SEDIMENTATION PROBLEMS IN THE ACCESS CHANNELS OF THE GEZHOUBA NAVIGATION LOCKS     

TU Qiming Engineer  Navigation Office of the Three Gorges Project  Ministry of Communication 《国际泥沙研究》1991,(3)

Sedimentation problems in the access channels of the Gezhouba Navigation Locks at the Third Channel, which is of great importance for the navigation are discussed in this paper:1) the cause of deposition in the access channel, 2) effects of the deposit--reducing embankment and sediment sluices and 3) the relation between the sediment deposition at the Third Channel and the sediment discharge of the Yangtze River. Analyzing a four years' field data of sounding records with respect to the lock operation, it can be seen that the flood release through the navigation channel resulted in severe deposition, especially the sediment deposits induced by eddy current are difficult to be cleared off by flushing and jeopardize the working conditions of the lock operation. It is obvious that the flood release through the navigation channel should be minimized. In order to reduce the sediment deposits caused by eddy current attempts should be made to adjust the alignment of the boundaries and layout of the entrance of access channels.  相似文献   

基于GNSS的MODIS大气可降水量校正模型     

马赛  岳迎春  上官明  邹玉学  丁茂华 《南京气象学院学报》2021,13(2):154-160

MODIS大气可降水量（PWV）空间分辨率高但易受云雨等环境因素影响,精度不高.GNSS PWV 空间分辨率较低但具有全天候、不受天气影响、精度高的优点.研究表明两者存在显著的线性相关性,结合两者的优点,基于GNSS PWV校正MODIS PWV可获取大面积高精度的PWV.针对传统的线性回归校正模型没有考虑云、气溶胶等的影响使两种数据线性相关性变差的问题,本文在传统的线性校正模型上增加了使用年积日的非线性周期项的方法来构建校正模型.利用2017—2019年香港地区GNSS对流层延迟与MODIS近红外数据,使用频谱分析线性残差项,结果表明残差具有显著的年周期.对比传统模型,本文模型的平均绝对误差、平均相对误差、均方根误差和拟合度都有明显的改善,表明本文模型可行有效且精度较高.  相似文献   

尾标定位系统在长排列地震调查中的应用     

何水原 《南海地质研究》2006,(1):139-149

本文通过Seamap公司生产的Buoylink EX GPStrackingsystem尾标定位系统在长排列地震调查中的应用，阐述了尾标定位系统的工作原理，以及它在地震调查中的重要性和实用性，为常规地震及三维地震调查中尾标定位的使用提供参考。  相似文献   

GPS车载导航系统技术趋势浅析   总被引：7，自引：0，他引：7  

曹晓航 《现代测绘》2006,29(1):14-17

本文通过对GPS车载导航系统的构成及其国内外发展现状的分析,阐明了我国GPS车载导航系统将向信息终端融合化、交通信息实时化、信息服务平台化、数据更新网络化方向发展的技术趋势。  相似文献   

在GPS导航定位中坐标转换参数的确定   总被引：2，自引：0，他引：2  

冯林刚  赵永贵 《现代测绘》2004,27(2):30-32

介绍GPS导航定位测量中坐标转换参数的确定方法，并通过具体实例分析该方法的可行性和实用性。  相似文献   

Penalized GNSS Ambiguity Resolution   总被引：1，自引：1，他引：1  

P. J. G. Teunissen 《Journal of Geodesy》2004,78(4-5):235-244

Global Navigation Satellite System (GNSS) carrier phase ambiguity resolution is the process of resolving the carrier phase ambiguities as integers. It is the key to fast and high precision GNSS positioning and it applies to a great variety of GNSS models which are currently in use in navigation, surveying, geodesy and geophysics. A new principle of carrier phase ambiguity resolution is introduced. The idea is to give the user the possibility to assign penalties to the possible outcomes of the ambiguity resolution process: a high penalty for an incorrect integer outcome, a low penalty for a correct integer outcome and a medium penalty for the real valued float solution. As a result of the penalty assignment, each ambiguity resolution process has its own overall penalty. Using this penalty as the objective function which needs to be minimized, it is shown which ambiguity mapping has the smallest possible penalty. The theory presented is formulated using the class of integer aperture estimators as a framework. This class of estimators was introduced elsewhere as a larger class than the class of integer estimators. Integer aperture estimators, being of a hybrid nature, can have integer outcomes as well as non-integer outcomes. The minimal penalty ambiguity estimator is an example of an integer aperture estimator. The computational steps involved for determining the outcome of the minimal penalty estimator are given. The additional complexity in comparison with current practice is minor, since the optimal integer estimator still plays a major role in the solution of the minimal penalty ambiguity estimator.  相似文献   

三维扫描仪协同GNSS-RTK在复杂地形测量中的应用研究     

朱艳军  张国峰  张海峰 《北京测绘》2020,(5):718-723

建设工程进行过程中施工现场地形复杂且呈现动态变化,施工过程中工程实体形度和施工操作对周围环境造成的影响都需要进行监控测量,建设工程施工测量是复杂地形测量的代表。本文讨论复杂地形监控测量过程中利用三维激光扫描测量的快速获取数据,获取到的据利用专业的处理软件处理后获得监控测量物体的立体成像结果,再利用全球导航卫星系统实时动态载波相位差分技术(GNSS-RTK)辅助测量监控点的空间坐标变化以及高程差。两者协同应用可以既快速又准确的进行复杂地形的监控测量。  相似文献   

GNSS虚拟仿真教学系统设计与实现     

袁德宝  孙文彬  蒋金豹  崔希民 《北京测绘》2020,(5):728-730

GNSS卫星导航与定位一直是测绘工程专业的主要必修课之一。为了协助学生们能够更好地学习GNSS导航应用的相关知识,提高实际的仪器操作技能,本文设计了GNSS虚拟仿真教学系统,通过3DS MAX对GNSS仪器设备和测量场景等进行三维模型构建,并基于AE动画渲染,利用C++语言进行仿真系统开发,实现了仪器介绍,安装演示,静态作业,RTK作业以及参数计算等功能,探索了虚拟仿真教学应用模式,取得了一定的教学成果。  相似文献   

SINS／GPS组合系统数据处理的质量控制方法研究   总被引：1，自引：0，他引：1  

董绪荣 《测绘学院学报》1994,(4)

ＳＩＮＳ／ＧＰＳ组合系统是一种高效的动态大地测量方法。本文探讨这种组合系统数据处理的统计质量控制理论。  相似文献   

西北区野外地质调查中北斗卫星通讯与定位技术应用研究     

伍锦程  王占昌  石小亚 《地质力学学报》2012,18(3):282-287

在分析北斗一号卫星导航定位系统应用特点的基础上,介绍了基于北斗一号卫星通讯与定位技术的野外地质调查工作组网架构、野外地质调查工作管理与服务平台,并对北斗卫星系统在西北区野外地质调查中的应用进行分析总结。   相似文献