Combining the observation data from five Multi-GNSS Experiment(MGEX)stations with the precise orbit and clock products from Global Positioning System(GPS)and BeiDou Navigation Satellite System(BDS),we studied the mode...Combining the observation data from five Multi-GNSS Experiment(MGEX)stations with the precise orbit and clock products from Global Positioning System(GPS)and BeiDou Navigation Satellite System(BDS),we studied the model of combined GPS/BDS precise point positioning,and then analyzed the convergence speed and short-time(6 h)positioning accuracy.The calculation results show that in static positioning,the average convergence time of GPS is about 50 min,and its horizontal accuracy is better than 2 cm while the vertical accuracy is better than 4 cm.The convergence speed of combined GPS/BDS is about 40 min,and its positioning accuracy is close to that of GPS.In kinematic positioning,the average convergence time of GPS is about 72 min,and its horizontal accuracy is better than 5 cm while the vertical accuracy is better than 12 cm.The average convergence time of GPS/BDS is about 57 min,and its horizontal accuracy is better than 3 cm while the vertical accuracy is better than 9 cm.Combined GPS/BDS has significantly improved the convergence speed,and its positioning accuracy is slightly than that of GPS.展开更多
整周模糊度固定是精密单点定位(precise point positioning,PPP)实现快速厘米级定位的关键。传统双频无电离层组合窄巷模糊度固定存在组合观测噪声放大而导致固定成功率低的问题,进而影响PPP的收敛时间。为此,该文联合北斗全球卫星导航...整周模糊度固定是精密单点定位(precise point positioning,PPP)实现快速厘米级定位的关键。传统双频无电离层组合窄巷模糊度固定存在组合观测噪声放大而导致固定成功率低的问题,进而影响PPP的收敛时间。为此,该文联合北斗全球卫星导航系统(BeiDou Global Navigation Satellite System,BDS-3)播发的新频点,提出了一种兼顾组合噪声抑制的四频无电离层快速PPP模糊度固定方法,并结合自制教学仪器设计了实验流程。该方法利用搭建的基准站和试验车构建静态和动态的实验场景,测试结果表明相比传统四频方法所提方法,的模糊度固定成功率在静态和动态场景下分别提升了8.4%和15.8%,显著提成了PPP的收敛时间。该文对多频PPP的模糊度固定流程进行了详细的说明,有助于学生更好地理解多频观测量组合对加快模糊度固定的优势及误差抑制的应对措施。展开更多
In order to solve the problem of landslide hazard to people in our country, this paper takes a landslide in Shanxi province as an example, based on BDS/GPS dual-frequency ionosphere-free combination Precise Point Posi...In order to solve the problem of landslide hazard to people in our country, this paper takes a landslide in Shanxi province as an example, based on BDS/GPS dual-frequency ionosphere-free combination Precise Point Positioning (PPP), and analyzes the reliability of BDS/GPS dual-frequency ionosphere-free combination PPP in landslide deformation monitoring from convergence time and three-dimensional deformation of landslide. The research results show that the convergence of BDS/GPS dual-frequency precise point positioning can achieve centimeter-level accuracy in the landslide environment. The convergence data can accurately measure the horizontal and vertical changes of the landslide, and can provide a strong basis and support for the disaster prevention of the landslide.展开更多
GNSS精密单点定位(precise point positioning,PPP)技术是一类基于卫星信号,实现全球精密定位的方法,其工作原理为采用一台GNSS接收机的双频码和载波相位观测值,利用精密轨道和精密钟差产品,同时应用精细化的误差修正数学模型,进行单站...GNSS精密单点定位(precise point positioning,PPP)技术是一类基于卫星信号,实现全球精密定位的方法,其工作原理为采用一台GNSS接收机的双频码和载波相位观测值,利用精密轨道和精密钟差产品,同时应用精细化的误差修正数学模型,进行单站绝对定位.PPP不依赖地面基准站,它的出现改变了以往只有载波相位双差观测模型才能达到高精度定位的情况,是GNSS定位技术中继RTK和网络RTK技术之后的又一次技术革命.本文主要介绍了PPP中的双频消电离层组合的定位方程组、误差修正数学模型以及参数估计的最小二乘方法,并通过算例展示了PPP的有效性.展开更多
During the period when a GPS satellite,the Earth and the Sun are approximately collinear,the phenomenon of eclipsing the satellite occurs,when the satellite yaw attitude deviates from its nominal case,i.e. the body X-...During the period when a GPS satellite,the Earth and the Sun are approximately collinear,the phenomenon of eclipsing the satellite occurs,when the satellite yaw attitude deviates from its nominal case,i.e. the body X-axis cannot point towards the Sun for Block II&IIA or away from it for Block IIR satellites. The yaw attitude of the eclipsing satellites has a significant influence on both the satellite clock estimation at each International GNSS Service (IGS) Analysis Center (AC) and for users of the precise point positioning (PPP) implementations. It is known that,during the eclipsing periods,inconsistent yaw attitude models among the ACs will contribute to the errors of the IGS combined clock products. As for the PPP user,the influence of the eclipsing satellite is two-fold. First,as the satellite clocks are always kept fixed during PPP implementation,the above-mentioned problematic IGS clocks will inevitably be passed on to the PPP estimates. Second,the improper yaw attitude modeling of the eclipsing satellite will cause a correction bias exceeding 1 dm for the two kinds of attitude-related systematic errors,namely the phase wind-up and satellite antenna phase center offset,which will further deteriorate the accuracy of the PPP solutions. A yaw attitude model is introduced in this paper with the aim of improving the reliability of PPP solutions during the satellite eclipsing period.展开更多
This paper introduces the background of producing precise point positioing, the observation equation of static precise point positioning, the handling methods of each parameter in the equation, the correction which mu...This paper introduces the background of producing precise point positioing, the observation equation of static precise point positioning, the handling methods of each parameter in the equation, the correction which must be taken iinto account, and the data processing method. And this paper also presents the characteristics and applications of kinetic precise point positioning.展开更多
基金supported by Director Foundation of the Institute of Seismology,China Earthquake Administration(6110).
文摘Combining the observation data from five Multi-GNSS Experiment(MGEX)stations with the precise orbit and clock products from Global Positioning System(GPS)and BeiDou Navigation Satellite System(BDS),we studied the model of combined GPS/BDS precise point positioning,and then analyzed the convergence speed and short-time(6 h)positioning accuracy.The calculation results show that in static positioning,the average convergence time of GPS is about 50 min,and its horizontal accuracy is better than 2 cm while the vertical accuracy is better than 4 cm.The convergence speed of combined GPS/BDS is about 40 min,and its positioning accuracy is close to that of GPS.In kinematic positioning,the average convergence time of GPS is about 72 min,and its horizontal accuracy is better than 5 cm while the vertical accuracy is better than 12 cm.The average convergence time of GPS/BDS is about 57 min,and its horizontal accuracy is better than 3 cm while the vertical accuracy is better than 9 cm.Combined GPS/BDS has significantly improved the convergence speed,and its positioning accuracy is slightly than that of GPS.
文摘整周模糊度固定是精密单点定位(precise point positioning,PPP)实现快速厘米级定位的关键。传统双频无电离层组合窄巷模糊度固定存在组合观测噪声放大而导致固定成功率低的问题,进而影响PPP的收敛时间。为此,该文联合北斗全球卫星导航系统(BeiDou Global Navigation Satellite System,BDS-3)播发的新频点,提出了一种兼顾组合噪声抑制的四频无电离层快速PPP模糊度固定方法,并结合自制教学仪器设计了实验流程。该方法利用搭建的基准站和试验车构建静态和动态的实验场景,测试结果表明相比传统四频方法所提方法,的模糊度固定成功率在静态和动态场景下分别提升了8.4%和15.8%,显著提成了PPP的收敛时间。该文对多频PPP的模糊度固定流程进行了详细的说明,有助于学生更好地理解多频观测量组合对加快模糊度固定的优势及误差抑制的应对措施。
文摘In order to solve the problem of landslide hazard to people in our country, this paper takes a landslide in Shanxi province as an example, based on BDS/GPS dual-frequency ionosphere-free combination Precise Point Positioning (PPP), and analyzes the reliability of BDS/GPS dual-frequency ionosphere-free combination PPP in landslide deformation monitoring from convergence time and three-dimensional deformation of landslide. The research results show that the convergence of BDS/GPS dual-frequency precise point positioning can achieve centimeter-level accuracy in the landslide environment. The convergence data can accurately measure the horizontal and vertical changes of the landslide, and can provide a strong basis and support for the disaster prevention of the landslide.
文摘GNSS精密单点定位(precise point positioning,PPP)技术是一类基于卫星信号,实现全球精密定位的方法,其工作原理为采用一台GNSS接收机的双频码和载波相位观测值,利用精密轨道和精密钟差产品,同时应用精细化的误差修正数学模型,进行单站绝对定位.PPP不依赖地面基准站,它的出现改变了以往只有载波相位双差观测模型才能达到高精度定位的情况,是GNSS定位技术中继RTK和网络RTK技术之后的又一次技术革命.本文主要介绍了PPP中的双频消电离层组合的定位方程组、误差修正数学模型以及参数估计的最小二乘方法,并通过算例展示了PPP的有效性.
基金supported by the National Science Foundation for Distinguished Young Scholars (40625013)the National Natural Science Foundation of China (40890160 and 40874009)the National High-Tech Research and Development Program of China (2007AA12Z311,2007A-A12-Z305)
文摘During the period when a GPS satellite,the Earth and the Sun are approximately collinear,the phenomenon of eclipsing the satellite occurs,when the satellite yaw attitude deviates from its nominal case,i.e. the body X-axis cannot point towards the Sun for Block II&IIA or away from it for Block IIR satellites. The yaw attitude of the eclipsing satellites has a significant influence on both the satellite clock estimation at each International GNSS Service (IGS) Analysis Center (AC) and for users of the precise point positioning (PPP) implementations. It is known that,during the eclipsing periods,inconsistent yaw attitude models among the ACs will contribute to the errors of the IGS combined clock products. As for the PPP user,the influence of the eclipsing satellite is two-fold. First,as the satellite clocks are always kept fixed during PPP implementation,the above-mentioned problematic IGS clocks will inevitably be passed on to the PPP estimates. Second,the improper yaw attitude modeling of the eclipsing satellite will cause a correction bias exceeding 1 dm for the two kinds of attitude-related systematic errors,namely the phase wind-up and satellite antenna phase center offset,which will further deteriorate the accuracy of the PPP solutions. A yaw attitude model is introduced in this paper with the aim of improving the reliability of PPP solutions during the satellite eclipsing period.
文摘This paper introduces the background of producing precise point positioing, the observation equation of static precise point positioning, the handling methods of each parameter in the equation, the correction which must be taken iinto account, and the data processing method. And this paper also presents the characteristics and applications of kinetic precise point positioning.
