Interoperable information model for geovisualization and interaction in XR environments

ABSTRACT

Since the vision of a Digital Earth (DE) was introduced in 1998, geo-browsers seem to have nearly fulfilled this vision. Virtual reality (VR) for visualizing the DE provides an immersive user experience in a mirror world. Location-based augmented reality (AR) browsers have been introduced and provide content according to user and environmental contexts. However, the content models of traditional geo-browsers and AR browsers have very limited interoperability, because they are described in application-specific formats using their domain standards. Each application is vertically integrated from content to application. The Web is an interoperable and open platform, and hundreds of millions of users are already using it to create and share content. To envision DE browsers for cross-reality (XR) environments that concurrently support geovisualization as well as VR, AR, and mixed-reality environments, we propose a DE content model based on Web standards and architecture that provides full interoperability and openness for XR browsers as a first-class citizen of the Web. This is expected to improve the DE content development efficiency by fully using the Web content development environment.     

Spatial video and GIS

GIS elemental unit representations of spatial data are often defined in terms of points, lines and areas. However, another type of spatial data that is becoming frequently captured, but as yet is largely ignored in GIS, is that of video. While digital video recording is a commonly encountered medium in modern society and encompasses many forms, from simple personal camcorders through to sophisticated survey and surveillance systems, its geographical representation in a GIS has not been fully examined or realised. In the majority of cases the video footage is usually captured while the device and/or the objects being viewed are in motion. What is of particular interest is when video streams can be, or have been, associated with spatial data such as location and orientation to create geographically referenced videographic data, which, for simplicity, will be defined as spatial video. Fundamentally, the nature of video is to record space, so when spatial properties can be accurately acquired and associated with this footage, an important geographical element can be considered for integration and analysis within a GIS.

Existing spatial video systems, both commercial and research, are predominantly used in survey or LBS roles and are usually bespoke and application specific. These systems do not model spatial video to any recognised standards that is generalised to be both data and platform independent. They do not support GIS integration and/or analysis from a purely spatial content perspective. A video-image/remote-sensing centric approach prevails where usage options range from simple visualisation interfaces to interactive computer vision systems. What has been largely overlooked is a spatial approach where the inherent geographical extent recorded in each video frame can be modelled and used in a geo-spatial analysis context. While this modelling approach has not been fully realised, it does exist in a GIS form based on Open Geospatial Consortium standards, where the spatial context of video is defined in a structure called a ViewCone. However, a ViewCone only defines a 2D model of the geographical extent of each frame and is restricted to a three-or-five sided polygon representation.

Thus, this article examines the potential of modelling spatial video through the use of elemental data types within GIS; gives some examples of using this approach; describes some problems in using spatial video within GIS; and then demonstrates how these problems are being solved. This is done in three stages: Firstly, a detailed overview of spatial video in its current GIS role is provided – this is achieved through a complete introduction to the distinct elements of spatial video followed by a review of its use in both commercial and academic application areas. Secondly, a brief theoretical overview of an alternative GIS-constrained ViewCone data structure is given that defines a more flexible spatial video model for both 2D and 3D GIS analysis and visualisation. Thirdly, a selective sample of results is presented based on an implementation of this approach being applied to a constrained spatial video data source in a specific study area.     

Spatial video data collection in a post-disaster landscape: The Tuscaloosa Tornado of April 27th 2011

Fine scale disaster response and recovery data suitable for spatial analysis are still relatively rare. This is unfortunate as insight into spatial patterns of recovery could be invaluable in predicting the reestablishment of homes, streets and neighborhoods. The purpose of this paper is to show how fine scale geographic data can be collected in near real-time for the intermediate phase between response and recovery. These data will initially be used to assess the degree of damage (with relation to the Enhanced F scale) while also establishing a baseline for subsequent recovery monitoring. A spatial video system is used to collect data from the post-disaster landscape of Tuscaloosa which was hit by a large tornado in April 2011. This video, once processed, can be viewed within a Geographic Information System which combines street-level images with exact location. These data can be used to support ongoing recovery efforts, while also archiving a dataset suitable for the spatial analysis of the changing post-disaster landscape.     

从新宅居生活看网络虚拟旅游的前景和方向

随着信息化技术和网络技术的快速发展,居家服务系统的越来越完善,不愿或不能出门实现旅游目的的人群越来越庞大。对于数量巨大的不愿或不能外出旅游的"宅居"人群来说,通过网络实现虚拟旅游是最理想的方案。网络虚拟旅游在中国起步晚,但近年来发展快,已表现出产品多样化、技术集成化、需求娱乐化、用户大众化、功能休闲化等特点。目前要解决的主要问题集中在:①3D高清动态仿真效果提质的技术实现问题;②运用AR等新技术优势解决现场体验感不足的问题;③解决景区如何在网络虚拟旅游中受益的问题。未来的网络虚拟旅游方向是:①在线产品越来越真实化和高清化;②客源市场越来越大众化和多元化;③产品内容越来越多样化和分众化;④展示平台越来越普及化和共享化。     

基于GIS的水文地质空间信息系统研究与应用

以区域水文地质信息化与空间分析为目标，以GIS软件ARC／INFO为平台，开发了以水文地质空间数据库为基础，以应用模型体系为支撑的水文地质空间信息系统。以中国西部典型区域的水文地质实际勘查资料为基础，对系统的功能及稳定性进行应用与验证。结果表明：系统具有速度快、准确性与自动化程度高、动态性与可重复性强和可视化程度高等优点，可极大提高水文地质空间分析的有效性、可靠性以及水文地质工作效率，实现基于GIS环境下的地下水预测、模拟、分析与评价的一体化。     

面向个人应用的地理信息集成方案及其关键技术

该文简单回顾地理信息系统应用发展的过程 ,提出面向个人应用的地理信息集成方案和体系结构 ,并对实现此系统的关键技术进行了分析 ,最后探讨了在现有无线通信技术条件下实现此系统的一些问题。     

地理信息系统支持区域土地利用决策的研究

本文以江苏省溧阳县为例,研究地理信息系统技术在区域土地利用多目标规划中的应用,着重探讨地理信息系统支持的区域土地利用决策原理和方法。研究表明,在地理信息系统的支持下,通过单项适宜性评价模型和生产布局决策模型的建立与运行,可以有效地进行研究区合理的土地利用布局和为区域土地管理提供依据。     

GIS在地貌实验与模拟中的作用,困难和对策

目前地貌学的研究方法可归纳为三种：①野外实地考察和记录方法；②定位观测和实地实验方法；③室内实验与模拟方法。地貌学的发展历史表明，地貌实验与模拟是地貌学今后发展的主要方向。     

GIS技术支持下的招远市金矿区崩塌遥感调查

在总结前人研究成果的基础上,全面系统地分析了诱发招远市金矿区崩塌的自然和人为因数,然后运用遥感技术对金矿区遥感图像进行处理,提取诱发崩塌的条件因子,聘请有经验的专家对各项诱发因子进行诊断分析,以此作为判断条件,在G IS技术的支持下对诱发崩塌的条件因子进行空间分析,预测出招远金矿区发生崩塌的危害程度,为防治崩塌提供科学依据。预测结果表明,招远金矿区崩塌有进一步发展的可能,其中,高危险区有36820 m2,中易发区有50 610 m2,低易发区有67 200 m2,需要采取有效措施加以防治。     

探索性空间分析及其与GIS集成模式探讨

探索性空间分析基于让数据说话的理念,可以避免野值或非典型观测值的误导。在对探索性空间分析的基本原理和概念界定的基础上,探讨交互式和动态空间数据分析、地学可视化及可视化空间分布、确认性空间分析、空间数据挖掘等探索性空间分析的主要技术。由于统计分析软件和GIS的数据格式差异很大,直接将二者简单集成存在一定困难,因此切实可行的集成方式是采用对象连接和嵌入(OLE)技术,分别调用统计分析软件的探索性分析功能(或者函数)以及GIS的地图显示和空间分析功能,并进行必要开发,实现二者的集成。最后对探索性空间分析的发展方向进行展望。     

Rs和Gis支持下的自然生态环境评价——以南水北调雅砻江工程区为例

利用TM影像、DEM、温度和降水等气象监测数据,提取了影响自然生态环境的5项重要指标:植被指数,海拔高度,土地覆盖,年均温和降水量。根据这5项环境指标,建立综合自然生态指数模型,并利用该模型对研究区进行环境评价,将研究区的自然环境划分了3级。结果表明该方法能有效地适用于研究区自然生态环境的评价。     

基于GIS的村镇管理信息系统设计与实现

建立村镇管理信息系统对村镇实现科学化、现代化和规范化管理,提高村镇管理和规划决策水平,加速乡村经济发展和社会进步具有重要意义。针对村镇这一聚落地域的信息和管理特点,文章以地理信息系统软件平台为基础,将其与管理信息系统、办公自动化系统有机结合起来,设计了村镇管理信息系统。在论述其设计思想和原则的基础上,详细阐述了基于GIS的村镇管理信息系统的总体设计框架、数据库的建立以及系统所能实现的基本功能。     

Monitoring land changes in an urban area using satellite imagery,GIS and landscape metrics

Monitoring land changes is an important activity in landscape planning and resource management. In this study, we analyze urban land changes in Atlanta metropolitan area through the combined use of satellite imagery, geographic information systems (GIS), and landscape metrics. The study site is a fast-growing large metropolis in the United States, which contains a mosaic of complex landscape types. Our method consisted of two major components: remote sensing-based land classification and GIS-based land change analysis. Specifically, we adopted a stratified image classification strategy combined with a GIS-based spatial reclassification procedure to map land classes from Landsat Thematic Mapper (TM) scenes acquired in two different years. Then, we analyzed the spatial variation and expansion of urban land changes across the entire metropolitan area through post classification change detection and a variety of GIS-based operations. We further examined the size, pattern, and nature of land changes using landscape metrics to examine the size, pattern, and nature of land changes. This study has demonstrated the usefulness of integrating remote sensing with GIS and landscape metrics in land change analysis that allows the characterization of spatial patterns and helps reveal the underlying processes of urban land changes. Our results indicate a transition of urbanization patterns in the study site with a limited outward expansion despite the dominant suburbanization process.     

佛山市旅游信息系统开发

基于地理信息系统和多媒体集成的旅游信息系统开发模式可以融合GIS软件和多媒体软件二者的优点，在实践应用中有巨大的推广应用价值。文中从理论上探讨了GIS库中多媒体信息的链接和表达问题，以关系数据库为核心，把多媒体文件名信息存储在信息系统属库，依靠多媒体字段实现多媒体数据与地理信息系统图形和属性的关联，实现查询的基本概念。以此思路，佛山科技学院GIS技术实验室利用VB进行GIS和多媒体二次开发，成功地完成了佛山旅游信息系统的设计和开发。     

基于GIS的数字地图的应用

文章概述了地理信息系统的特点，分析了基于GIS的数字地图的优势及主要作用，总结了目前数字地图的使用情况和应用效果，探讨了提高数字地图使用效益的有效途经。认为，保证数字地图信息的位置精度和现势性，实现数字地图信息资源共享，扩大地图应用领域和提高地图利用率，增强使用数字地图的先进手段，构造数字地图设计制作与应用的互动平台，开展互联网地图使用情况的调查研究是今后地图应用学研究的重点。     

田野考古地理信息系统研究与建设

基于地理信息系统(GIS)技术建立“田野考古地理信息系统”(FAGIS),为田野考古发掘、研究以及文化遗产保护提供了一种数字化的手段与方法。针对用户“个性化服务”的应用需求,进行了系统柔性平台的框架设计,并分别介绍了基于摄影测量技术的数据采集与处理、考古知识获取与管理、空间决策支持、体视化与虚拟考古环境构建四个主要功能及其研究与实现的途径。     

基于增强现实技术的纸质地图增强表达与交互

近年来随着计算机技术的发展,特别是增强现实技术的出现,使纸质地图的“增强”表达和交互分析成为可能。文章探讨了基于增强现实技术的纸质地图增强表达与交互分析流程方法,认为纸质地图增强表达和交互功能的关键技术在于：纸质地图标识的计算机识别,增强地图的空间匹配方法,增强地图的显示和交互方法;同时通过实验研发了原型系统并予以实现。利用增强现实技术扩展了纸质地图的可视化表达方法,把丰富的地理信息和纸质地图结合起来,打破了传统地图可视化的静态表现形式,提供了丰富的人机交互方式,能增强人对地理信息的多维动态感知能力,也增强补充了地图对现实世界的描述。     

地理信息系统的理论与应用发展

本文重点概述了地理信息系统 30多年来的应用和发展 ,简要地介绍了 GIS软件技术的进步和世纪之交深化地球信息机理、自组织、自相关理论和时空专题高维数据模型以及以 GIS为核心的综合集成技术体系的研究。同时讨论了新世纪信息时代与网络世界在“信息高速公路”、“数字地球”等高新技术迅猛发展进程中 ,对 GIS的深化应用研究 ,应纳入国家信息技术发展计划 ,使 GIS深层次、全方位地服务于国家可持续发展和全球变化的研究。     

基于GIS的山地交通地理信息分析方法与技术

在分析讨论传统山地交通地理信息分析方法弊端的基础上,对基于GIS及GIS-T的山地交通网的建设、管理使用等所需的相关地理信息的分析意义、技术方法等问题进行了探讨。以成都市域的相关数据和MapInfo平台为例,研讨了基于GIS的山地交通地理信息分析基本步骤及山地交通网自身及其主要环境要素的分析内容和方法。研究得到了基于GIS的山地交通地理信息分析方法在可视、实效等方面明显优于传统方法;相关研究的难点及今后进一步深入研究的方向及内容等结论。     

国家土壤信息系统的结构、内容与应用

土壤信息系统建立是当今土壤科学发展阶段的必然要求，全球和有关国家的土壤信息系统在资源评价和模拟等多方面发挥着重要作用。目前在土壤研究不断积累和SOTER研究全面展开的基础上建设我国国家土壤信息系统的工作已经开展。在分析全球和其他国家土壤数据库的基础上，介绍了建设中的我国土壤信息系统的功能和任务设计、基本组成和数据库结构、内容以及研究基础，并举例说明了土壤信息系统在环境模拟中的应用。