Optimum Sampling for Digital Terrain Modelling

The investigation addresses three main issues: The first concerns a study of the terrain relief classification for the purpose of composite sampling. The second issue concerns quality assessment models that are used to assess the quality of representa~ion pf ideal geometric primitives and of real terrain relief representation. The third issue concerns the performance of composite sampling when applied to real terrain relief. In order to test the rules drawn from idealised geometric primitives on real terrain relief, two different terrain models were selected. First the skeleton information was sampled selectively, then Composite sampling was carried out. Finally, the quality was assessed implementing the quality assessment model. The analysis of the test res~lts provides a feedback for optimizing the procedure for Composite Sampling. KEY YORDS: Selective sampling, progressive sampling, skeleton information, filling information, composed transfer function, break line, peripheral line, rule base.