Detection of Ground Control Points using the SITOGEO- GIS tool to orthorectify Landsat 7 ETM + images

Abstract

Images from the Landsat 7 spacecraft have been widely used in various environmental applications because they are comparatively inexpensive with respect to other satellite data, in addition the panchromatic sensor provides high resolution with a wide coverage area. We present here a orthorectification procedure of Landsat images using the SITOGEO-GIS tool for the GCPs acquisition. Appling this method eighty-five Landsat 7 ETM+ images, covering the entire region of Italy, were orthorectified to the UTM-WGS 84 Geodetic Reference System and organized into a searchable database. Our Landsat images were then compared with the data downloadable from Global Land Cover Facility (GLCF) showing a planimetric discrepancies less than 2 pixels. Moreover this work shows that the best target for GCPs collection is the human-made structures.