区域测站数对BDS实时卫星钟差估计的影响分析

Performance Analysis of Real-Time BDS Clock Estimation for the Number of Regional Stations

地面测站的数量及分布会影响实时卫星钟差估计的精度和可靠性。鉴于目前BDS主要为亚太地区提供服务,均匀选取中国区域内8~24个实时监测站,分析区域测站数与BDS实时卫星钟差估计精度的关系。结果表明,当测站数小于16个,IGSO/MEO卫星在中国区域内被观测的弧长不全,实时钟差精度和定位精度较差;当测站数达到16个,中国区域内可观测的BDS卫星弧长覆盖饱和;当测站数达到17个及以上,实时钟差精度达到0.15ns,平面定位精度达到0.3m以内,高程定位精度达到0.4m以内,且钟差和定位精度随着测站数的增加不再明显提高。

The number and distribution of ground stations affects the accuracy and reliability of realtime satellite clock estimation.As current BDS mainly provides services to the Asia-Pacific region,the article selects 8,12,18 and 24 real-time ground monitoring stations distributed equally in the China region to analyze the relationship between the number of regional stations and the accuracy of BDS real-time satellite clock.The results show that,when the number of stations is less than 16,the arc length of IGSO/MEO satellite is observed in the Chinese region is not complete,and that real-time clock accuracy and positioning accuracy is poor.When the number of stations reaches 16,the observable BDS satellite arc length is covered in the China region.When the number of stations reaches more than 17,real-time clock accuracy is 0.15 ns,and positioning accuracy is 0.3 mor more in the horizontal direction and 0.4 mor more in the vertical direction;further,real-time clock estimation accuracy and positioning accuracy no longer significantly increases with the number of stations.