摘要:Geographic Hypermedia (GH) is a rich and interactive map document with geo-tagged graphics, sound and video elements. A Geographic Hypermedia System (GHS) is designed to manage, query, display and explore GH resources. Recognizing emerging geo-tagged videos and measurable images as valuable geographic data resources, this paper aims to design a web-based GHS using web mapping, geoprocessing, video streaming and XMLhttp services. The concept, data model, system design and implementation of this GHS are discussed in detail. Geo-tagged videos are modeled as temporal, spatial and metadata entities such as video clip, video path and frame-based descriptions. Similarly, geo-tagged stereo video and derived data are modeled as interrelated entities: original video, rectified video, stereo video, video path, frame-based description and measurable image (rectified and disparity image with baseline, interior and exterior parameters). The entity data are organized into video files, GIS layers with linear referencing and XML documents for web publishing. These data can be integrated in HTML pages or used as Rich Internet Applications (RIA) using standard web technologies such as the AJAX, ASP.NET and RIA frameworks. An SOA-based GHS is designed using four types of web services: ArcGIS Server 9.3 web mapping and geoprocessing services, Flash FMS 3.0 video streaming services and GeoRSS XMLhttp services. GHS applications in road facility management and campus hypermapping indicate that the GH data models and technical solutions introduced in this paper are useful and flexible enough for wider deployment as a GHS.
关键词:geographic hypermedia system; data model; web service; system design