BDS Availability Calculation and Visual Display Based on Monitoring Data

GNSS is the main source of PNT information for maritime ship users. Its availability is related to the safety of ship navigation, and is also an important state that the maritime management department urgently needs to evaluate and monitor. However, the large amount of monitoring data of Satellite navigation brings huge challenges to the analysis and evaluation of its global availability. This paper uses BDS monitoring data as the data source, and first introduces the specific parameters and format characteristics of BDS's broadcast ephemeris data. Then calculate the real-time position of the satellite based on the ephemeris data. Finally, based on grid theory and visualization techniques, divide the grid points, calculate the number of visible satellites and corresponding PDOP values for each grid point, and thus calculate the navigation availability of that grid point. This paper realizes the visualization display of real-time satellite positions, the number of visible satellites at each grid point and the availability data in a global scale on the MATLAB platform. It can also zoom in on local areas and display visually and clearly the availability of BDS navigation services, providing an important reference for maritime management departments to conduct maritime navigation safety assessment and assist decision-making.