What is the role of the digital terrain model (DTM) today?
” A digital terrain model (DTM) is different than a digital elevation model (DEM), the first representating a continuous surface as if all the objects are removed – a bare surface. Alternatively, a DEM represents a surface where objects are included in the surface measurement. It is possible to process DEM, so they are DTM. For all intents and purposes a DTM represents the earth’s land surface. The processing involved to turn a DEM into a DTM means added cost to a project. The obvious question is, why use a DTM instead in the first place? So let’s start there. Houses come and go, bridges come and go and trees just grow and die. Skyscraper’s are built, and even false covering can obscure the land beneath. For these reasons, a DTM represents the earth’s true surface, regardless of all of these objects and their changing natures. Surfaces are usually interpolated. This recognizes the principle that not all points on the earth’s surface are actively measured and determined, thus they have
