How to valorise aerial photos in GIS?

Abstract

The fast progress of microcomputers has made available new mass storage capacities and new techniques of image processing. Users of aerial photographs have now access to friendly softwares, allowing the integration of these images in a digital environment. These tools allow to orthorectify aerial photographs to integrate them in Geographical Information Systems. This technical note provides some technical background concerning orthorectification and the software, hardware and data necessary to accomplish this task, and presents a study based on this technique aimed at following forest cover evolution at the watershed scale.