Analysis of ionospheric delay correction methods for BeiDou navigation satellite system

Satellite navigation signal is affected by ionospheric delay during transmission and it is modified by different models. The residual errors are different and it leads to the influence on timing and positioning accuracy of satellite navigation system. In this paper, Klobuchar model, grid model and dual-frequency correction method are introduced respectively. The timing errors of BeiDou satellites are calculated by using these three methods. And then according to their timing errors, correction accuracy of these ionospheric delay correction methods are analyzed and compared. It is shown that the correction accuracy of dual-frequency correction method is highest which is followed by grid model and Klobuchar model for BeiDou users. The correction accuracy of grid model is higher which is followed by Klobuchar model.