The influence of improper stochastic modeling of Beidou pseudoranges on system reliability

Stochastic models are important in Global Navigation Satellite System (GNSS) estimation problems, not only for parameter estimation, or precision assessment, but also for deriving system reliability and integrity measures. China's Beidou GNSS (BDS) has received considerable research attention, however it has mainly focused on parameter estimation challenges. In this paper the influences of the BDS measurement stochastic model on the internal reliability index - minimal detectable bias (MDB), the separability index - correlation coefficient, and the integrity index - vertical protection level (VPL), for each satellite are analyzed and algebraic formulas derived for carrying out the calculations. The MDBs, correlation coefficients, and VPL values for different GEO, IGSO and MEO satellites indicate different patterns within the test area. It is shown that BDS has better constellation visibility in the East Asian area, and accordingly confirms optimal positioning and reliability performance within this region.