GENERATION OF DTM FROM IRS-PAN DATA

Abstract

Digital Terrain Model (DTM) is a representation of spatial characteristics of terrain in discrete or functional form. It may be defined as an expression of land or a conceptual framework required for a computerized terrain information system (Singh, 1988). In other words, the representation of terrain data in digital form is called a Digital Terrain Model. The terrain data or characteristics may pertain to various themes such as elevation, slope, soil type, land use etc. DTM plays an important role in engineering projects such as planning of roads, rail roads, channels and dams or for calculation of mass (soil) movements for bigger working areas. The conventional method of collecting the elevation data is from topographical maps available at 1:50000 or 1:25000 scales. The contour interval is approximately 20m to 10m. These maps are generally updated after a long period of time and also the contour interval is insufficient for many engineering problems. Therefore for getting updated information and also for higher height accuracy, ground survey for a local area on larger scale is done.