Determination of Fast Corrections for Satellite-Based Augmentation System

Fast corrections are the vital parameters of satellite-based augmentation system, mitigating the rapidly changing errors of satellite clock. It is necessary to develop a feasible method to determine fast corrections because the rapidly changing errors of satellite clock badly affect the service performance. For such a purpose, a user equivalent range error-based method is proposed to determine fast corrections in this paper. Firstly, a generation process of satellite corrections is given for the control segment of satellite-based augmentation system. In this process, long-term corrections are generated first. Once the slowly varying errors of satellite ephemeris and clock are eliminated by long-term corrections, a user equivalent range error-based method is developed to solve fast corrections. Finally, the performance of the proposed method is analyzed in signal-in-space domain and position domain. Results demonstrate that compared with WAAS method, the accuracy of signal-in-space is improved by over 25.74% and the integrity bounding rate in pseudorange domain is improved by 4.23%.