A quick A-BDS location method based on characteristics of GEO satellite and ridge estimate

Abstract

The calculation of traditional A-GPS time-free positioning method will be very complex without the approximate position. But hybrid constellation was adopted by BeiDou Navigation Satellite System (BDS). And the GEO satellite of BDS has high speed of NAV data rate. So a fast positioning method for BDS receiver based on characteristics of GEO satellite and ridge estimate was proposed in this paper. First, an approximate position was got by using ridge estimate with GEO constellation. The ridge estimation can solve problem of coefficient matrix ill-conditioned. Then the signal transmission time of MEO/IGSO satellite was restored with the approximate position. A simulation environment was built by using BDS broadcast ephemeris information. The white noise with 6 m standard deviation was added to pseudoranges. The success rate of the quick location method is big than 99.65 % in China surrounding area. And about 80 % of China surrounding area can 100 % guarantee to restore a complete satellite signal emission time and obtain an accurate position.