极地BDS⁃3数据质量与多频定位性能分析

Analysis of data quality and multi⁃frequency positioning performance of BDS⁃3 in polar region

为分析BDS⁃3在极区的数据质量与定位性能,本文基于MGEX南北两极附近4个测站连续7 d的观测数据进行数据质量评估,并分析不同双频/三频组合精密单点定位(PPP)定位性能。结果表明,BDS⁃3在两极平均可见星数约为10颗,位置精度因子(PDOP)为1.7,南、北两极数据完整率分别约为96.2%、90.1%,信噪比两极相差不大,均为45 dB⁃Hz,MP RMS为27~35 cm;BDS⁃3双频/三频PPP在极区能达到收敛后1~3 cm的定位精度,其中三频较双频定位精度有一定提升;三频无电离层两两组合(IF1213)U方向提升最大,约为21.8%,三频非差非组合(UC123)平均提升约8.3%;IF/IF1213组合收敛时间分别为15.4、18.3 min,优于UC/UC123的28.0、28.2 min。

In order to analyze the data quality and positioning performance of BDS⁃3 in the polar region,this paper evaluates the data quality based on the observation data of four stations near the north and south polar regions of MGEX during 7 consecutive days,and analyzes the positioning performance of different PPP combinations about dual⁃frequency and tri⁃frequency.The results show that the average number of visible satellites at the region of BDS⁃3 is about 10,the value of PDOP is 1􀆰7,the data completeness is about 96􀆰2%and 90.1%at the south and north polar regions,respectively.The value of SNR is a little difference between north and south region,both around 45 db⁃Hz,and the MP RMS is between 27~35 cm.In the polar region,the positioning accuracy of the BDS⁃3 PPP􀆳s dual⁃frequency and tri⁃frequency can reach 1~3 cm after convergence,and the positioning accuracy of the tri⁃frequency PPP is improved to a better extent compared with that of the dual⁃frequency PPP.The improvement accuracy of the IF combination in the direction of U is the largest,which is about 21.8%,and the average accuracy increase of UC combination is about 8.3%.The convergence time of dual⁃frequency and tri⁃frequency IF combination is 15.4 and 18.3 min respectively,which is better than 28.0 and 28.2 min of UC.