A New CCD-based Technique for the Calibration of Leveling Rods

At the Geodetic Laboratory at the Technical University Munich (TUM) there are the most advanced calibrators for precise leveling invar rods. They are equipped with a laser interferometer as a reference, and with an CCD array camera to detect the bars on the rod scales. The technical setup, which was initially developed at the Chair of Geodesy at the TUM and is now state-of-the-art, is explained in this article. Further on, the concept of image acquisition and detection of graduation bar edges is shown.