DEM/DTM Generation

Digital Elevation Model is the representation of earth’s topography using digital methods. Digital elevation model is also called as digital terrain model (DTM). DEMs or DTMs can be represented as original maps, square grids or irregular network of triangles.
The main application of DEM are,

• GIS Services
• Surface Analysis
• Orthophoto generation
• Global Positioning System
• Aerial Photography
• Bare Earth Surface Model
• Base Mapping
• 3D Visualization

To get more information check this link DEM/DTM generation