Generation of DFMC SBAS Corrections Using MADOCA Precise Products

Abstract

Satellite Based Augmentation Systems (SBAS) are essential for safe GNSS-based navigation in civil aviation because they provide augmentation information to assure the integrity of navigation solutions for aircraft. In current SBAS standards, ionospheric delay correction is one of the main factors limiting augmentation performance. Dual-Frequency Multi-Constellation SBAS (DFMC SBAS), the next-generation SBAS standard, is expected to mitigate this limitation by enabling users to remove ionospheric delay accurately using dual-frequency observations. As the impact of ionospheric delay is reduced, the relative importance of satellite orbit and clock correction performance increases. Therefore, improving orbit and clock corrections is important for further enhancing DFMC SBAS, and the introduction of precise orbit determination is considered effective for this purpose. This study aims to simulate the correction performance of DFMC SBAS when precise orbit determination is introduced. To this end, a method for generating DFMC SBAS corrections using MADOCA precise products is presented, and the accuracy of the generated satellite orbit and clock corrections and the positioning performance are evaluated. The results confirm that DFMC SBAS corrections can be successfully generated and applied using MADOCA precise products, and that favorable satellite orbit and clock correction accuracy as well as favorable positioning performance can be obtained at three evaluation sites in Japan. These results demonstrate that introducing precise orbit determination is effective for improving satellite orbit and clock correction performance in DFMC SBAS.