Digital terrain model computation from contour lines : How to derive quality information from artifact analysis

Digital Terrain Models constructed from contour lines often contain artifacts originating from their construction from irregularly spaced height measurements. We evaluate and illustrate these artifacts and their impact on terrain parameters. We provide algorithms to correct them as much as possible, and propose a methodology to predict areas where uncertainty still remains because of these artifacts. The analysis of these artifacts enables us to derive qualitative parameters such as "likely over-estimated", "likely underestimated", and "with no significant bias" on the DTM. Our method provides a qualitative description of local uncertainty, which is often more relevant for geographical applications than global quality parameters.