Second, we describe the main types of DEM grids, viz.
We consider general principles of DEM production through conventional ground topographic surveys, kinematic global navigation satellite system techniques, stereophotogrammetry, structure-from-motion techniques, laser altimetry, synthetic aperture radar techniques, echo sounding, satellite radar altimetry, airborne optical sensing of bathymetry, soil and geological core drilling, three-dimensional seismic surveys, ice penetrating radio-echo sounding, and the digitizing of contours, as well as the fusion of elevation data from different sources. In this chapter, we first present a brief review of techniques used to produce digital elevation models (DEMs). Florinsky, in Digital Terrain Analysis in Soil Science and Geology (Second Edition), 2016 Abstract The selection of a technique to produce a DEM for soil and geological research depends on several factors, such as the size of the study area, required accuracy and resolution of the DEM, accuracy and resolution of other maps and materials as well as the cost of the DEM generation. DEMs of stratigraphic surfaces are also compiled using data obtained by various techniques, such as 3D seismic survey, geological boring, and other available geological sources. DEMs can be generated by various field, remote, and laboratory techniques: conventional topographic surveys, kinematic GPS surveys, analogue, radar techniques, laser surveys, and digitizing of contours. Among DTMs are DEMs, digital models of slope gradient, horizontal curvatures, catchment area, and other topographic attributes. A DTM is a two-dimensional discrete function of a morphometric variable, which defines the topographic surface as a set of values measured or computed at the grid nodes. This chapter highlights the digital elevation models (DEMs), their generation, grid types, resolution, and interpolation. Florinsky, in Digital Terrain Analysis in Soil Science and Geology, 2012 Publisher Summary