Calibration and Georeferencing of Aerial Digital Cameras

The conventional determination of the orientation parameters of photogrammetric images by aero-triangulation is increasingly complemented or even replaced by direct observations obtained from GPS and inertial (IMU) systems. For including these measurements in the image data processing a procedure was developed as well as the design principles of a calibration equipment formulated with the aim of op-timally accomplishing these tasks with a minimum of costs. The orientation parameters directly observed with IMU and GPS sensors are corrupted by systematic er-rors that are caused by error parameters of these sensors. In order to detect the sources of the errors and to eliminate the ensuing errors from the sensor data, homologous image points of object points of the terrain are determined that are recorded during a mission from at least three different camera positions. These camera coordinates together with IMU and GPS data are subjected to a least squares adjustment, which yields the following results: • the orientation parameters at every recorded instant during the mission; • offset data; • systematic errors of the measurement equipment; • precision of these data. The algorithms of this procedure have been generated and coded both for model simulations and for rou-tine services