BDS Pseudorange Augmentation Positioning Based on Carrier Smoothing Pseudorange

Objectives Pseudorange observations have the advantages of simple positioning mode and high real-time performance, but the positioning accuracy is difficult to be further improved due to the influence of the noise. Carrier phase smoothing pseudorange is the main means to improve the positioning accuracy of pseudorange.

Methods The method of BeiDou satellite navigation system (BDS) pseudorange augmentation positioning based on carrier smoothing pseudorange is proposed in the article, which uses the reference stations around the user station to generate error augmentation information to reduce user errors. At the same time, the smoothing pseudorange observations are used to generate error augmentation information. The smoothed error augmentation information does not change the error characteristics, and is compatible with the positioning model of different frequency observations of the users. The users can freely choose the positioning mode according to needs.

Results The results show that the residuals after smoothing are better than before, and the U direction is improved by 46% when a single station is smoothed. The positioning accuracies in N,E,U three directions are improved by 16%, 31%, and 53% at three frequencies. The accuracy of the U direction is improved significantly by various schemes.

Conclusions The smoothed error augmentation information is compatible with the user's single-frequency, dual-frequency, and multi-frequency smoothing and unsmoothing positioning. The smoothing of the user's observation can also further improve the positioning accuracy.