GNSS钟差估计中的两种测站选取策略分析

Analysis of Two Station Selection Strategies in GNSS Satellite Clock Offsets Estimation

格网控制概率选站方法和不规则三角网(TIN)选站方法均可同时顾及测站的几何分布和数据质量,现有研究仅采用其中一种方法对单一系统测站进行选取,缺少对两种方法的比较分析和多系统测站选取的研究。鉴于此,将两种方法应用于四系统钟差估计的测站选取。一周实验结果表明,在一定数量范围内,测站数增加,测站几何构型改善明显,当超过60个测站时,两种方法选站的加权GDOP值和解算的钟差精度变化缓慢。两种选站方法解算的GPS/Galileo卫星钟差精度相当,选取30~50个测站时,前者解算的GLONASS卫星钟差精度优于后者5.3%~13.2%;选取30~70个测站时,前者解算的BDS-3卫星钟差精度优于后者10.3%~26.2%,因此选取测站数量不超过70个时,应优先采用格网控制概率选站方法,测站数量超过70个时,两种方法均可选用。

Both grid control probabilistic station selection method and irregular triangular network(TIN) station selection method can take into account the geometric distribution of stations and data quality at the same time. The existing research only uses one method to select stations for a single system, and lacks the comparative analysis of two methods and the station selection research of multiple systems. In view of this, we applied two methods to select stations for clock offsets estimation of four systems. One week’s experimental results show that within a certain number of stations, the number of stations increases, and the geometric configuration of stations improves significantly. When there are more than 60stations, the weighted GDOP value of two methods and the clock offsets accuracy of solution change slowly. The accuracy of GPS/Galileo satellite clock offsets calculated by the two station selection methods is equivalent. When 30~50 stations are selected, the accuracy of GLONASS satellite clock offsets calculated by the grid control probabilistic station selection method is better than that of TIN station selection method by 5.3%~13.2%. When 30~70 stations are selected, the BDS-3 satellite clock offsets accuracy is better than that of TIN station selection method by 10.3%~26.2%. When the number of selected stations does not exceed 70, the grid control probabilistic station selection method should be used at first,when the number of stations exceeds 70, both methods can be used.