TABLE OF CONTENTS In the previous two chapters, we discussed possible alternatives for retrieving the continuous surface of the Earth from discrete samples as represented by the elevations at the reference points. In this chapter, we will discuss other aspects of DTM manipulation; namely, DTM generalization and quality control. DTM generalization is a filtering process, where the elevation data is reduced to produce a subset of the original data while maintaining key surface characteristics. The quality control investigates the factors that might affect the accuracy of the DTM data as well as the quantitative measures for assessing that accuracy. The quality control analysis starts by investigating error sources in the collected elevation data from different acquisition systems. This discussion will be followed by an outline of several techniques for comparing overlapping elevation data, which might have been captured at different times by the same or different acquisition systems, for quality control purposes.
DTM data is usually used with other data and/or information to provide new products and information. For example, DTM data is combined with aerial and space imagery to produce orthophotos of the area in question. Also, DTM data can be integrated with vegetation cover, soil type, and meteorological conditions to provide information regarding the potential of fire, landslides, or flooding. To achieve the aforementioned objectives, DTM and other data sources are usually incorporated in a GIS database (Bossler et al., 2002). The individual components of a GIS database are available at different scales and are usually...
