LEO constellation-augmented SBAS and performance simulation analysis

Satellite-Based Augmentation System (SBAS) relying on ground monitoring networks can only provide regional services in their own countries or regions. DFMC can expand service coverage and improve service quality, but it still needs the support of the ground monitoring network. Equipped with a spaceborne receiver, LEO has a unique advantage in space-based monitoring, which is expected to expand the service coverage and improve the service performance of SBAS. A global integrity monitoring method of SBAS combining LEO satellites and regional ground station data is proposed. Based on simulation data, the improvement effect of this method compared with that of relying solely on ground station data is verified from the aspects of correction sequence, monitoring arc integrity, enhanced satellite number and coverage. The results of global user positioning accuracy, integrity and usability evaluation are also given. The results show that this method can effectively extend the service coverage of SBAS and improve its performance. On a global scale, the average horizontal positioning accuracy of users is better than 0.5m and the average vertical positioning accuracy is better than 1 m. The pseudo-range residual reduction reached 21%, and the availability met the requirements of APV-I. The addition of LEO can effectively expand the monitoring and service scope of BDSBAS and improve its performance.