期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2004
卷号：XXXV Part B2
页码：365-370
出版社：Copernicus Publications
摘要：With the changing status of GIS from desktop to distributed environment, geographic information is more often required to transmit over networks. As geospatial data is in essence of huge volume and complicated but the bandwidth of a network is limited, it is of great importance for map-QoS to transfer data as less as possible. This paper discusses this problem from the view of information theory and proposes a novel approach of information measurement for minimizing of geospatial data size while delivering map information constantly. This paper starts from a discussion of map-QoS concerning map as a media carrying geographic information. Either on various display mechanisms or on paper-alike media, geographic information is transformed to map, an image to stimulate visual sentience of human being. However, visual sentience of human being has only limited spatial and frequency resolutions. Map with resolution approaching or higher than this limit increases little or even decreases the amount of information contained. Display mechanisms and paper-alike media also have their maximum spatial and frequency resolutions. It is impossible for a map to display more data than its capacity. For map-QoS, the size of geospatial needed is the minimum to reach this capacity. Based upon above understanding, this paper proposed a raster-based measurement of geographic information contained in a map. A study of the relationship between data size and map information by this measurement reveals that this is usually a mono-modal curve with a single peak
关键词：Internet/Web; GIS; Information Measurement; Mapping; Visualization; Services
