北斗三号观测数据质量及定位精度初步评估

开展BDS-3观测数据质量评估对于即将到来的BDS-3应用研究至关重要。本文从载噪比、伪距多路径及观测噪声3方面评估了BDS-3卫星的观测数据质量，在此基础上分析了其标准单点定位和短基线相对定位性能。初步评估结果表明：在载噪比方面，BDS-3卫星的B1I频点比BDS-2卫星高3~4 dB/Hz，B3I频点最高，其余频点大小相当；在多路径方面，BDS-3卫星伪距B2a、B2b和B3I与BDS-2的B3I大小相当，B1I和B1C与BDS-2的B1I、B2I大小相当，且BDS-3各频点的伪距多路径组合中不存在明显的与高度角相关的伪距偏差；在观测值噪声方面，BDS-3卫星与BDS-2卫星各频点大小基本相当。相比于仅使用BDS-2卫星，增加BDS-3卫星可以改善几何图形结构，一定程度上提高伪距单点定位和短基线相对定位的精度。

Preliminary analysis of observation quality and positioning precision for BDS-3 satellites

Analysis of the BDS-3 observation quality is very important for the upcoming relevant applications and research of BDS-3. This paper evaluates the observation quality of BDS-3 satellites, including the carrier noise ratio (C/N₀), pseudo-range multipath, observation noise, and analyzes the precision of single-point positioning (SPP) and short-baseline relative positioning. The results show that the average C/N₀ values for B1I of BDS-3 satellites are 3~4 dB/Hz higher than those of BDS-2 satellites. In terms of BDS-3 satellites signals, the average C/N₀ values for B3I is the highest and the others are sizable. In the aspect of pseudo-range multipath values, B2a/B2b/B3I of BDS-3 working satellite and B3I of BDS-2 satellites are sizable, and those are slightly lower than that of B1I/B1C of BDS-3 satellites and that of B1I/B2I of BDS-2 satellites. As for observation noise, BDS-3 satellites and BDS-2 working satellites are on the same level. The precision of positioning that used BDS-2 and BDS-3 satellites is slightly greater than that only used BDS-2 satellites because of improving the observation geometry.