球面等积网格系统生成算法与软件模型研究

利用全球离散网格系统管理海量空间信息是一种受到普遍关注的新途径,具有等积特性的网格系统在大范围遥感影像数据处理方面具有重要的理论意义和应用前景。文中论述的算法在二十面体展开图上建立坐标系描述不同剖分产生的多分辨率网格,利用施奈德多面体投影映射到球面。针对算法特点设计具有网络模拟功能的软件模型。实验结果表明,该软件模型具有较好的扩展性。     

Geodesic Discrete Global Grid Systems

In recent years, a number of data structures for global geo-referenced data sets have been proposed based on regular, multi-resolution partitions of polyhedra. We present a survey of the most promising of such systems, which we call Geodesic Discrete Global Grid Systems (Geodesic DGGSs). We show that Geodesic DGGS alternatives can be constructed by specifying five substantially independent design choices: a base regular polyhedron, a fixed orientation of the base regular polyhedron relative to the Earth, a hierarchical spatial partitioning method defined symmetrically on a face (or set of faces) of the base regular polyhedron, a method for transforming that planar partition to the corresponding spherical/ellipsoidal surface, and a method for assigning point representations to grid cells. The majority of systems surveyed are based on the icosahedron, use an aperture 4 triangle or hexagon partition, and are either created directly on the surface of the sphere or by using an equal-area transformation. An examination of the design choice options leads us to the construction of the Icosahedral Snyder Equal Area aperture 3 Hexagon (ISEA3H) Geodesic DGGS.     

基于GIS服务链的遥感影像分布式融合处理

提出了基于Web服务技术、OGC规范和工作流技术,以实现与平台无关的、具备流程编排能力的地理空间处理服务链框架,用于支持复杂的在线空间处理任务.在该框架基础上实现了一个在线遥感影像融合处理示例.该示例展示了利用OGC WCS、WPS,WSDL,UDDI和BPEL4WS等成熟的标准规范来构建GIS服务链,使得客户应用程序...     

An open source,server-side framework for analytical web mapping and its application to health

In this paper, we detail the design and the implementation of an open source, server-side web mapping framework for the analysis of health data. The framework forms part of a larger project, the goal of which is to provide an analytical web geographical information system (GIS) that enables health experts to analyse spatial aspects of health data. The aim of the framework is to provide a method for the dynamic and flexible spatial visualisation of health data to facilitate data exploration and analysis. Consequently, a dynamic thematic web mapping technique, an extension to the Open Geospatial Consortium (OGC) web map service standard, was developed. The technique combines a data query, processing technique and styling methodology on the fly to generate a thematic map. The resulting thematic map represents a virtual map layer that enables a user to rapidly visually summarise properties of a data-set. A test web interface was developed to assess the efficacy of the web mapping technique. As the dynamic web mapping method builds on existing OGC web mapping standards, it can be readily integrated with the existing lightweight slippy map web clients and virtual globes.     

基于WMS的WebGIS

介绍了Web地图服务规范,通过一种WebGIS的互操作模型实现了WMS,并详细描述了客户端的实现.     

Research and implementation of a universal workflow model to evaluate the soil fertility based on OGC Web Service

ABSTRACT

A method based on workflow technology and Open Geospatial Consortium (OGC) specification is proposed to establish a universal workflow conceptual model in the network environment. In this paper, the soil fertility evaluation conceptual model was developed as an evaluation method of soil fertility by analyzing the GIS-based fertility evaluation method and extracting the dynamic variable to verify the feasibility model. This validation process involves determining the instantiation of the conceptual model. The proposed conceptual model achieved the following goals. All data acquisition and processing functions were packaged into an OGC-compliant service model; these service models were organized into a processing chain in a certain order on the workflow platform by Petri-Net; the fertility evaluation was realized on the workflow platform by calling the processing chain. Results showed that processing functions and data can be shared in the network environment, and the network workflow model can be realized by the workflow technology. The successful implementation of fertility evaluation proved the feasibility of the network-based universal workflow conceptual model. In addition, the flexibility of our modeling method is demonstrated by reconstructing the workflow model.     

空间地理信息网络服务集成框架初探

本文在分析了W eb服务体系结构和OGC相关规范的基础上,提出了空间地理信息网络服务集成框架。框架由空间地理信息服务(提供者)、空间地理信息服务注册处(中介)和客户端(请求者)组成。并利用ESR I的空间地理信息网络服务雏形-ArcW eb,成功构建了一个简单的G IS应用。最后提出了要真正实现成熟的标准框架,还需要解决服务的标准化、空间数据传输以及地图数据显示等问题。     

Geospatial web services pave new ways for server-based on-demand access and processing of Big Earth Data

ABSTRACT

Big Earth Data has experienced a considerable increase in volume in recent years due to improved sensing technologies and improvement of numerical-weather prediction models. The traditional geospatial data analysis workflow hinders the use of large volumes of geospatial data due to limited disc space and computing capacity. Geospatial web service technologies bring new opportunities to access large volumes of Big Earth Data via the Internet and to process them at server-side. Four practical examples are presented from the marine, climate, planetary and earth observation science communities to show how the standard interface Web Coverage Service and its processing extension can be integrated into the traditional geospatial data workflow. Web service technologies offer a time- and cost-effective way to access multi-dimensional data in a user-tailored format and allow for rapid application development or time-series extraction. Data transport is minimised and enhanced processing capabilities are offered. More research is required to investigate web service implementations in an operational mode and large data centres have to become more progressive towards the adoption of geo-data standard interfaces. At the same time, data users have to become aware of the advantages of web services and be trained how to benefit from them most.     

The framework of a geospatial semantic web-based spatial decision support system for Digital Earth

Abstract

While significant progress has been made to implement the Digital Earth vision, current implementation only makes it easy to integrate and share spatial data from distributed sources and has limited capabilities to integrate data and models for simulating social and physical processes. To achieve effectiveness of decision-making using Digital Earth for understanding the Earth and its systems, new infrastructures that provide capabilities of computational simulation are needed. This paper proposed a framework of geospatial semantic web-based interoperable spatial decision support systems (SDSSs) to expand capabilities of the currently implemented infrastructure of Digital Earth. Main technologies applied in the framework such as heterogeneous ontology integration, ontology-based catalog service, and web service composition were introduced. We proposed a partition-refinement algorithm for ontology matching and integration, and an algorithm for web service discovery and composition. The proposed interoperable SDSS enables decision-makers to reuse and integrate geospatial data and geoprocessing resources from heterogeneous sources across the Internet. Based on the proposed framework, a prototype to assist in protective boundary delimitation for Lunan Stone Forest conservation was implemented to demonstrate how ontology-based web services and the services-oriented architecture can contribute to the development of interoperable SDSSs in support of Digital Earth for decision-making.     

Generalization Services on the Web—Classification and an Initial Prototype Implementation

Much progress has been made in the field of web-based cartography through standards developed by the Open Geospatial Consortium (OGC). While automated access and presentation of cartographic data have been defined, the services for automated generalization are yet to be standardized. This paper aims to show advantages of applying the service concept to generalization and suggests several classification schemas of generalization services at different levels of granularity. A detailed explanation of a real implemented Generalization Service is provided. We show how software developers can make their generalization functionality available as a service and how these services can be accessed dynamically. For the implementation, the open source Java Unified Mapping Platform (JUMP) was extended to work as a framework for generalization. Generalization services could be used in different application scenarios, for instance as a middleware component extending a web map service with adaptive zooming or as stand-alone services supporting the production of topographic maps by national mapping agencies. They may also allow the development of a common research platform, where researchers would have access to a common generalization framework.     

Web专题地图发布的研究与实现

本文从网络专题地图的发布框架体系入手,研究了基于XML封装客户端专题地图请求和基于OGC定义的WMS规范构建网络专题地图发布服务等网络专题地图发布的关键技术,并利用ASP.NET从底层实现了网络专题地图发布。     

WMS网络地图服务的应用研究

网络地图服务(WMS)是基于开放地理信息系统协会(OGC)规范的在线地图服务,通过WMS可以实现多源异构地理空间数据的转换和封装,Internet上现在发布了越来越多的WMS服务。本文研究WMS网络地图服务的查找方法和组合使用的方法,用户通过组合网络WMS服务和自定义服务既可满足应用需求,又可达到快速开发应用的目的。     

基于云计算的三维地理空间信息服务的表达

当前云计算的发展已能支持高性能的地理空间服务,比如在数字城市和电子商务等行业。Apache基金支持下的开源软件框架Hadoop,可以用来构建一个云环境的集群用来存储和处理高性能的地理空间数据。开放地理空间联盟(OGC)的Web三维服务(W3DS)就是这样一个很好的三维的地理空间数据服务标准。在标准的云计算环境下将是一个更好的应用示范。基于此,本文研究了OGC的W3DS服务在云计算环境下的实验结果。实验采用Apache的Hadoop框架作为三维地理空间信息服务实验展示的基础。实验结果对展示高性能的三维地理空间信息提供了有价值的参考。     

Cartographic Design and Production in the Internet Era: The Example of Tourist Web Maps

Abstract

Some, but not all, branches of the tourist industry make heavy use of maps. The industry has discovered the marketing potential of the Internet but in many cases has not yet fully exploited the extra potential of web maps compared to the traditional paper maps. Web maps can up-to-date tourist information very well but they have to be carefully designed to take account of the limitations of the medium. To be most effective, web maps should be basically simple and convey sufficient information interactively, on request. The map and symbol design should convey intuitively where and how this interaction can take place. This paper summarizes the typical faults found in tourist web map design and provides suggestions on good design practice.     

GWR与STARMA结合的WMS响应时间时空预测模型

响应时间作为一项非功能性属性,是网络服务性能的重要度量指标。它直接影响了用户的服务体验,并在服务资源选择中扮演重要的角色。响应时间不仅受制于服务自身的软硬件性能,同时还受到用户访问时空分布差异性的影响,具有显著的不确定性,因此如何可靠地预测响应时间是一个难点。选取OGC WMS（web map service）为研究对象,通过全球多地分布式部署的监测系统获取服务响应时间,在分析WMS响应时间与时空因素的关联关系及其变化规律基础上,提出地理加权回归（geographical weighted regression,GWR）与时空自相关移动平均（spatial-temporal auto regressive and moving average,STARMA）相结合的WMS响应时间时空预测模型。该模型综合考虑了用户访问时空分异特征对WMS响应时间的影响,其中GWR部分描述服务响应时间的时空趋势,STARMA部分拟合时空序列局部随机扰动。通过将多个地区监测点不同时刻WMS响应时间的实测数据与模型预测值对比,验证了模型的有效性。实验表明,该模型的预测精度相比经典的平均值法AVG有较大的提升,同时较GWR模型和STARMA模型的精度有一定程度的改善。     

A Spatial Data Infrastructure Approach for the Characterization of New Zealand's Groundwater Systems

The future information needs of stakeholders for hydrogeological and hydro‐climate data management and assessment in New Zealand may be met with an Open Geospatial Consortium (OGC) standards‐compliant publicly accessible web services framework which aims to provide integrated use of groundwater information and environmental observation data in general. The stages of the framework development described in this article are search and discovery as well as data collection and access with (meta)data services, which are developed in a community process. The concept and prototype implementation of OGC‐compliant web services for groundwater and hydro‐climate data include demonstration data services that present multiple distributed datasets of environmental observations. The results also iterate over the stakeholder community process and the refined profile of OGC services for environmental observation data sharing within the New Zealand Spatial Data Infrastructure (SDI) landscape, including datasets from the National Groundwater Monitoring Program and the New Zealand Climate Database along with datasets from affiliated regional councils at regional‐ and sub‐regional scales. With the definition of the New Zealand observation data profile we show that current state‐of‐the‐art standards do not necessarily need to be improved, but that the community has to agree upon how to use these standards in an iterative process.     

Requirements for Next Generation Spatial Data Infrastructures-Standardized Web Based Geoprocessing and Web Service Orchestration

Spatial Data Infrastructures (SDI) have been widely accepted to exchange geospatial data among organizations. Today SDIs main focus lies on the provision of geospatial data in the form of distributed spatial web services, the retrieval through catalogues, and visualization in the form of Web Map Services (WMS). The hypothesis presented in this paper takes SDI's one step further by providing a method to process geodata in an Open Geospatial Consortium (OGC) compliant way into information. Two case studies present the potential of standardized geoprocessing services. In addition, this paper addresses the problem of service chaining by providing a system architecture to implement complex geoprocessing models and workflows based on web services using Web Service Orchestration (WSO). The proposed methods utilize spatial standards provided by OGC, the International Organization for Standardization (ISO) and ‘mainstream IT’ standards provided by the World Wide Web Consortium (W3C) and the Organization for the Advancement of Structured Information Standards (OASIS) to establish a generic web service architecture for providing common geoprocessing capabilities (e.g. spatial algorithms, map algebra, etc.) for usage in SDIs.     

A RESTful proxy and data model for linked sensor data

Abstract

The vision of a Digital Earth calls for more dynamic information systems, new sources of information, and stronger capabilities for their integration. Sensor networks have been identified as a major information source for the Digital Earth, while Semantic Web technologies have been proposed to facilitate integration. So far, sensor data are stored and published using the Observations & Measurements standard of the Open Geospatial Consortium (OGC) as data model. With the advent of Volunteered Geographic Information and the Semantic Sensor Web, work on an ontological model gained importance within Sensor Web Enablement (SWE). In contrast to data models, an ontological approach abstracts from implementation details by focusing on modeling the physical world from the perspective of a particular domain. Ontologies restrict the interpretation of vocabularies toward their intended meaning. The ongoing paradigm shift to Linked Sensor Data complements this attempt. Two questions have to be addressed: (1) how to refer to changing and frequently updated data sets using Uniform Resource Identifiers, and (2) how to establish meaningful links between those data sets, that is, observations, sensors, features of interest, and observed properties? In this paper, we present a Linked Data model and a RESTful proxy for OGC's Sensor Observation Service to improve integration and inter-linkage of observation data for the Digital Earth.     

Web service for biodiversity estimation using remote sensing data

Abstract

This paper presents a technique for the assessment and mapping of land biodiversity by using remote sensing data. The proposed approach uses a fuzzy model that encapsulates different ecological factors influencing biodiversity. We implemented our approach as a web service for the Pre-Black Sea region of the Ukraine.