Abstract: At present, BDS broadcasts a variety of ionospheric model parameters, which causes the following confusion when users use it:①Different satellites may broadcast the same ionospheric model with different values in the same interval. ②The klobuchar model broadcast respectively by BDS-2 and BDS-3 are quite different. ③How to select the proper model from the three types of ionospheric model (BDS-2 Klobuchar、BDS-3 Klobuchar、BDGIM) that can be received at the same time. To propose a solution overcoming current shortcoming, this paper firstly proposes the maximum voting strategy to reasonably combine the parameters of the ionosphere models in the same calendar but with different values. Then, based on the ionosphere products of IGS analysis center, the accuracy of three BeiDou ionosphere model is analyzed and compared. Finally, the validation analysis is carried out based on the user equivalent range error(UERE). The results show that although the model values of BDS-2 Klobuchar and BDS-3 Klobuchar are quite different, the accuracy of the model is very close. Besides, the accuracy of BGDIM model is the highest, with 10% improvement compared with BDS-k8 model in the middle and low latitude area, and 61% improvement in the polar regions.

Key words: BDS-2 Klobuchar, BDS-3 Klobuchar, BDGIM, broadcast ionosphere model, UERE