Calibration of CCD sensors mounted on geodetic measuring systems

If the eyepiece of a total station is replaced with a CCD sensor, the most important task is to calibrate the instrument. Calibration establishes a connection between the readings on the horizontal and vertical circles of the total station and the readings in the coordinate system of the CCD sensor. Our calibration method uses a collimator in a few meters distance, which serves as a target at infinity during the calibration. We tested the calibration using a QDaedalus astrogeodetic measuring system. The optimal number of calibration measurements, the optimal raster size, and the temperature dependence of the measurements were investigated.