不同平滑时间常数对载波平滑码伪距结果的影响分析

伪距和载波相位是接收机的两个基本距离测量值，两者既有明显区别，又呈互补特性。伪距测量值包含钟差、大气延迟等各种误差，但是它真实反应卫星与接收机之间的距离；载波相位测量值含有整周模糊度，但是它非常平滑，精度很高。此外，多径效应对码伪距测量值的影响也远远大于对载波相位测量值的影响。目前，业界通常采用载波平滑码伪距的方法整合码伪距和载波测量的优点，输出一种既无模糊度又相对平滑的伪距测量值。通过设定不同的平滑时间常数和添加电离层模型对载波平滑码伪距的平滑结果进行分析，从而评估滤波器在不同时间常数条件下的性能，最终为平滑时间常数的选择提供决策依据。

Analysis of Influence on Different Smoothing Time Constant on Carrier Smoothing Pseudo-Range Results

Pseudo-range and carrier phase are two basic range measurement values of receiver, which are obviously different and complementary. Pseudo-range measurement contains various errors such as clock difference, ionospheric delay and so on, but it reflects the distance between satellite and receiver. Carrier phase measurement is circumferential ambiguity, but it is very smooth and accurate. In addition, the multipath effect has much more influence on the pseudo-range than the measurement of carrier phase. At present, the industry usually adopts the Hatch filter combining the advantages of pseudo-range and carrier measurement to output smoothed pseudo-range without ambiguity and relative smooth. By setting different smoothing constant and adding ionospheric model, the smoothing results are analyzed, so as to evaluate the performance of the filter, and finally provide a decision basis for the selection of smoothing constant.