A Method of Determining the Weight Matrix for BDS DCB Resolution

The differential code bias( DCB) in global navigation satellite system( GNSS) satellites should be precisely determined using real ground GNSS data when designing certain applications, such as precise positioning,navigation and timing. This paper analyzed the relationship between satellite elevation angle with difference SNR( signal to noise ratio) of BDS( Bei Dou Satellite Navigation System) different orbital satellite. The experimental results showed that the SNR difference of IGSO satellite was smaller and more stable, much better than other satellites; the change of GEO satellite SNR difference( DSNR) was small, but the absolute value was large; MEO satellite SNR difference changed frequently and big. A new algorithm to get the BDS observation weight was introduced by considering the distance between the satellite and the Earth and SNR difference. The results indicated that the new weight algorithm improved the accuracy and enhanced the stabilities of DCB12 and DCB13, which improved GEO satellites 1% ~ 15% and 9% ~ 16%, IGSO satellites 4. 5% ~ 16% and 8% ~ 9%, MEO satellites20% ~ 22% and 27% ~ 28%.