Abstract: A method and an apparatus are disclosed that extract digital elevation data from a pair of stereo images with two corresponding sets of airborne control data associated with each image of the stereo image pair. Point and edge features are identified from the stereo image pair, projected from respective camera stations of the stereo images onto a horizontal projection plane using respective set of airborne control dam including respective positions of a camera station, the interior orientation and calibration data of the camera, respective roll angles, respective pitch angles, respective yaw angles of each image, and respective flight bearing angles. The space coordinate of each projection are compared in object space to obtain an object-space parallax. The topographic elevation of each feature is derived from said object-space parallax, a base length, and the altitude of a camera station autonomously to eliminate the need for stereoscopic viewing device or ground control data.