Image Orientation by Combined (A)AT with GPS and IMU

One precondition for direct sensor orientation with GPS and IMU is the correct sensor calibration. The related parameters as well as the relation between the IMU and the aerial camera (boresight misalignment) have to be determined by conventional bundle block adjustment. During this process a camera self calibration (focal length, principal point, additional parameters etc.) may be performed under operational conditions. To achieve the full accuracy potential of direct sensor orientation, the compensation of systematic errors with the correct mathematical model and an optimum number of parameters for sensor calibration is required. A series of tests was conducted and showed the good accuracy potential of direct GPS/IMU sensor orientation. First investigations showed also problems with y-parallaxes of stereo models based on direct sensor orientation. Future developments in GPS and IMU sensors and data processing may reduce this problem. Just now we do need another save solution. A promising one is the integration of GPS/IMU and (automatic) aerial triangulation (AAT) into bundle block adjustment, also called integrated sensor orientation. This paper presents the sensor calibration based on data from test flights in large image scales. Furthermore it demonstrates the accuracy potential at independent check points in object and in image space for direct and integrated sensor orientation.