Models of ground surface
elevation, slope, aspect, curvature, roughness, deformation, as well as other
features are gathered together in the term Digital Terrain Model (DTM). DTMs can
be generated from a wide range of technologies such as ground surveying, aerial
and satellite imagery, including both active and passive sensors. Some elevation
derived parameters, such as roughness and slope, can be measured directly using
innovative active sensor technology and smart processing, rather than via
traditional processing of elevation information. Such models are used as part of
a visual interpretation process, and increasingly for computer-assisted analysis
using visualisation technology. There is an ever-increasing demand for DTM
information to be used in the mineral exploration and mining industry, and
consistent pressure from industry to develop models of higher spatial
resolution, higher accuracy, and better overall reliability, regardless of the
world-wide location of interest.
This presentation will survey the
range of techniques available for DTM generation, including active (LIDAR, SAR
interferometry and differential interferometry) and passive (optical or SAR
stereo) methods, as well as interpolation methods (contour or structure
interpolation), and the economic placement of these various techniques in the
local and regional context. The research issue oftrue-ground elevation models
and slopes is also addressed, using LIDAR and SAR polarimetry as signpost
technologies. Particular emphasis will be given to the strengths and limitations
of new data sources that will, over the next few years, make the acquisition of
elevation models of remote regions of the world inexpensive and relatively
accurate.