BDS-3新频点B1C/B2a动态数据特性及PPP精度分析

通过载噪比(CNR)、数据完整率、伪距与载波相位观测值噪声和伪距多路径效应四个指标对北斗三号卫星导航系统(BDS-3)新频点B1C/B2a车载动态数据的特性进行了分析，测试了BDS-3新频点动态精密单点定位(PPP)的性能，并与其它全球卫星导航系统(GNSS)进行了对比. 试验结果表明，BDS-3新频点B2a平均CNR优于北斗卫星导航系统(BDS)其它频率，但略差于GPS L5；相较于其它GNSS，BDS数据完整率相对较高，其中BDS-3 B2a新频点数据完整率最高；BDS-3 B2b伪距观测值噪声最小，B1C和B2a伪距观测值噪声约为B2b信号的3倍，但不同频率相位观测值噪声处于同一量级；对于伪距多路径而言，BDS-3 B1C/B2a 信号略小于B2b 信号. 总体而言，GPS L5信号抑制多路径效应的能力最强. 在动态PPP性能方面，BDS-3 B1C/B2a双频组合动态PPP定位精度最优，其三维(3D)均方根(RMS)误差为0.439 m，相比BDS B1I/B3I、GPS L1/L2、GLONASS G1/G2和Galileo E1/E5a双频组合PPP，其精度改善率分别为49%、56%、81%和42%. 

BDS-3 dynamic data characteristics for new signals of B1C/B2a and PPP accuracy analysis

The vehicle dynamic data characteristics for BDS-3 new signals of B1C/B2a are analyzed using four indices, i.e. carrier noise ratio (CNR), data integrity rate, observation noise and multipath. The kinematic precise point positioning (PPP) performance for BDS-3 new signals is also tested and compared with the other GNSS. The test results show that the average CNR of BDS-3 B2a new frequency is better than those of the other BDS frequencies, but slightly worse than that of GPS L5. The data integrity rate of BDS is relatively higher compared with the other GNSS. Further, the data integrity rate of the BDS-3 B2a new frequency is the highest. The noise of BDS-3 pseudorange observation at B2b frequency is the lowest, and the pseudorange observation noise at B1C and B2a frequencies is about three times of that of the B2b signal. However, the noise of phase observations at different frequencies is in the same level. For pseudorange multipath, the BDS-3 B1C/B2a signal is slightly smaller than the B2b signal, and overall, the GPS L5 signal has the strongest ability to suppress the multipath. In terms of kinematic PPP performance, the BDS-3 B1C/B2a dual-frequency combined kinematic PPP achieves the best positioning accuracy with a three-dimensional root mean square error of 0.439 m. Compared with the BDS B1I/B3I, GPS L1/L2, GLONASS G1/G2, and Galileo E1/E5a dual-frequency combined PPP, the accuracy improvement rates are 49%、56%、81% and 42% respectively.