Synchronization of Radar Observations with Multi-Scale Storm Tracking     

YANG Hongping  Jian ZHANG  Carrie LANGSTON 《大气科学进展》2009,26(1):78-86

The 3-D radar reflectivity data has become increasingly important for use in data assimilation towards convective scale numerical weather prediction as well as next generation precipitation estimation. Typically, reflectivity data from multiple radars are objectively analyzed and mosaiced onto a regional 3-D Cartesian grid prior to being assimilated into the models. One of the scientific issues associated with the mosaic of multi-radar observations is the synchronization of all the observations. Since radar data is usually rapidly updated (～every 5--10 min), it is common in current multi-radar mosaic techniques to combine multiple radar' observations within a time window by assuming that the storms are steady within the window. The assumption holds well for slow evolving precipitation systems, but for fast evolving convective storms, this assumption may be violated and the mosaic of radar observations at different times may result in inaccurate storm structure depictions. This study investigates the impact of synchronization on storm structures in multiple radar data analyses using a multi-scale storm tracking algorithm.  相似文献   

差分GPS水下立体定位系统浮标姿态的测量   总被引：4，自引：0，他引：4  

蔡艳辉  章传银  王泽民  程剑  秘金钟 《测绘科学》2005,30(3):49-50

三维数字罗盘可以实时输出载体的二维姿态和地理方位角。在差分GPS精密水下立体定位系统中,可以用于GPS浮标姿态测定,进行GPS天线坐标实时三维改正。本文对三维数字罗盘工作原理进行了简要介绍,并针对三维数字罗盘与GPS同步问题进行了详细分析,同时给出了GPS天线坐标改正公式。  相似文献   

基于改进的自适应反馈混沌系统同步     

李青芮  陶文华  孙娜 《华东地质学院学报》2009,32(3):293-297

基于LaSalle不变定理和Lyapunov方法,针对混沌系统同步问题提出了一种改进的自适应反馈方法。与一般线性反馈系统不同,这种方法能自动调整更新规则的可变反馈变量。在该自适应更新规则的控制下,反馈强度可自动调整到新的自适应规则,从而使响应系统的状态全局同步于驱动系统的状态。Chen氏混沌系统和Lu氏混沌系统说明了所设计的自适应反馈方法的有效性。  相似文献   

The Importance of Time Synchronization in the Local Networks of the Science and Application Center for Lunar and Deep-space Exploration     

LIU Guoping  OUYANG Ziyuan  LI Chunlai  LIU Jianfeng National Astronomical Observatories  Chinese Academy of Sciences  Beijing  Peking University of Aeronautics  Astronautics  Beijing 《《地质学报》英文版》2004,78(5):1104-1108

The data acquisition stations and the data processing center of the Science and Application Center for Lunar and Deep-space Exploration (SACLuDE) are located at different geographical sites. They respectively have their own local networks and interconnect with each other through access to the core data network. This paper describes the clock drift in the computer and other networked devices building up the infrastructure of the above local networks. The network time variance of the stochastic model is also estimated. The poor precision of network synchronization will bring about potential hazards to the network operation and application running in the networks, which is clarified in the present paper. At the end of the paper, a cost-effective and feasible solution is proposed based on the Global Position System (GPS) and the Network Time Protocol (NTP).  相似文献   

关于省局域网远程访问的探讨     

赵晓云  薄建杰  李兵 《山西地震》2005,(3):36-38

随着人们对信息技术“灵活性”的要求,远程访问技术广为应用,为了外出工作人员的工作便利和节约经费,远程访问技术在山西省地震局的实施也迫在眉睫.在远程同步、安全维护和设备软件的管理等问题上,结合山西省地震局的实际情况,探讨了使用点对点协议PPP,远程访问服务器RAS,拨号安全服务器与调制解调器组合,拨号连接实现远程访问功能,防火墙、网关保护、病毒软件及网管软件等维护数据安全的可能性.  相似文献   

基于XML的多级异构空间数据库的同步架构   总被引：4，自引：0，他引：4  

解吉波  吴华意  龚健雅 《武汉大学学报(信息科学版)》2006,31(5):415-418

分析了多级异构空间数据库同步的关键问题和难点，提出了一种基于XML的多级异构空间数据的同步架构，该架构在“全国国土资源数据交换中心试点建设项目”中得到成功应用。  相似文献   

GPS接收机动态检定场中的时间同步问题   总被引：1，自引：0，他引：1  

李军正  李建文  郝金明  张峰 《测绘科学技术学报》2006,23(6):429-431

首先,阐述了时间同步问题在GPS接收机动态检测中的重要性.其次,就相机快门延迟检测原理、检测方法进行了详细的讨论,检测出所使用的相机快门时间延迟约为90 ms,但有时会出现突变,得出了仅仅依靠机械快门无法实现相机在动态条件下的同步拍摄的结论.然后,结合液晶快门的控制对相机时间同步等问题进行了讨论.最后,给出了数码相机配合液晶快门以实现相机高精度同步的方法.  相似文献   

《北京市规划信息发布系统》的特点与研制方法     

陈品祥  张保钢  刘鹏 《北京测绘》2006,(2):1-4,56

建立了规划信息发布系统的运行环境,加工整理、入库和发布了100多个GB的空间数据和多媒体数据,系统具有查询浏览、系统管理等功能,同时具有多窗口空间数据联动,方便的角色管理,灵活高效的海量数据发布等特点。系统的运行实现了规划信息共享,提高规划设计人员工作效率的预期目标。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1983,35(2):230-260

Book Reviewed in this article: Rabat: Urban Apartheid in Morocco . Janet Abu -Lughod . Marketplaces in a Developing Country: The Case of Western Nigeria . Isaac Ayinde Adalemo . Farming Development and Space: A World Agricultural Geography . Bernd Andreae . Section and Party: A Political Geography of American Presidential Elections, from Andrew Jackson to Ronald Reagan . J. Clark Archer and Peter J. Taylor . Women and Space: Ground Rules and Social Maps . Shirley Ardener , ed. European Progress in Spatial Analysis . R. J. Bennett , ed. The Origins of Academic Geography in the United States . Brian W. Blouet Geographic Perspectives on Global Problems . Ronald Reed Boyce . Seasonal Dimensions to Rural Poverty . Robert Chambers , Richard Longhurst and Arnold Pacey eds. The New Nationalism and the Use of Common Spaces: Issues in Marine Pollution and the Exploitation of Antarctica . Jonathan I. Charney , ed. Communications Tomorrow: The Coming of the Information Society . Edward Cornish , ed. The Design of Suburbia . Arthur Edwards . Explorer on the Northern Plains: Lieutenant Gouverneur K. Warren's Preliminary Report of Explorations in Nebraska and Dakota in the Years 1855–56–57. With an Introduction by Frank N. Schubert . The Changing Climate: Responses of the Natural Flora and Fauna . Michael J. Ford . Essentials of Physical Geography . Robert E. Gabler , Robert J. Sager , Sheila Brazier , and Daniel L. Wise. The Road to Jaramillo . William Glen . Valued Environments . John R. Gold and Jacquelin Burgess , eds. Proximity and Preference: Problems in the Multidimensional Analysis of Large Data Sets . Reginald G. Golledge and John N. Rayner , eds. A Search for Common Ground . Peter Gould and Gunnar Olsson , eds. Geography: Its History and Concepts . Arild Holt -Jensen . A Population Geography . Huw R. Jones . The Human Mosaic: A Thematic Introduction to Cultural Geography, 3rd ed. Terry G. Jordan and Lester Rowntree . Urban Social Geography: An Introduction . Paul Knox . The Anatomy of Job Loss: The How, Why and Where of Employment Decline . Doreen Massey and Richard Meegan . The Information Society as Post-Industial Society . Yoneji Masuda . Map Librarianship, 2nd ed. Harold Nichols . India: Cultural Patterns and Processes . Allen G. Noble and Ashok K. Dutt , eds. The God that Limps: Science and Technology in the Eighties . Colin Norman . Geography: An Introductory Perspective . Robert E. Norris , Keith D. Harries and John D. Vitek . The Politics of Technology Assessment . David M. O'Brien and Donald A. Marchand . Ethnic Segregation in Cities . Ceri Peach , Vaughan Robinson and Susan Smith , eds. Churches and Church Membership in the United States, 1980 . Bernard Quinn , Herman Anderson , Martin Bradley , Paul Goetting and Peggy Shriver . Energy in Australia: Politics and Economics . Hugh Saddler . Development from Above or Below? The Dialectics of Regional Planning in Developing Countries . Walter B. Stóuhr and D. R. Fraser Taylor , eds. Human Impact on the Ecosystem . Joy Tivy and Greg O'Hare . Plants and People: Vegetation Change in North America . Thomas R. Vale . The Mapmakers: The Story of the Great Pioneers in Cartography from Antiquity to the Space Age . John Noble Wilford .  相似文献   

基于Geodatabase的数据复制技术研究     

郑海鹰  张立朝  孙婷  唐汉松 《测绘学院学报》2007,(3)

G IS的飞速发展对数据分发和管理提出了新的要求,即野外用户的离线编辑、多级应用、分布式维护、故障恢复以及多项目数据管理等等。基于Geodatabase的数据复制技术为解决这些问题提供了可能。通过版本、复本(Rep lica)、同步、协调等几个关键技术,深入地研究了Geodatabase复制技术,为基于ArcG IS项目数据的分发、拷贝和分布式管理提供了解决方案和思路。  相似文献