Precise estimation of residual tropospheric delays using a regional GPS network for real-time kinematic applications   总被引：7，自引：0，他引：7  

J. Zhang  G. Lachapelle 《Journal of Geodesy》2001,75(5-6):255-266

 A new method called Trop_NetAdjust is described to predict in real time the residual tropospheric delays on the GPS carrier phase observables using the redundant measurements from a network of GPS reference stations. This method can not only enhance the effectiveness and reliability of real-time kinematic users within the network, but also provide a valid approach to tropospheric parameter variation forecasting. Trop_NetAdjust is theoretically based upon LS prediction criteria and enables the prediction of residual tropospheric delays remaining after a standard model has been applied to the raw GPS measurements. Two cases are analyzed, namely a first case when the delay is required for an existing satellite at a new point within the network and a second case when the delay is required for a new satellite. Field tests were conducted using data collected in a network of 11 reference stations covering a 400×600 km region in southern Norway. The results were analyzed in the measurement domain (ionospheric-free double-difference residuals) and showed improvements of 20 to 65% RMS errors using Trop_NetAdjust. The estimates of the Trop_NetAdjust prediction accuracy were also obtained using the covariance analysis method. The agreement was consistently better than 30% when compared with data from a real network. Received: 28 February 2000 / Accepted: 9 January 2001  相似文献   

我国卫星导航应用市场分析   总被引：2，自引：0，他引：2  

杨军  周儒欣 《全球定位系统》2003,28(5):45-49

分析了中国卫星导航定位产业特征，并用波特五力分析模型对卫星导航定位产业吸引力进行了分析，得出该产业是颇具吸引力的朝阳产业，该产业中的利益各方正处于从无序到有序的发展过程中的结论；指出了制约产业发展的三大问题和两大发展方向.  相似文献   

导航定位后处理信息管理系统     

胡家赋  薛玖红  汪徐宁 《现代测绘》2003,26(4):46-48

本文介绍了采用VC 语言开发的导航后处理系统，分析了其结构、功能特点、系统配置、操作方法及在海洋勘探中的应用。  相似文献   

NUMERICAL SIMULATION OF RIVER BED CHANGE AT SIMAO PORT     

LI Yitian  Professor  Wuhan University of Hydraulic  Electric Engineering  Wulhan    China HU Haiming Wuhan University of Hydraulic  Electric Engineering  Wuhan    China LI Rong Wuhan University of hydraulic  Electric Engineering  W 《国际泥沙研究》1997,(3)

LINTRODUCTIONJinghongHydraulicPowerPlant,locatedintheload,erreachesofLanchangmyer,trib.ofMekong,isintheNorthOfJinghongCity.Thepowerstationisamultipurposehydro-junction,includingelectricpowergeneration,shipping,floodcontrol,cultivahonandwatersupply.SimaoPort,animportanttransportcenterinSimaoDistriCt,YunnanProvince,isabollt80kmaamsuPStreamofthedam.Anerthereservoirisimpounded,thewaterstagewillriseandagreatamountofsedimentwillbedepositedintheriverbedinevitably.Asaresult,itisverylikelyt…  相似文献   

用SINS／GPS进行动态重力矢量测量的理论与方法     

董绪荣  陶大欣 《测绘学院学报》1996,(4)

ＳＩＮＳ／ＧＰＳ组合导航技术为研究地球重力场开辟了一条崭新的探索途径。可以在运动过程中同时测定重力异常和垂线偏差，从而实现真正的动态矢量重力测量。本文研究了这种新理论方法的数学模型及实现方法，并针对重力扰动矢量的确定探讨了这种新技术的分辨率。  相似文献   

GIM和不同约束条件相结合的BDS差分码偏差估计   总被引：1，自引：0，他引：1  

姚宜斌  刘磊  孔建  冯鑫滢 《测绘学报》2017,46(2):135-143

现阶段BDS卫星和地面跟踪站数量较少,用BDS单系统获取的DCB精度有限,针对此问题,本文基于CODE GIM,采用两种不同的"零均值"基准约束方案(分别称为约束1和约束2),选取2015年(DOY002-090)MGEX的BDS数据,求解BDS的DCB,并对其进行精度评估。结果表明,两种约束方案下,卫星DCB差值整体趋势一致,DCBC2I-C7I、DCBC2I-C6I的系统性偏差分别约为-3.3ns和1.2ns,接收机DCB的系统性偏差与卫星DCB大小相同,符号相反。相对于约束1,施加约束2后,IGSO和MEO卫星DCB估值更加稳定(DCBC2I-C7ISTD最大改善21%,DCBC2I-C6ISTD最大改善13%),IGSO和MEO卫星的稳定性(分别在0.1ns和0.2ns左右)优于GEO卫星(0.150.32ns)。约束2的DCB估值效果不仅与CAS/DLR产品有较好的一致性(Bias:-0.40.2ns),而且顾及了BDS卫星DCB间的稳定性差异。两种约束方案下,BDS接收机DCB的STD无明显变化,说明约束的选择对BDS接收机DCB的稳定性无明显影响。BDS接收机DCB稳定性整体上优于1ns,中高纬度区域较好(STD 0.4ns左右),低纬度区域稍差(STD 0.81ns)。  相似文献   

基于北斗反射信号的支持向量回归机海面风速反演研究     

涂满红  曹云昌  康金侠 《气象与环境科学》2017,40(2):60-65

随着全球导航卫星系统的发展,一种基于导航卫星反射信号(GNSS-R)的海洋遥感技术成为近年来研究的热点。为研究GNSS-R测风方法,分析了海面风速与反射信号时延功率之间的关系,同时结合机器学习方法中的支持向量回归机方法,将反射信号时延功率作为训练标签,最终完成海面风速的反演。将"北斗反射信号海风海浪探测系统——山东示范站"项目期间海风海浪系统的探测结果与同期风速仪探测结果进行对比分析,结果表明,两者具有很好的一致性,海面风速的反演精度为2.4 m/s,证明了基于北斗反射信号的支持向量回归机海面测风方法是可行的。  相似文献   

GPS/INS组合导航系统抗差滤波器设计   总被引：5，自引：0，他引：5  

何秀凤  陈永奇 《测绘学报》1998,27(2):177-184

常规Ｋａｌｍａｎ滤波器已经广泛用于ＧＰＳ／ＩＮＳ组合导航系统,其中假设系统动态模型和噪声统计特性是精确已知的。事实上,这种假设是不符合实际情况的。在组合导航系统中,惯性测量器件的质量不稳定,ＧＰＳ测量误差受外界环境的影响,因而对组合导航系统进行抗差设计是十分必要的。本文利用对策论设计了能使不确定噪声下性能最好的极小极大抗差滤波器,并将其应用到ＧＰＳ／ＩＮＳ组合导航系统中。考虑一个ＩＯ状态的ＧＰＳ／  相似文献   

Analysis on the controlled nonlinear motion of a test bed AUV–SNUUV I     

Kihun  Hang S.   《Ocean Engineering》2007,34(8-9):1138-1150

This paper describes the estimation of hydrodynamic coefficients and the control algorithm based on a nonlinear mathematical modeling for a test bed autonomous underwater vehicle (AUV) named by SNUUV I (Seoul National University Underwater Vehicle I).A six degree of freedom mathematical model for SNUUV I is derived with linear and nonlinear hydrodynamic coefficients, which are estimated with the help of a potential code and also the system identification using multi-variable regression.A navigation algorithm is developed using three ranging sonars, pressure sensor and two inclinometers keeping towing tank applications in mind. Based on the mathematical model, a simulation program using a model-based control algorithm is designed for heading control and wall following control of SNUUV I.It is demonstrated numerically that the navigation system together with controller guides the vehicle to follow the desired heading and path with a sufficient accuracy. Therefore the model-based control algorithm can be designed efficiently using the system identification method based on vehicle motion experiments with the appropriate navigation system.  相似文献   

北斗卫星导航系统的毫米级精度变形监测算法与实现   总被引：1，自引：1，他引：0  

肖玉钢  姜卫平  陈华  袁鹏  席瑞杰 《测绘学报》2016,45(1):16-21

研究了北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)毫米级精度变形监测算法。首先改进了TurboEdit方法,以能够探测到1周的小周跳;针对BDS星座结构给出更为高效的独立双差观测值搜索方法;对于模糊度固定,采用决策函数和序贯模糊度固定相结合的方法。在此基础上,研制了BDS变形监测软件。最后,利用变形监测试验平台的实测数据,从星座分布、解算精度等方面分析了BDS在变形监测中应用的可行性。结果表明,目前在试验区域内BDS与GPS在卫星几何分布等方面基本相当。BDS的短基线解算精度略低于GPS,但仍可达到平面1mm以内、高程2mm以内的精度水平。  相似文献