长码快速直接捕获中卫星信号传播时延估计

卫星导航定位系统中,辅助长码快捕的一个最重要的信息是时间信息,卫星信号传播时延估计是提供先验时间信息,减少时域搜索范围的一个重要方面．基于用户和卫星的概略位置,给出了适用于不同类型导航星和不同用户场景的卫星信号传播时延估计算法．数值计算表明,算法能够大大压缩不同导航星和不同场景用户之间传播时延的不确定范围,即使在用户与卫星位置误差较大的恶劣应用背景下也能将不确定范围压缩一半,从而有效地辅助长码快捕的实现．

Estimation of Satellite Signal's Propagation Delay for Fast and Direct Acquisition of Long Cycle and High Rate Pseudo-Random Code

In satellite navigation and positioning system, time is important information for fast and direct acquisition of long cycle code, one of its important aspects is the uncertainty compression of signal's propagation delay to reduce time search range. Based on coarse data of positions of user and satellite, estimation algorithms of propagation delay between different satellites and users are given. Simulation results indicate that the algorithm can reduce the delay's uncertainty range greatly, even with great position errors the uncertainty range still can be reduced to the half, and is effective for the fast acquisition of long cycle code.