电离层对电磁波是色散介质。CAPS信号在电离层中传播时受色散效应作用，不同频率成分所受延时不同，导致测距信号的失真，从而引起测距误差增加。特别是CAPS采用40 MHz的宽带测距信号时，这种色散失真影响会更明显。目前研究主要考虑电离层对卫星导航信号的群速度时延误差，未考虑色散失真带来的测距误差。本项目研究CAPS的40 MHz宽带测距信号受电离层色散失真引起的测距误差，从理论分析、计算机建模、Monte Carlo仿真和生成实际信号进行试验分析来开展研究，分析和计算电离层色散失真引起的CAPS信号的测距误差量级，并探索减小此误差的方法。

Ionospheric is a dispersive medium for electromagnetic wave. The CAPS signals which propagate through the ionosphere are influenced by the dispersion effect. The different frequency components of the CAPS signal suffers different delay, resulting in a distortion of the ranging signal, and causing the ranging error. Considering CAPS using 40 MHz bandwidth signal, such dispersion distortion effects will be more pronounced. The current research mainly consider the ionospheric delay error which causes the group velocity of the satellite navigation signals, but rarely consider the influence of dispersion distortion ranging error. This project examines the ranging error caused by ionospheric distortion of the CAPS 40 MHz spread spectrum signal. And the theoretical analysis, computer modeling and Monte Carlo simulation method is used to calculate the ranging error caused by the ionospheric dispersion distortion of the CAPS 40MHz spread spectrum signal. And the method to reduce this error will be studied.