle slips of Carrier Phase measurements will occur because of multipath error, satellite signals blockage, satellite failure and other factors in utilizing differential carrier phase positioning, this paper proposes an integrity monitoring necessarily. The carrier phase integrity monitoring algorithm is researched based on single differential carrier phase measurements. After carrier phase inter ambiguities are determined, test statistic is constructed by using the method of least squares and threshold set according to the false alarm probability and number of observed satellites to test carrier phase measurements. Relationship between vertical protection level, satellite geometry and miss detection probability is analyzed. The experiment results indicate that when the false alarm probability is 10^-7 , the algorithm in this paper can detect measure bias effectively, and is more effective when the bias is as small as 0.4 cycle. When the missing alarm rate is 10 6 and the vertical protection level is 1.1 m, the algorithm meets the requirements of availability, and the addition of 1 observation satellites can reduce the vertical protection level by about 2 cm.