MapInfo中的坐标系与地图数据的转换   总被引：9，自引：0，他引：9  

徐建刚  朱承霖 《现代测绘》2003,26(3):36-38

本文就MapInfo系统中地图投影坐标系和有关GIS数据的转换作了一些有益的探讨，并就目前比较多的各种地图数据转换成经纬度投影坐标(例如：WGS84投影坐标)进行了尝试和研究，以供各位读者参考，也希望相关方面的专业人士能给予纠正及补充。  相似文献   

ATOVS辐射率资料的直接变分同化试验研究   总被引：19，自引：4，他引：19  

潘宁  董超华  张文建 《气象学报》2003,61(2):226-236

文中采用增量三维变分 ( 3D Var)同化方法 ,对先进的微波探测装置 (AMSU A)探测的辐射亮温资料与常规探空资料在MM5中尺度数值预报模式中的直接同化和预报进行对比试验研究。结果表明 ,同化AMSU A辐射亮温资料对中高层温度分析场的影响最明显 ,对MM5模式的温度和水汽混合比预报有总体上的正效应 ,但对降水预报的改善作用不大  相似文献   

国家卫星气象中心气象卫星资料存档系统   总被引：5，自引：4，他引：5  

钱建梅  郑旭东 《应用气象学报》2003,14(6):756-762

论述了国家卫星气象中心的气象卫星资料存档系统构成、存储数据的编目组织、应用软件的逻辑关联结构、层次框架结构及组织结构，介绍了应用软件主要功能和流程图，对存档系统建设中的经验进行了总结。  相似文献   

网络编程实现气象卫星资料的传输   总被引：3，自引：2，他引：3       下载免费PDF全文

赵立成  关彤 《应用气象学报》2003,14(4):395-401

气象卫星应用系统是一个异构平台的分布式处理系统，由多机协同完成资料接收、传输、处理、存档与产品分发等任务。使用网络编程进行气象卫星资料的传输，可以提高资料的传输实效，确保分布式环境下不同系统之间的同步与资料的可靠性，从而保证气象卫星产品及时提供用户使用。该文介绍了网络编程技术在气象卫星资料传输方面的应用。  相似文献   

Mapping of Land-Atmosphere Heat Fluxes and Surface Parameters with Remote Sensing Data   总被引：3，自引：0，他引：3  

Francesca Caparrini  Fabio Castelli  Dara Entekhabi 《Boundary-Layer Meteorology》2003,107(3):605-633

A variational data assimilation scheme is used to infer two key parameters ofthe surface energy balance that control the partitioning of available energy intolatent, sensible, and ground heat fluxes (LE, H, and G). Remotely sensedland surface temperature (LST) is the principal data source. Maps ofdiurnal energy balance components are presented for a basin with varied landcover (Arno Basin, Italy) for a 18-day period in July 1996.Given available energy, the major unknown (dimensionless) parameters requiredfor partitioning among fluxes are: (1) Landscape effects on near-surfaceturbulence as captured by the bulk heat transfer coefficient C_BN underneutral conditions and (2) surface control of the relative magnitudes of LEand H as represented by the evaporative fraction E_F. The data assimilationscheme merges 1.1-km resolution remotely sensed LST images (based onoptical, thermal and microwave measurements from two different satelliteplatforms) into a parsimonious model of heat diffusion. Both the measurementsand the model predictions are considered uncertain. Posterior error statisticsthat represent uncertainty of the estimated parameters are also derived.Maps of C_BN show spatial patterns consistent with the dominant land useand basin physiography. Daily maps of E_F exhibit spatial variationscorresponding to land cover and land use – the day-to-day variations inE_F show fluctuations consistent with rain events and drydowns experiencedduring the period. Based on these parameters and available environmentalvariables, maps of diurnal LE and H may be produced (in this paper daytimeLE maps are reported).The application demonstrates that remotely sensed land surface temperaturesequences contain significant amount of information of the partitioning ofavailable energy among the fluxes. The variational data assimilation frameworkis shown to be an efficient and parsimonious approach without reliance onempirical relationships such as those based on vegetation indices.  相似文献   

数字化地震前兆资料的管理和初步应用     

温岩  李忠伟  张晨侠 《东北地震研究》2003,19(2):62-67

介绍了吉林省地震局前兆台网中心的软硬件构成、数据库设计、前兆台网中心的运行以及数字化前兆资料的管理，并对数字化前兆资料在地震预报中的应用进行了初步探讨。  相似文献   

一种新型绘图软件在气象中的应用初探   总被引：4，自引：1，他引：4       下载免费PDF全文

张秀丽  徐桂荣等 《气象科学》2002,22(2):223-229

介绍了Vis5D可视化软件在微机上的运行环境和安装过程，Vis5D系统的三维图形分析、显示功能及各种图形浏览模式，描述了Vis5D系统可接受的数据格式，给出了将CrADS格式的数据文件转换为v5d格式的方法。并利用该系统对MAPS数值模式的输出产品进行了初步的可视化试验。  相似文献   

辽宁地震前兆台网中心的数据管理与服务   总被引：2，自引：0，他引：2  

谷光裕  魏柳  曹凤娟 《东北地震研究》2002,18(3):68-73

简要介绍了辽宁地震前兆台网中心的软，硬件构成，叙述了该中心在MsWindowsNT操作平台上实现数据传输，数据管理和数据服务的系统集成，并通过局域网实现前兆数据共享，文章中对地震前兆数字观测和模拟观测数据流程做了较详细阐述。  相似文献   

集合预报系统中客观分析方案的并行化实现          下载免费PDF全文

王惠玲 《应用气象学报》2002,13(2):254-256

从串行程序分析、并行方案选择到具体算法实现, 依次介绍了基于神威机的集合数值天气预报系统中“客观分析子系统”的并行化过程, 并给出了并行化后的性能评测。  相似文献   

The northern European geoid: a case study on long-wavelength geoid errors   总被引：1，自引：1，他引：1  

O. C. D. Omang  R. Forsberg 《Journal of Geodesy》2002,76(6-7):369-380

 The long-wavelength geoid errors on large-scale geoid solutions, and the use of modified kernels to mitigate these effects, are studied. The geoid around the Nordic area, from Greenland to the Ural mountains, is considered. The effect of including additional gravity data around the Nordic/Baltic land area, originating from both marine, satellite and ground-based measurements, is studied. It is found that additional data appear to increase the noise level in computations, indicating the presence of systematic errors. Therefore, the Wong–Gore modification to the Stokes kernel is applied. This method of removing lower-order terms in the Stokes kernel appears to improve the geoid. The best fit to the global positioning system (GPS) leveling points is obtained with a degree of modification of approximately 30. In addition to the study of modification errors, the results of different methods of combining satellite altimetry gravity and other gravimetry are presented. They all gave comparable results, at the 6-cm level, when evaluated for the Nordic GPS networks. One dimensional (1-D) and 2-D fast Fourier transform (FFT) methods are also compared. It is shown that even though methods differ by up to 6 cm, the fit to the GPS is essentially the same. A surprising conclusion is that the addition of more data does not always produce a better geoid, illustrating the danger of systematic errors in data. Received: 4 July 2001 / Accepted: 21 February 2002  相似文献