地球空间Web服务数据交换机制的设计与实现

为了支持多源、异构的地球空间数据在互联网上异步、可靠的传输,基于开放地理信息Web服务体系（OWS）,提出了基于消息中间件的空间数据交换方法。首先分析了当前地球空间数据交换的研究现状及相关技术,指出了当前地球空间数据交换方式存在效率低等诸多方面的不足,特别是由于目前很多OWS实现都是基于HTTP的Web服务模式,服务之间的数据交换是无状态和不可靠的。其次介绍了消息中间件规范,设计了基于消息中间件的空间数据交换体系结构,并对该体系结构的各组成部分进行了详细阐述。最后基于Java消息服务（JMS）、Web要素服务（WFS）、Web坐标转换服务（WCTS）和Web制图服务（WMS）,实现了一个基于消息中间件的空间数据交换系统实例,验证了方法的可行性。     

一个生态传感网的Web处理服务平台

随着近年来 Web 服务技术的日益成熟,越来越多的地理空间资源和处理功能以在线 Web 服务的形式发布在网络中,数据的共享和互操作性变得更加重要。WPS(Web Processing Service)便是由 OGC(Open Geospatial Consortium)推出的空间信息的共享和互操作的规范,采用Web服务技术来实现空间数据处理的共享和互操作。本文介绍了我们基于 OGC WPS 标准开发的一个用于生态环境领域的空间数据处理平台,并选取对生态水文研究有重大意义的日均蒸散量计算模型验证了平台的可行性和实用性。     

基于空间领域本体的动态工作流模型研究

OGC(Open Geospatial Consortium)提出的Web服务编排方法可以通过组合、协调各种空间信息Web服务,形成一种服务的工作流OWS2(OGC Web Services2),但这属于精确匹配的静态工作流。提出了一种基于本体和规则的动态工作流模型(Dynamic Work Flow Model based on Ontology and Rule,DWFMOR),它是对OWS2的改进。本模型首先针对空间信息的领域特征建立了相应的领域本体,基于这些本体设计了用于推理的工作流规则引擎,并使用protégé本体编辑器和Jena推理机进行了实现,最终建立了一个用于空间信息服务的工作流原型系统。实验表明,基于空间领域本体的工作流模型不仅可以根据业务的需求自动地查找和匹配空间信息Web服务,还可以动态地形成空间信息Web服务工作流。     

改进空间信息服务质量的设计策略

针对分布式空间信息领域服务的特点,结合“国家科学数据共享工程”的开发实践,提出了改进空间服务质量的3种策略：针对组件纵向关系的设计,采用面向服务结构和中心元数据服务器对OGC服务框架的改进策略;针对组件横向关系的设计,引入面向方面编程的策略;针对空间信息的领域特点,采用地图服务和空间数据缓冲池的设计策略。给出了一个原型系统实现的拓扑结构和相应的测试数据,验证了3种策略优越性。     

Business logic for geoprocessing of distributed geodata

This paper describes the development of a business-logic component for the geoprocessing of distributed geodata. The business logic acts as a mediator between the data and the user, therefore playing a central role in any spatial information system. The component is used in service-oriented architectures to foster the reuse of existing geodata inventories. Based on a geoscientific case study of groundwater vulnerability assessment and mapping, the demands for such architectures are identified with special regard to software engineering tasks. Methods are derived from the field of applied Geosciences (Hydrogeology), Geoinformatics, and Software Engineering.In addition to the development of a business logic component, a forthcoming Open Geospatial Consortium (OGC) specification is introduced: the OGC Web Processing Service (WPS) specification. A sample application is introduced to demonstrate the potential of WPS for future information systems.The sample application Geoservice Groundwater Vulnerability is described in detail to provide insight into the business logic component, and demonstrate how information can be generated out of distributed geodata. This has the potential to significantly accelerate the assessment and mapping of groundwater vulnerability.The presented concept is easily transferable to other geoscientific use cases dealing with distributed data inventories.Potential application fields include web-based geoinformation systems operating on distributed data (e.g. environmental planning systems, cadastral information systems, and others).     

Development of the Arctic Research Mapping Application (ARMAP): Interoperability challenges and solutions

Ensuring interoperability between WebGIS applications is essential for maximizing access to data, data sharing, and data manipulation. Interoperability is maximized through the adoption of best practices, use of open standards, and utilization of spatial data infrastructure (SDI). While many of the interoperability challenges like infrastructure, data exchange, and file formats are common between applications, some regions like the Arctic present specific challenges including the need for presenting data in one or more polar projections. This paper describes the Arctic Research Mapping Application (ARMAP) suite of online interactive maps, web services, and virtual globes (the ARMAP suite; http://armap.org/) and several of the interoperability challenges and solutions encountered in development to date. ARMAP is a unique science and logistic tool supporting United States and international Arctic science by providing users with the ability to access, query, and browse information and data. Access to data services include a text-based search utility, an Internet Map Server client (ArcIMS), a lightweight Flex client, ArcGIS Explorer and Google Earth virtual globes, and Open Geospatial Consortium (OGC) compliant web services, such as Web Map Service (WMS) and Web Feature Service (WFS). Through the ARMAP suite, users can view a variety of Arctic map layers and explore pertinent information about United States Arctic research efforts. The Arctic Research Logistics Support Service (ARLSS) database is the informational underpinning of ARMAP. Avoiding duplication of effort has been a key priority in the development of the ARMAP applications. The ARMAP suite incorporates best practices that facilitate interoperability such as Federal Geographic Data Committee (FGDC) metadata standards, web services for embedding external data and serving framework layers, and open standards such as Open Geospatial Consortium (OGC) compliant web services. Many of the features and capabilities of ARMAP are expected to greatly enhance the development of an Arctic SDI.     

The OGC web coverage processing service (WCPS) standard

Imagery is more and more becoming integral part of geo services. More generally, an increasing variety of sensors is generating massive amounts of data whose quantized nature frequently leads to rasterized data structures. Examples include 1-D time series, 2-D imagery, 3-D image time series and x/y/z spatial cubes, and 4-D x/y/z/t spatio-temporal cubes. The massive proliferation of such raster data through a rapidly growing number of services make open, standardized service interfaces increasingly important. Geo service standardization is undertaken by the Open GeoSpatial Consortium (OGC). The core raster service standard is the Web Coverage Service (WCS) which specifies retrieval based on subsetting, scaling, and reprojection. In 2008, OGC has issued a companion standard which adds flexible, open-ended coverage processing capabilities. This Web Coverage Processing Service (WCPS) specifies a coverage processing language allowing clients to send requests of arbitrary complexity for evaluation by the server. This contribution reports on the WCPS standard by giving an introduction to its coverage model and processing language. Further, design rationales are discussed, as well as background and relation to other OGC standards. 1-D to 4-D use case scenarios illustrate intended use and benefits for different communities. Although the paper focuses on conceptual issues, the WCPS reference implementation, PetaScope, is briefly addressed. The author is co-chair of the coverage-related working groups in OGC.     

基于本体的服务网络平台及其构建方法

在基于语义关系的大规模Web服务组织结构：服务网络模型的基础上,构建了服务网络系统平台。提供了对Web服务和服务关系的描述,使得Web服务的自动化处理成为可能。设计了可动态优化的服务网络系统内核,实现了服务网络的数据存储、网络优化和关系挖掘;设计和实现了系统创建维护工具、系统服务增长工具、可视化工具等一整套核心工具;给出了服务关系构成建的基本方法和流程,完善了网络结构。最后,一些基于服务网络的应用证明了该系统的有效性和广泛适用性。     

基于OGC WMS规范的WebGIS开发与应用

WebGIS是Internet技术与地理信息系统技术相结合的产物。通过引入开放地理信息系统联盟(OGC)的WMS规范,探讨了实现基于OGC WMS规范的WebGIS的关键技术和开发方案。在此基础上,提出了一个具体的实现步骤和方法,将其应用到陕西防汛抗旱服务平台开发中,取得了较好的效果。     

Web Service下的分布式事务处理研究与实现——基于Tomcat、Axis和JOTM

分析了Web Service以及分布式事务处理的相关技术,对Web Service下的事务处理以及分布式事务处理作了深入的研究.利用开放源代码的平台Tomcat、Axis和JOTM之间的集成,实现了Web Service下的分布式事务处理.     

Geospatial information system for agricultural monitoring

This paper describes a distributed system for agricultural monitoring in Ukraine at two levels, namely, at ministerial level and at agricultural enterprise level. Crop monitoring is performed using data and products obtained by moderate and high-resolution remote sensing satellites. The system includes a geoportal with a Web interface and a desktop geographic information system (GIS) with additional functions of automatic data retrieval and business-logic analysis. The system is constructed using open-source software that conforms to OGC standards for geospatial information management.     

基于移动互联网和Web Service的智能农业系统

基于移动互联网和Web Service技术,采用ZigBee技术构建底层WSN,利用移动通信网络实现信息传输,利用HTTP协议和JSON数据格式进行数据的交换,实现Android客户端和Web Service服务端的设计与开发,面向智能农业环境构建了包含环境指标、历史数据查询、手动控制、系统设置等功能为一体的智能农业APP系统.根据预设农作物生长周期需要的环境参数,通过Android手机进行展示和操作管理,提高了农业系统的智能化水平,改善了落后的农业管理方式.     

Monitoring and evaluating the quality of Web Map Service resources for optimizing map composition over the internet to support decision making

Over the past 10 years, there have been great advances in the interoperability technologies in geographic information science. More than 10,000 map layers are available online today through Open Geospatial Consortium (OGC) specified interfaces, such as Web Map Service (WMS), Web Feature Service (WFS), and Web Coverage Service (WCS). These map layers are persistently serving the geospatial communities; however, our empirical study found that their potential value has not been fully exploited. Frequently, a targeted map cannot be composed because some published map servers are unavailable. This problem becomes more serious when a map is composed of several layers from different servers. These services are geographically distributed and maintained by various hosts; therefore, simply waiting for service improvement on the host side cannot solve this problem. In this paper, we proposed a new approach and developed a mechanism that allows clients to select the best map layers at run-time. The selection is based on the results of continuous monitoring and evaluation of the quality of WMSs. Based on Service Oriented Architecture (SOA), this approach includes quality monitoring and evaluation modules. Quality factors are taken into account during the process of registration, search, and bind. The OGC capability document is extended to include WMS quality information. Three prototype systems were developed in this study to demonstrate: (a) how WMS layers are monitored and evaluated, (b) how the subjective evaluation of WMS quality by a user is collected, and (c) how this can be a feasible method to fuse WMS resources suitable for decision making.     

基于GIS的气象信息标准化服务平台的设计与实现

随着气象资料服务不断格点化、精细化,对气象数据基于GIS(geographic information system,地理信息系统)的显示发布要求进一步提高。当前各气象业务系统在建设时往往存在重复处理气象数据及开发整合地理信息系统的现象,重复开发基于地理信息的可视化功能会造成资源浪费,延长开发周期。该文根据实际业务需求,集成了多源异构的气象数据,设计实现了基于GIS的气象信息标准化服务平台。该平台主要依托CIMISS(全国综合气象信息共享平台)数据接口、各类气象资料观测数据文件,依照地理信息数据图层金字塔分级方式,将气象数据进行重新组织,以Web方式提供标准化PaaS(platform as a service,平台即服务)服务,包括地图服务、地理覆盖服务和地理要素服务,以更便捷、更安全、更全面的方式向本级和下级单位各业务部门提供气象数据GIS服务(包含GIS和数据服务)。该平台在江苏省气象局多个气象业务系统中投入应用,有效减少了业务系统建设环节中的气象资料可视化重复开发所造成的资源浪费,收到了良好的应用效果。     

基于REST的空间信息服务互操作协议的研究

REST式的Web服务充分地利用HTTP协议的分布式特性,可以使Web服务的开发变得更加高效、简洁、 可维护。着力于REST式空间信息服务互操作协议研究,通过分离OGC Web服务定义中的动作、意图和表示的方 式,确定服务中的资源。最后将REST的“资源”概念与空间信息“数据”共享结合起来,利用H"I"I'P协议定义的操作, 设计了RES"I'式空间信息服务互操作规范REST=WMS与REST-WFS.     

基于Kriging的三维地质体建模方法研究

对几种三维空间数据模型进行了比较,总结了克里格（Kriging）插值方法在三维地质体建模方面的种种优点。在此基础上,借助于GSTL开源地质统计学库wxWidgets界面库,在Dev-cpp开发环境下开发了一个三维矿体数据的克里格插值系统,为矿体的三维可视化提供了数据支持。该系统实现了Kriging插值、变异函数拟合模型拟合程度的验证一交叉验证以及特定格式的结果输出等功能。     

A Web Ontology Service to facilitate interoperability within a Spatial Data Infrastructure: Applicability to discovery

Ontologies are used within the context of Spatial Data Infrastructures to denote a formally represented knowledge that is used to improve data sharing and information retrieval. Given the increasing relevance of semantic interoperability in this context, this work presents the specification and development of a Web Ontology Service (WOS), based on the OGC Web Service Architecture specification, whose purpose is to facilitate the management and use of lexical ontologies. Additionally, this work shows how to integrate this service with Spatial Data Infrastructure discovery components in order to obtain a better classification of resources and an improvement in information retrieval performance.     

A Web Ontology Service to facilitate interoperability within a Spatial Data Infrastructure: Applicability to discovery

Ontologies are used within the context of Spatial Data Infrastructures to denote a formally represented knowledge that is used to improve data sharing and information retrieval. Given the increasing relevance of semantic interoperability in this context, this work presents the specification and development of a Web Ontology Service (WOS), based on the OGC Web Service Architecture specification, whose purpose is to facilitate the management and use of lexical ontologies. Additionally, this work shows how to integrate this service with Spatial Data Infrastructure discovery components in order to obtain a better classification of resources and an improvement in information retrieval performance.     

面向传感器集成应用的地学观测数据发布方法研究

随着传感器的应用深入,越来越多的传感器观测数据亟需实现发布共享。通过将 GPS 模块与温度传感器的集成应用,把获取的空间位置信息数据与温度信息按预定格式存储,模拟了地理传感器观测数据的方式。基于开放地理空间联盟的传感器观测服务标准,应用开源软件 Apache、编程语言 Perl 和 CGI 脚本等设计和部署了传感器观测数据实时共享服务器,实现了观测数据的实时共享发布。