Digital Cartography Laboratory (ZS1001)

THe mapo is an ancient means of communication for human beings. A map is a kind of symbolized representation of geographical features and/or phenomena in graphical form. The effectiveness of a map relies on the effectiveness of overall design, map symbols and map legends. Systematics investigations have been carried out into the effectiveness of map symbols and design principles of effectiveness map legends. Effectiveness of symbols has been systematically studied and rules for legend design developed.

Maps are produced to scale. Maps at different scales show different levels of detail and are employed for different applications. In mapping practice, smaller scale maps are normally derived from larger scale maps by a process called "map generalization" to avoid new field survey which is time-consumming and expensive. To automate the map generalization process has been the dream of cartographers for years. To do so, the process must be made objective to so as to facilitate the development of mathematical models and algoritms for geometric transformation from larger-scale to smaller-scale.

Topographic maps are intended to faithfully represent the real world and thus contain various types of detailed information. However, for many purposes (e.g. personal navigation), too much detailed information makes the map appear noisy, especially on smaller displays. Therefore, nowadays, usability-centered maps have become popular. These maps may have violated one or more principles of map making, thus called map-alike representation.

Each national mapping agency produces maps at many scales. Nowadays updating and maintenance of topographic maps at very many scales has become a difficult task. In updating maps, a two-step procedure consisting of (i) a detection of changes and then(ii) the propagation of these changes (to smaller-scale maps) is still the main approach. Automated techniques have been developed based on this approach.

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