辅助北斗技术的捕获空间计算和误差分析

[摘要] 结合辅助北斗定位技术的辅助信息类型，提出了北斗GEO和NGEO卫星在星历辅助条件下的卫星信号载波频率和码相位的估计方法，在此基础上重点研究了估计得到的载波频率和码相位的不确定度，并针对粗时间和精时间这两种典型的辅助定位技术进行了算例分析。研究结果表明：粗时和精时辅助能有效减少捕获搜索空间；引起载波频率搜索范围不确定度的因素是时钟频偏和接收机动态，而引起码相位搜索范围不确定度的因素是辅助时间精度和辅助位置误差。

[关键词] 辅助定位技术；粗/精时间辅助；载波频率和码相位；捕获搜索范围

[Abstract] With the help of assisted data of the A-BeiDou system, a method is proposed to estimate the shift of carrier frequency and pseudo-code phase of the Geostationary Earth Orbit (GEO) and Non-Geostationary Earth Orbit (NGEO) satellites. We analyze the uncertainty of the estimated value of carrier frequency and pseudo-code phase. Finally, two typical assistant positioning technologies—coarse time and fine time assisted positioning—are analyzed. Simulation shows that assisted data reduces the acquisition searching space; the clock bias and receiver dynamic are two important factors that cause the error of carrier frequency; and assist time precision and assist position error are two key factors that led to the error of code phase.

[Keywords] tassisted positioning technology; coarse time and fine time assisted; carrier frequency and pseudo-code phase; search range capture