Technical note an assessment of the geometric accuracy of remotely-sensed images

Raw digital images cannot be used as maps because they contain geometric distortions which stem from the image acquisition process. To supply the same geometric integrity as a map, original raw images must be geometrically corrected and the distortions, such as variations in altitude, and earth curvature, must be compensated for. In this Technical Note, the geometric accuracy of a SPOT P image was evaluated by comparing a ground-based reference area, with areas calculated from the image. The areas were calculated using four different methods.