精密单点定位(Precise Point Positioning,PPP)利用接收机收到的载波相位测量值进行定位,载波相位整周模糊度的固定影响着PPP的收敛速度和定位精度。采用B2a信号替代B2I信号,与B1I、B3I组成三频信号观测值组合,在此基础上对传统Boot-str...精密单点定位(Precise Point Positioning,PPP)利用接收机收到的载波相位测量值进行定位,载波相位整周模糊度的固定影响着PPP的收敛速度和定位精度。采用B2a信号替代B2I信号,与B1I、B3I组成三频信号观测值组合,在此基础上对传统Boot-strapping方法加以改进,提出了一种改进的三频模糊度解算方法。该方法采用了超宽巷-超宽巷-宽巷-窄巷的解算策略,通过比较选择波长较长、电离层延迟较小、测量噪声较小的三频观测值组合,分别用于解算超宽巷组合、宽巷组合和窄巷组合的模糊度。当电离层延迟无法忽略时,所提方法通过引入额外的伪距观测量来消除在解算组合模糊度的过程中出现的电离层参数和几何参数的影响。实验表明,所提方法与传统方法在完成一次模糊度解算的时间上相差无几,但是相比于传统方法,所提方法具有更高的模糊度解算成功率。展开更多
Currently,the BeiDou⁃3(BDS⁃3)precise point positioning(PPP)service(PPP⁃B2b)mostly employs the ionosphere⁃free(IF)combination model for precise timing,which tends to amplify the noise in observation values.To address t...Currently,the BeiDou⁃3(BDS⁃3)precise point positioning(PPP)service(PPP⁃B2b)mostly employs the ionosphere⁃free(IF)combination model for precise timing,which tends to amplify the noise in observation values.To address this issue,this paper proposes a real⁃time BDS⁃3 precise unidirectional timing model based on uncombined(UC)observations using the BDS⁃3 PPP⁃B2b service.This model resolves the challenge of the amplified observation noise inherent in the IF combination model.The experiment involved selecting eight global navigation satellite system(GNSS)observation stations within China and collecting continuous observation data for 15 d.A comparative analy⁃sis with the traditional dual⁃frequency IF combination PPP timing model showed that the BDS⁃3 UC PPP timing based on the BDS⁃3 PPP⁃B2b service can achieve a timing preci⁃sion of 0.5 ns.In addition,it was found that due to global positioning system(GPS)satellite clock products in the BDS⁃3 PPP⁃B2b service not being unified to the standard time,the GPS IF PPP timing method based on the BDS⁃3 PPP⁃B2b service is not recommended for precise timing.In summary,the BDS⁃3 UC PPP timing model proposed in this paper is suitable for precise timing,providing observa⁃tion values with smaller noise,and its timing accuracy is comparable to that of the BDS⁃3 IF PPP,with slightly better frequency stability.展开更多
文摘精密单点定位(Precise Point Positioning,PPP)利用接收机收到的载波相位测量值进行定位,载波相位整周模糊度的固定影响着PPP的收敛速度和定位精度。采用B2a信号替代B2I信号,与B1I、B3I组成三频信号观测值组合,在此基础上对传统Boot-strapping方法加以改进,提出了一种改进的三频模糊度解算方法。该方法采用了超宽巷-超宽巷-宽巷-窄巷的解算策略,通过比较选择波长较长、电离层延迟较小、测量噪声较小的三频观测值组合,分别用于解算超宽巷组合、宽巷组合和窄巷组合的模糊度。当电离层延迟无法忽略时,所提方法通过引入额外的伪距观测量来消除在解算组合模糊度的过程中出现的电离层参数和几何参数的影响。实验表明,所提方法与传统方法在完成一次模糊度解算的时间上相差无几,但是相比于传统方法,所提方法具有更高的模糊度解算成功率。
基金The Basic Science Center Project of the National Natural Science Foundation of China(No.42388102)the Jiangsu Province Natural Resources Science and Technology Project(No.JSZRKJ202404).
文摘Currently,the BeiDou⁃3(BDS⁃3)precise point positioning(PPP)service(PPP⁃B2b)mostly employs the ionosphere⁃free(IF)combination model for precise timing,which tends to amplify the noise in observation values.To address this issue,this paper proposes a real⁃time BDS⁃3 precise unidirectional timing model based on uncombined(UC)observations using the BDS⁃3 PPP⁃B2b service.This model resolves the challenge of the amplified observation noise inherent in the IF combination model.The experiment involved selecting eight global navigation satellite system(GNSS)observation stations within China and collecting continuous observation data for 15 d.A comparative analy⁃sis with the traditional dual⁃frequency IF combination PPP timing model showed that the BDS⁃3 UC PPP timing based on the BDS⁃3 PPP⁃B2b service can achieve a timing preci⁃sion of 0.5 ns.In addition,it was found that due to global positioning system(GPS)satellite clock products in the BDS⁃3 PPP⁃B2b service not being unified to the standard time,the GPS IF PPP timing method based on the BDS⁃3 PPP⁃B2b service is not recommended for precise timing.In summary,the BDS⁃3 UC PPP timing model proposed in this paper is suitable for precise timing,providing observa⁃tion values with smaller noise,and its timing accuracy is comparable to that of the BDS⁃3 IF PPP,with slightly better frequency stability.
