Source of DTM data	Data Capturing method used	DTM accuracy	Areal coverage	Typical applications
Ground survey	Total or semi-total station	Very high	Limited to specific sites	Small area site Planning and design
Photogrammetric measurements	Stereoplotting Machine (with or without correlators	High (if from spot heights) Lower (if from contours)	Large area projects,especially in rough terrain	Large engineering projects:dams reservoirs, roads, open-cast mines Nationwide especially in association with orthophotographs
Cartographic (existing topographic maps)	Either: Manual digitizing Semi-automatic Line following Fully automatic raster scanning	Low: derived from contours on medium and small scale topographic maps	Nationwide at small scales	Aircraft simulators, Landscape Visualization, landform Representation, military battlefield simulation