Abstract: A photogrammetric stereoplotter using a stereoscopic binocular unit (1) to provide an image of spatially separated masters (4,5) and including a cursor (6) providing X Y coordinates and measuring marks providing Z coordinates in which the X Y Z coordinates are fed through a stereogrammetric unit (7) to a computer (8) with a display and/or printer (12,13) and an interface (14) to a display tube (16) and through an optic train (18) to at least one side of the binocular unit (1), and including a topographic keyboard unit (10) arranged to feed information to record the trace, and optionally a voice recognition unit (20) with two-way communication between operator and computer (8), and means in the computer (8) whereby model coordinates from the said binocular unit (1) are changed to image coordinates by the computer (8) to achieve precise superimposition of the trace image to eliminate visual disturbance.