DEM LEVELLING FOR MOSAICIING

Abstract

Digital Elevation Model finds use in wide range of applications. Often the study area in such applications is very large, which needs the mosaicking of the smaller DEM tiles. When different DEM tiles are mosaicked together then systematic errors such as vertical offset and tilt between the DEM tiles can produce visible discontinuities along the borders of the overlapping areas. The standard mosaicking procedures reduces just the inconsistencies at the boundaries of the areas of overlap; the remaining portion of DEM tiles is left uncorrected. The method used in the dissertation tries to use the cell values present in the overlap region to reduce the vertical offsets and the tilt present in the DEM tiles. By reducing these differences the DEM tiles are oriented or levelled with respect to each other. After processing the DEM by using the proposed methodology the DEM tiles can be subsequently used for preparing mosaic.