Research of RDSS Passive Positioning Based on Differential Virtual Pseudo Range

BD-1 passive positioning technology uses three GEO satellites and the earth reference surface to form observation equations. The timing reference is changed from satellite-based atomic clock to ground-based atomic clock, which assures higher pseudo range accuracy. In contrast, the pseudo range accuracy is limited by longer propagation path and delay of satellite transponder. This paper introduces the differential positioning concept into BD-1 passive positioning. The pseudo ranges are subtracted from a chosen satellite pseudo range and the equivalent differential pseudo range equations are derived. The equivalent differential pseudo range is independent with local time, so the clock error, hardware delay, atmosphere error, and noise can be eliminated. The simulation result shows that the differential technology can effectively improve the accuracy of the BD-1 passive positioning technology.