基于GPS精密单点定位技术的L2C信号分析

基于精密单点定位（precise point positioning, PPP）技术处理2016年年积日1～7 IGS网中27个测站的高频数据，并直接在位置域研究使用L2C信号代替传统的L2P信号构成双频无电离层组合的精度改善情况。实验结果表明，P1/L2C组合观测值相较于传统的P1/L2P组合PPP动态定位结果在E和N方向有7.4%的精度提升，U方向改善了4.4%。另外，L2C信号跟踪稳定、不易失锁等特点有利于保持卫星观测弧段的连续性，从而有助于PPP模糊度参数的收敛和定位精度的提高。

Analysis of L2C Signal Based on GPS Precise Point Positioning

With the modernization of GPS, there are currently 7 Block ⅡR-M satellites and 12 Block ⅡF satellites capable of broadcasting L2C signals, achieving initial operational capability. We process the high-rate data of 27 stations in the IGS network during DOY 1-7 of the year 2016 using precise point positioning (PPP). The improvement of L2C-based over L2P-based ionosphere-free combinations is directly examined in position domain. The experimental results show that the P1/L2C combination observations exhibit 7.4%, 7.4% and 4.4% accuracy improvements in the east, north and up components, respectively, compared to the traditional P1/L2P combination PPP dynamic positioning results. In addition, L2C signals can be stably tracked and do not easily lose lock, which is appreciated for preserving the continuity of satellite observation and for solving ambiguities in PPP data processing.