THE POTENTIALS OF SATELLITE IMAGES FOR MAP UPDATING WITH EMPHASIZES ON EGYPT SAT-1 IMAGES

Abstract

The lack of adequate maps is one of the critical issues to be handled in developing countries. The main problem is the rapid development of urban areas, so that maps are out of date very fast. Consequently, nearly all these maps have to be revised and updated as soon as possible. Recently, due to the improvement in satellite technology, remote sensing data is applied for mapping and map updating at different scales. On April 17, 2007 the first Egyptian earth observation satellite Egypt Sat-1 was launched. The available images from Egypt Sat-1 satellite provides valuable source of remote sensing data in Egypt. This paper aims to evaluate the potential of Egypt Sat-1 images versus other satellite images for maps updating. Data used in this study are satellite images from Egypt Sat-1, SPOT 4, IKONOS and topographic map at scale 1:25,000. The methodology focuses on visual comparison of the images over the test area for specific features such as roads, railways, watercourses and boundaries of urban areas. After that an investigation is carried out for the potential of the information content in Egypt Sat-1 images, for updating 1:25,000 map. The results of these evaluations show that Egypt Sat-1 images, from the point of geometric accuracy, have the capability of 1:25,000 scale maps revision. Also, from the point of information content, it have the capability of revision of the main features such as building blocks, roads and vegetation cover. Revision of other objects in Egyptian 1:25,000 scale maps that are problematic in their identification and extraction from Egypt Sat-1 images can be completed using other mapping methods.