POTENTIAL OF USING HIGH RESOLUTION SATELLITE IMAGES FOR MAPPING APPLICATIONS

Abstract

Cities and villages in Egypt are subjected to rapid growth. Growth canbe beneficial economically, but it also has significant effects on theenvironment, and if it is left unchecked can have negative impacts. Rapidpopulation increase led to replace agriculture land by buildings, roadsand highways. The changes are in particularly harmful when urbanexpansion occurs against surrounding agricultural areas. So theexpansion of cities and villages must be monitored. Recent developmentsin remote sensing enable us to use high resolution satellite images fordifferent purposes. One of the main application fields for remotelysensed data is the large-scale topographic mapping and map revisions,for which it is necessary to detect and extract features from suchimagery. The high resolution space images available now from IKONOSand Quick Bird do have a resolution which is partially in competition toaerial images. This paper presents an evaluation of using IKONOSsatellite images for large scale mapping purpose. This evaluation hastwo elements, the first is geometric potential and the second is theinformation contents. The results of this study show that correctingIKONOS imagery using one or two Ground Control Points (GCPs) givesabout 1.6m horizontal accuracy, higher accuracy can be obtained usingmore GCPs. The feature extraction is performed by manual on screendigitizing. The results are verified against a 1:25000 topographic map,features such as roads and canals can be extracted with about 70-99%accuracy.