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Global instantaneous centimeter-level precise point positioning with multi-constellation and multi-frequency cascading ambiguity resolution

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Global instantaneous centimeter-level precise point position...

第十四届中国卫星导航年会

作者： lizhong qu Luping Wang Haoyu Wang Wei Jiang Yiwei Du School of Geomatics and Urban Spatial Informatics Beijing University of Civil Engineering and Architecture

With the rapid development of multi-frequency Global Navigation Satellite System(GNSS), more satellites transmitting the multi-frequency signals can contribute the performance improvement of global instantaneous or single-epoch precise point positioning(PPP). More wide-lane(WL) ambiguities can be fixed instantaneously to enhance the accuracy of the instant narrow-lane(NL) ambiguities even without accurate atmosphere corrections. Therefore,global single-epoch NL AR may be possible and global instantaneous centimeter-level PPP may be reached. To achieve the goal, the uncombined PPP cascading WL/NL AR method(PPP-CAR) was extended to the multiconstellation and multi-frequency signals. The GPS, Galileo, and BDS-3 allfrequency signals were used to investigate the global single-epoch PPP performance with the global public stations based on the proposed method. The test results indicated that attributed to the contribution of additional frequency observations, the instant positioning accuracy of the PPP-CAR improved substantially. On a global scale, the instant positioning accuracy of the horizontal and up components improved from about 20 and 60 cm, respectively,for the dual-frequency PPP-CAR to about 6 and 20 cm, respectively, for the triple-frequency, quad-frequency, and five-frequency PPP-CARs. The global horizontal instantaneous centimeter-level PPP was achieved. However, with increasing frequencies, the fixing rates of NL ambiguities slightly decreased,demonstrating that more reliable NL AR was obtained, attributed to more WL ambiguities being fixed instantaneously. These results are very encouraging because better positioning accuracy is expected for global autonomous driving cars as long as integrating the multi-constellation and multi-frequency signals with other sensors, such as inertial sensors.

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Initial Research on Comparison of PPP-inferred GPS- and BDS-PWV in China Region

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Initial Research on Comparison of PPP-inferred GPS- and BDS-...

第五届中国卫星导航学术年会

作者： Wenwen Li Min Li lizhong qu Xing Su Qile Zhao School of Geodesy and Geomatics Wuhan University Research Center of GNSS Wuhan University

Due to the special constellation design with GEO, IGSO and MEO, the BeiDou System (BDS) now is available to provide a good coverage over the China region. This makes it possible to study the precipitable water vapor (PWV) inversion with only BeiDou observations using the precise point positioning (PPP) method. This paper selected 5 stations among the BETS (BeiDou Experiment Tracking Stations) network with GPS/BDS dual‐mode dual‐frequency data for the research. By the PPP approach, the zenith tropospheric delay (ZTD) was estimated at each station using only BDS or GPS observations respectively. And then the PWV was obtained by a conversion factor and the zenith wet delay retrieved from the estimated ZTD. The results shows that due to the bias of 10mm existing between the BDS‐ and GPS‐derived ZTD, the inferred BDS‐PWV and GPS‐PWV is biased about 0.1mm. And the final mean bias and STD of BDS‐ and GPS‐PWV difference of all 5 stations is 0.78mm and 1.73mm. It is concluded that the PWV inferred from BDS can reach similar precision comparing to the GPS‐PWV in the China region. 1

关键词： BeiDou System Precipitable Water Vapor GPS Tropospheric Delay PANDA

Precise point positioning using combined Beidou and GPS observations

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Precise point positioning using combined Beidou and GPS obse...

第四届中国卫星导航学术年会

作者： lizhong qu Qile Zhao Min Li Jing Guo Xing Su Jingnan Liu GNSS Center Wuhan University

By the end of year 2012, China has launched 16 Beidou-2/Compass-2 navigation satellites that include 6 GEO, 5IGSO and 5 MEO. Initial navigation and precise pointing services ability has formed in the Asian-Pacific regions. In order to know the navigation and positioning performance of Beidou-2 system, Wuhan University has built up a Beidou Experimental Tracking Stations over the world and extents the PANDA software to determine the orbits of Beidou satellites, that supplies the Beidou satellites’ precise orbit and satellite clock offset for the users needing high accuracy positioning services. This article uses the Beidou/GPS observations of the Beidou Experimental Tracking Stations to realize the Beidou and Beidou/GPS static and kinematic precise point positioning （PPP）. The result indicates that the precision of Beidou static and kinematic PPP reaches centimeter level, the precision of combined Beidou/GPS static and kinematic PPP improves than that of both only-Beidou and only-GPS and the convergence time is less than that of both only-Beidou and only-GPS.

关键词： Beidou satellite navigation system· Beidou Experimental Tracking Stations· PNADA · Beidou/GPS ·Precise point positioning(PPP)

COMPASS Three Carrier Ambiguity Resolution

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COMPASS Three Carrier Ambiguity Resolution

第四届中国卫星导航学术年会

作者： DAI Zhiqiang ZHAO Qile HU Zhigang SU Xing qu lizhong GUO Qiang School of Geodesy and Geomatics Wuhan University National Engineering Research Center for Satellite Navigation System Wuhan University

The new generation of global navigation satellite systems （GNSSs） introduce a third （or more） carrier, which benefit ambiguity resolution （AR）. TCAR （Three-Carrier Ambiguity Resolution） and CIR （Cascaded Integer Resolution） are the typical three-carrier ambiguity resolution methods, which are biased by the residual ionospheric delay. Based on the COMPASS three-carrier observables, this contribution investigate the TCAR/CIR methods, and accommodated them to the middle and long baseline by introducing some modifications. The modified TCAR/CIR methods contributes to the second and third steps of the old methods, which reduce the error in the second step slightly from 0.547 to 0.478, and that in the third step sharply form 17.913 to 5.062.

关键词： GNSS TCAR CIR COMPASS/BeiDou-2

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多模GNSS精密卫星钟差估计与分析

武汉大学学报（信息科学版） 2018年第1期43卷 107-111页

作者：屈利忠杜明义王坚赵齐乐郭靖北京建筑大学测绘与城市空间信息学院北京102600 北京建筑大学建筑遗产精细重构与健康监测北京市重点实验室北京102600 武汉大学卫星导航定位技术研究中心湖北武汉430079

对基于历元间差分相位和非差伪距观测值的混合差分卫星钟差估计方法进行了改进,实现了多模全球导航卫星系统（Global Navigation Satellite System,GNSS）卫星钟差联合快速估计。选择了全球分布的50个跟踪站进行实验,对卫星钟差精度进... 详细信息

对基于历元间差分相位和非差伪距观测值的混合差分卫星钟差估计方法进行了改进,实现了多模全球导航卫星系统（Global Navigation Satellite System,GNSS）卫星钟差联合快速估计。选择了全球分布的50个跟踪站进行实验,对卫星钟差精度进行了分析和精密单点定位（Precise Point Positioning,PPP）验证。结果表明：多模卫星钟差与武汉大学提供的最终精密卫星钟差互差优于0.2ns,精密单点定位结果与武汉大学发布的最终精密卫星轨道和钟差产品的定位精度相当。

关键词：多模GNSS 历元间差分相位和非差伪距观测值精密卫星钟差估计 PPP

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实时GNSS数据流管理平台的实现及应用

测绘通报 2016年第4期 92-95页

作者：蒋科材屈利忠赵齐乐武汉大学卫星导航定位技术研究中心湖北武汉430079

随着互联网技术的发展,利用互联网将观测站的实时GNSS数据高速传输给数据处理中心,可以打破GNSS数据事后处理的传统模式,从而实现GNSS数据的实时处理。对于数据处理中心而言,具备实时GNSS数据流管理功能的软件平台就显得尤为重要。本文... 详细信息

随着互联网技术的发展,利用互联网将观测站的实时GNSS数据高速传输给数据处理中心,可以打破GNSS数据事后处理的传统模式,从而实现GNSS数据的实时处理。对于数据处理中心而言,具备实时GNSS数据流管理功能的软件平台就显得尤为重要。本文主要对自主实现的实时GNSS数据流管理平台软件的实现及应用进行了介绍。该软件采用C/S框架设计,实现后端服务与前端用户界面相分离的效果,可通过网络与观测站建立连接来获取实时GNSS数据流,支持TCP/IP通信协议及NTRIP通信协议,支持解码RTCM3.X、BINEX等多种数据传输格式,能够汇聚分布在各地的观测站的GNSS数据,为后续的数据实时处理工作提供数据支撑,并在我国所发起的国际GNSS监测评估系统建设中得到应用。

关键词：实时GNSS数据流管理数据传输数据解码 C/S框架设计 NTRIP协议

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品牌价值网络结构模型及网络化传递研究

工业技术经济 2013年第4期32卷 9-15页

作者：唐玉生曲立中刘雪冰广西大学南宁530004

现实中品牌经营管理的统计数据表明,单一品牌为顾客创造的价值是有限的,且风险很大。关联企业以价值网络的方式相互协作,共同为顾客创造价值才是更优的模式选择。本文在文献梳理的基础上,以企业价值网络理论与品牌关系理论为背景,构建... 详细信息

现实中品牌经营管理的统计数据表明,单一品牌为顾客创造的价值是有限的,且风险很大。关联企业以价值网络的方式相互协作,共同为顾客创造价值才是更优的模式选择。本文在文献梳理的基础上,以企业价值网络理论与品牌关系理论为背景,构建并阐释了品牌价值网络结构模型及其内涵与策略体系;动态揭示了品牌价值的网络化传递的路径与影响因素。

关键词：品牌价值品牌价值网络品牌价值传递

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GNSS融合动态精密单点定位性能分析

大地测量与地球动力学 2016年第4期36卷 298-302页

作者：屈利忠赵齐乐郭靖许小龙武汉大学卫星导航定位技术研究中心武汉市珞喻路129号430079

基于武汉大学PANDA软件生成的GPS/GLONASS/BDS/Galileo四系统精密轨道和钟差产品,采用MGEX跟踪站多模观测数据进行试算,对GPS、GPS/BDS、GPS/GLONASS、GLONASS/BDS、GPS/GLONASS/BDS以及GPS/GLONASS/BDS/Galileo 7种模式的动态精密单点定位的精度和收敛性进行比较。结果表明:1)BDS动态PPP收敛速度较慢,收敛后精度能够达到cm级;2)GPS/BDS融合定位北方向分量精度不如GPS单系统定位,但东方向和高程方向分量收敛速度和定位精度都得到改善;GPS/GLONASS和GLONASS/BDS融合定位提高了东方向、北方向和高程方向分量的收敛速度和定位精度;3)GPS/GLONASS/BDS融合定位20min即可收敛,收敛后平面精度优于1cm,高程精度优于3cm;Galileo的引入对收敛速度和定位精度的改善不明显。

关键词：动态精密单点定位 GPS/GLONASS/BDS/Galileo 定位精度收敛速度

Research on Integrated Orbit Determination Combined Satellite-Ground and Inter-Satellite Observation Based on Helmert Method of Variance Components Estimate

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Research on Integrated Orbit Determination Combined Satellit...

第三届中国卫星导航学术年会

作者： SU Xing1, GENG Tao1, ZHAO Qile1, qu lizhong1, Li Xingkai11. Research Center of GNSS, Wuhan University, Wuhan, China

Because of the different precision of the satellite-ground and inter-satellite observations, how to correctly determine the weight of the two kinds of observations is still a key technique in integrated orbit determination. According to the ground stations and different kinds of the inter-satellite cross-link of the Chinese COMPASS satellite navigation system, the weight of the two kinds of observations was determined by the Helmert method of variance components estimate, and then the new weight was used in the integrated orbit determination. The results show that this method could reasonably determine the weight of satellite-ground and inter-satellite observations and improve the precision of integrated orbit determination. For the integrated orbit determination based on the Satellite-Ground and Inter-Satellite cross-link fixed antenna data, the orbit accuracies improve from 0.15m to 0.04m after use the Helmert estimation weight to replace the priori. And the result is 0.06m to 0.03m for the Satellite-Ground and Inter-Satellite cross-link UHF antenna data.

关键词： Helmert method of variance components estimate integrated orbit determination parameter estimation