一种实时双频电离层修正方法

A Real-time Dual-frequency Ionospheric Correction Method

电离层延迟是影响GPS绝对定位的重要因素。比较常用的电离层延迟修正方法有模型方法和双频方法。模型方法和使用双频码伪距的方法精度有限。使用双频载波相位进行电离层延迟计算需要求解整周模糊度,计算复杂。提出了一种同时使用GPS双频码和载波观测量进行电离层误差修正的方法。使用卫星信号模拟器生成信号并用接收机实时接收,用此方法计算出电离层延迟值,并与真值进行比较,计算误差为厘米级。最后,接收真实卫星信号并计算了真实电离层延迟,并与使用Klobuchar模型方法计算出的电离层延迟进行了比较。

The ionospheric delay is one of the main error sources for GPS absolute positioning.Ionospheric delay models and dual-frequency methods are commonly used.Ionospheric models are based on empirical models,and the accuracy is limited.Dual-frequency ionospheric delay calculation methods,which use code and carrier observations respectively,have their drawbacks.A method of using dual frequency code pseudorange and carrier phase measurement simultaneously are presented to eliminate the ionospheric delay of observation path.Signal simulator was used to generate GPS signal with ionospheric delay.The ionospheric delay was calculated and compared with true value.Results show that the new method have centimeter-level accuracy.In the last part of this paper,real GPS signal are received and ionospheric delay is calculated and compared with results calculated using Klobuchar model.