GIS and Satellite Image Analysis Using QGIS（No.2 Basic Functions-1）

QGIS as a Free and Open-Source Systems (FOSS) provides various functions. The basic functions to analyze the terrain of raster elevation data are explained for slope, aspect, shadow, relief, and ruggedness of ground surface. The computational duration is in short. The slope can be calculated in metric scale, so that you need to reproject in latitudelongitude to UTM for the same units of metric of elevation. The extraction of contour as the representative transformation from the raster to vector provides to display the extracted values in a certain interval on GIS.