Analysis on the integrity simulation of beidou dual-frequency satellite-based augmentation system

With the continuous development of GNSS applications, in order to satisfy high precision, high integrity demands for different users, especially aviation users, many countries are striving to develop Satellite-Based Augmentation Systems (SBAS). The BeiDou augmentation system is developed based on the BDS. To take full advantage of increasing satellite navigation systems, SBAS is gradually designed from single frequency to dual frequency, which is an important research issue of Satellite Based Augmentation System Interoperability Working Group. Based on the characteristics of dual-frequency SBAS (DF SBAS)system, the connotation of DF SBAS integrity is summarized, and the structure of BeiDou dual-frequency SBAS system is analyzed with the development plan of BDS. Aimed at the problem that SBAS integrity parameters are relatively conservative, a dual-frequency SBAS integrity optimization algorithm is proposed to optimize the SBAS weight matrix. The SBAS Simulator software is used to validate the integrity availability of BeiDou dual-frequency SBAS system in China and the surrounding areas. The results show that the SBAS algorithm can effectively reduce the HPL and VPL value, and improve the system availability.