Recognition and Measurement of Marine Topography for Sounding Generalization in Digital Nautical Chart

Generalization is a comprehensive process. It is not simply a question of an algorithm, such as simplification, selection, displacement, and so on. Only after geometric shapes and topological properties have been understood fully, can a sound and automated generalization process be possible. This article proposes a new theoretical model for sounding generalization in digital nautical charts. First, with the aid of Delaunay triangulation, a tree structure is introduced for a hierarchical representation of the marine topography. Then, an analytical algorithm for the recognition and the measurement of the marine topography is developed through the use of the tree structure. Finally, all of the techniques mentioned above are integrated into a model for sounding generalization, of which results are illustrated with the aid of several examples.