Comparative Analysis of Positioning Capability of Beidou and GPS in Maritime Islands

After the full deployment of the Beidou-3 global satellite navigation system constellation, the positioning service range has been expanded from the Asia-Pacific region to the whole world. At present, most of the research on the positioning capability of Beidou system is on the mainland, and there is still room for research on the positioning capability of islands at sea. In this paper, the data of four IGS tracking stations distributed in islands are selected and solved by Anubis software. The visualization of Beidou and GPS is analyzed in five aspects: satellite visible number, standard single point positioning error, DOP value, signal-to-noise ratio, and multi-path effect. The results show that: (1) In the Asia-Pacific region, the positioning accuracy of Beidou's maritime islands is better than 0.734 m, 0.724 m, and 2.115 m in the N, E, and U directions, respectively, which is basically equivalent to GPS. Whereas, it is roughly 3 m, 3 m and 6 m lower than GPS outside the Asia-Pacific region, and the average number of visible satellites of Beidou in ANMG station and SOLO station is 15 and 11 respectively, which presumably means that the satellite density of Beidou system in the Asia-Pacific region is higher. (2) The average values of signal-to-noise ratio and multipath error of C22, C23, C24 and C25 stars of BeiDou are 41.638 dBHz and 0.574 m, respectively, which are basically comparable to those of G01, G02, G03 and G04 stars of GPS. The work done in this paper enriches the research related to the maritime positioning of Beidou system and plays a role in the globalization process of Beidou.