BDS-3卫星信号质量及RTK定位分析

Analysis of BDS-3 signal quality and its RTK performance

为评估北斗三号卫星(BDS-3)信号质量及定位性能,针对BDS-3各频点,使用码减相位和双差相位两种组合观测值分析伪距和相位观测精度;评估了BDS-3和GPS同频观测值之间的系统间偏差;分析了BDS-3/GPS松紧组合单频RTK的定位性能。结果表明,同频条件下,BDS-3伪距观测噪声比GPS更低,相位观测噪声在同一水平;在同类型接收机间,BDS-3/GPS的ISB服从均值为0的正态分布;在RTK定位性能上,单系统仅可实现51~57%的模糊度固定率,多系统可实现90%以上的固定率,改正ISB后的紧组合RTK比松组合RTK在固定率和定位精度上有3.4%和3.2%的提升。总体而言,BDS-3信号质量较好,可与GPS兼容互操作,能够进一步提升GNSS的定位性能。

The third generation of BeiDou navigation satellite system(BDS-3)has realized its global networking.In order to evaluate its signal quality and positioning performance,this article analyzes the noises of code and phase observation by code-minus carrier and double-difference combination at all the signals in BDS-3.Then,the inter-system bias(ISB)between BDS-3/GPS B1 C/L1 is assessed.Finally,the positioning performance of the loosely combined and tightly combined RTK with BDS-3/GPS overlapping-frequency observations is analyzed.The results show that under the overlapping frequency,the code noise of BDS-3 is lower than GPS while the phase noise remains the similar between different system.Between the identical type of receivers,the ISBs between BDS-3 and GPS obey zero-mean normal distribution.In terms of positioning performance,only 51-57%fixed rate can be achieved by single-system RTK while the multi-system RTK corresponds to a higher fixed rate over 90%.The tight combined RTK with ISBs corrected performs better than the loose combined RTK,obviously.The fixed rate and positioning accuracy improves by 3.4%and 3.2%,respectively.In general,BDS-3 performances good in signal quality and can be compatible and interoperable with GPS so the positioning performance of multi-GNSS can be further improved.