Landsat imagery has been used on two road investigations in the Sudan to provide information on the four main factors that affect route location, i.e. soil strength, earthworks, drainage requirements and construction materials. The interpretation techniques included the production and enhancement of colour composites in a purpose built additive viewer which was also used for examining photographically prepared density slices of infrared 'band 7' imagery. The work in the Sudan, together with a review outlining the advantages gained by repeated observations of the earth from space, is used to define the main techniques that can be employed and to identify the major areas where satellite imagery could assist the highway engineer. It is concluded that the present generation of imagery is most suited for the planning and feasibility stages of engineering survey for road projects, such as the preparation of regional maps and inventories of terrain characteristics or reconnaissance studies involving decisions on route location. (Author/publisher)
Samenvatting