CALIBRATION OF CAMERA SYSTEMS

Multiple camera systems including combinations of vertical and oblique images like used by Pictometry and Multivision are becoming popular very fast. The image combinations easily can be used for interpretation and also for metric purposes. In most cases the orientation is based on direct sensor orientation, using inertial measurement units and relative kinematic GPS-positioning. Usually this will be done not with the precision, possible for standard photogrammetric projects, but the geometric precision can be improved by satisfying system calibration. The system calibration includes the calibration of the sub-cameras and the geometric relation of the oblique sub-cameras to the vertical reference camera together with the boresite misalignment. Supported by the direct sensor orientation, also the inner orientation can be improved. The individual camera geometry can be determined by bundle block adjustment with self calibration. This allows also determination of the relation of the sub-cameras to each other. The procedure, computational steps, results and limitations are described.