A modified algorithm of combined GPS/GLONASS precise point positioning (GG-PPP) was developed by decreasing the number of unknowns to be estimated so that accurate position solutions can be achieved in the case of l...A modified algorithm of combined GPS/GLONASS precise point positioning (GG-PPP) was developed by decreasing the number of unknowns to be estimated so that accurate position solutions can be achieved in the case of less number of visible satellites. The system time difference between GPS and GLONASS (STDGG) and zenith tropospheric delay (ZTD) values were firstly estimated in an open sky condition using the traditional GG-PPP algorithm. Then, they were used as a priori known values in the modified algorithm instead of estimating them as unknowns. The proposed algorithm was tested using observations collected at BJFS station in a simulated open-pit mine environment. The results show that the position filter converges much faster to a stable value in all three coordinate components using the modified algorithm than using the traditional algorithm. The modified algorithm achieves higher positioning accuracy as well. The accuracy improvement in the horizontal direction and vertical direction reaches 69% and 95% at a satellite elevation mask angle of 50°, respectively.展开更多
Combined GPS/GLONASS can increase the accuracy and reliability of positioning especially in some applications with many impediments.Due to the atmosphere delay,the commonly used methods for processing short distance b...Combined GPS/GLONASS can increase the accuracy and reliability of positioning especially in some applications with many impediments.Due to the atmosphere delay,the commonly used methods for processing short distance baselines can not be implemented in long distance baselines.In this paper,a new data processing strategy for long distance baselines is proposed,which uses the properties of some combination observables of combined GPS/GLONASS and distance baselines may come to the order of 10 -8 and combined GPS/GLONASS improves the accuracy over that of GPS_only positioning,which brings benefit to crust deformation monitoring and research on geodynamics.展开更多
To obtain the GLONASS satellite position at an epoch other than reference time,the satellite’s equation of motion has to be integrated with broadcasting ephemerides.The iterative detecting and repairing method of cyc...To obtain the GLONASS satellite position at an epoch other than reference time,the satellite’s equation of motion has to be integrated with broadcasting ephemerides.The iterative detecting and repairing method of cycle slips based on triple difference residuals for combined GPS/GLONASS positioning and the iterative ambiguity resolution approach suitable for combined post processing positioning are discussed systematically.Experiments show that millimeter accuracy can be achieved in short baselines with a few hours’ dual frequency or even single frequency GPS/GLONASS carrier phase observations,and the precision of dual frequency observations is distinctly higher than that of single frequency observations.展开更多
随着中国BeiDou系统与欧盟Galileo系统的出现以及俄罗斯GLONASS系统的恢复完善,过去单一的GPS导航卫星系统时代已经逐步过渡为多系统并存且相互兼容的全球性卫星导航系统(multi-constellation global navigation satellite systems,mul...随着中国BeiDou系统与欧盟Galileo系统的出现以及俄罗斯GLONASS系统的恢复完善,过去单一的GPS导航卫星系统时代已经逐步过渡为多系统并存且相互兼容的全球性卫星导航系统(multi-constellation global navigation satellite systems,multi-GNSS)时代,多系统GNSS融合精密定位将成为未来GNSS精密定位技术的发展趋势。本文采用GPS、GLONASS、BeiDou、Galileo 4大卫星导航定位系统融合的精密单点定位(precise point positioning,PPP)实测数据,初步研究并分析了4系统融合PPP的定位性能。试验结果表明:在单系统观测几何构型不理想的区域,多系统融合能显著提高PPP的定位精度和收敛速度。4大系统融合的PPP收敛速度相对于单GNSS可提高30%~50%,定位精度可提高10%~30%,特别是对高程方向的贡献更为明显。此外,在卫星截止高度角大于30°的观测环境下,单系统由于可见卫星数不足导致无法连续定位,而多系统融合仍然可以获得PPP定位结果,尤其是水平方向具有较高的定位精度。这对于山区、城市以及遮挡严重的区域具有非常重要的应用价值。展开更多
基金Project(41004011)supported by the National Natural Science Foundation of ChinaProject(2014M550425)supported by the China Postdoctoral Science Foundation
文摘A modified algorithm of combined GPS/GLONASS precise point positioning (GG-PPP) was developed by decreasing the number of unknowns to be estimated so that accurate position solutions can be achieved in the case of less number of visible satellites. The system time difference between GPS and GLONASS (STDGG) and zenith tropospheric delay (ZTD) values were firstly estimated in an open sky condition using the traditional GG-PPP algorithm. Then, they were used as a priori known values in the modified algorithm instead of estimating them as unknowns. The proposed algorithm was tested using observations collected at BJFS station in a simulated open-pit mine environment. The results show that the position filter converges much faster to a stable value in all three coordinate components using the modified algorithm than using the traditional algorithm. The modified algorithm achieves higher positioning accuracy as well. The accuracy improvement in the horizontal direction and vertical direction reaches 69% and 95% at a satellite elevation mask angle of 50°, respectively.
文摘Combined GPS/GLONASS can increase the accuracy and reliability of positioning especially in some applications with many impediments.Due to the atmosphere delay,the commonly used methods for processing short distance baselines can not be implemented in long distance baselines.In this paper,a new data processing strategy for long distance baselines is proposed,which uses the properties of some combination observables of combined GPS/GLONASS and distance baselines may come to the order of 10 -8 and combined GPS/GLONASS improves the accuracy over that of GPS_only positioning,which brings benefit to crust deformation monitoring and research on geodynamics.
文摘To obtain the GLONASS satellite position at an epoch other than reference time,the satellite’s equation of motion has to be integrated with broadcasting ephemerides.The iterative detecting and repairing method of cycle slips based on triple difference residuals for combined GPS/GLONASS positioning and the iterative ambiguity resolution approach suitable for combined post processing positioning are discussed systematically.Experiments show that millimeter accuracy can be achieved in short baselines with a few hours’ dual frequency or even single frequency GPS/GLONASS carrier phase observations,and the precision of dual frequency observations is distinctly higher than that of single frequency observations.
文摘随着中国BeiDou系统与欧盟Galileo系统的出现以及俄罗斯GLONASS系统的恢复完善,过去单一的GPS导航卫星系统时代已经逐步过渡为多系统并存且相互兼容的全球性卫星导航系统(multi-constellation global navigation satellite systems,multi-GNSS)时代,多系统GNSS融合精密定位将成为未来GNSS精密定位技术的发展趋势。本文采用GPS、GLONASS、BeiDou、Galileo 4大卫星导航定位系统融合的精密单点定位(precise point positioning,PPP)实测数据,初步研究并分析了4系统融合PPP的定位性能。试验结果表明:在单系统观测几何构型不理想的区域,多系统融合能显著提高PPP的定位精度和收敛速度。4大系统融合的PPP收敛速度相对于单GNSS可提高30%~50%,定位精度可提高10%~30%,特别是对高程方向的贡献更为明显。此外,在卫星截止高度角大于30°的观测环境下,单系统由于可见卫星数不足导致无法连续定位,而多系统融合仍然可以获得PPP定位结果,尤其是水平方向具有较高的定位精度。这对于山区、城市以及遮挡严重的区域具有非常重要的应用价值。