An Intensive Comparison of Triangulated Irregular Networks (TINs) and Digital Elevation Models (DEMs)

This work presents the results of an intensive examination of two competing digital terrain models: regular gridded digital elevation models (DEMs) and triangulated irregular networks (TINs). The importance of representing a surface as accurately as possible in a given amount of space or time is presented. The backgrounds of the DEM and TIN models are reviewed, including their origins, constructions, advantages and disadvantages. Some of the numerous possible applications of digital terrain models are described. A study to compare the two models over a wide variety of terrains is presented and described in detail. Twenty-five 7.5- minute study areas are carefully selected to be representative of the terrains found in the United Slates. Eight different terrain models — two DEMs and six TINs — are constructed: all are based, directly or indirectly, on the digitized contours found in the USGS DLC files. The gridded models are created with the latest USGS procedure, CTOG, which interpolates a grid from digiti...