Abstract: A photogrammetric plotting apparatus is provided. The apparatus comprises an optical system means for viewing by an operator of an image of a first stereomodel derived from a pair of stereoscopically related photograms. The apparatus is further comprised of an operator controlled means for effecting stereomodel exploring motions relative to the photograms, and a tracing or display device. A means is provided for converting the exploring motions into plotting motions for the tracing or display device. A means is additionally provided for scanning image data of a second model to produce an image of the second model. Means is provided for conveying the image of the second model to the optical system. The optical system includes a means for superimposing the image of the second model on the image of the first stereomodel for simultaneous viewing by the operator.