An apparatus for use in photogrammetry is disclosed having two spaced-apart parallel scanning zones to which the photographs of a stereoscopic pair of photographs are mounted. A carriage mounted optical scanning system is provided for scanning the two scanning zones and for projecting images of the respective zones to a binocular viewing system, and a secondary optical system is provided, preferably on the carriage, for superimposing reference marks on the projected images. The scanning system is arranged in such a manner that simultaneous scanning of the two scanning zones can be effected in a first direction parallel to the scanning zones, and independent scanning of the two scanning zones can be effected in a second direction which is parallel to the scanning zones and orthogonal to the first direction. Also, the apparatus is adapted to permit relative scanning of the two scanning zones in the first direction or for optically moving the reference marks relative to one another in the first direction.

A cartographic apparatus for determination of the elevations of features and heights of objects from stereoscopic images of complementing input records includes a parallax bar and movable reticles for generating a floating mark over points of interest in the records. The apparatus also includes a microprocessor to compute compensation factors based on values determined during initial set up and means responsive to those factors to compensate automatically for y parallax and for errors in x parallax difference as the floating mark is moved and to compute automatically object heights and feature elevations.

A method for automatically registering an image pair having a common coverage area, wherein a pair of image data sets, each representing an image of an image pair, are processed to generate initial dewarping coefficients for the image data sets. The translational offset between the images is estimated using a phase correlation process. Next, the common coverage area of the data image sets is determined by finding the vertices defining the limits of the common coverage area. Conjugate point pairs are extracted from the common coverage area by defining a series of block and subblock grids and defining the center point of the grid as a conjugate point location. The determined conjugate point sets are used to generate geometrically corrected registered dewarping coefficients and the image data sets are resampled using the registered dewarping coefficients to generate a registered image pair.