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ABSTRACT:Dynamic camera systems with moving parts are difficult to handle in photogrammetric workflow, because it is not ensured that the dynamics are constant over the recording period. Minimum changes of the camera's orientation greatly influence the projection of oblique images. In this publication these effects -originating from the kinematic chain of a dynamic camera system -are analysed and validated. A member of the Modular Airborne Camera System family -MACS-TumbleCam -consisting of a vertical viewing and a tumbling oblique camera was used for this investigation. Focus is on dynamic geometric modeling and the stability of the kinematic chain. To validate the experimental findings, the determined parameters are applied to the exterior orientation of an actual aerial image acquisition campaign using MACS-TumbleCam. The quality of the parameters is sufficient for direct georeferencing of oblique image data from the orientation information of a synchronously captured vertical image dataset. Relative accuracy for the oblique data set ranges from 1.5 pixels when using all images of the image block to 0.3 pixels when using only adjacent images.

Automated processes for building reconstruction including roof-and façade structures with accuracies better than 0.5 m have not been developed yet. This paper introduces a conceptual approach to derive 3D building edges automatically from oblique aerial imagery. A sub-pixel accurate version of the Canny algorithm is used for detection and segmentation of line segments found on seven oblique true orthomosaics (TOM) mapping a scene from different cardinal directions. With respect to the properties of oblique photogrammetric products and the characteristics of their derivation, all detected line segments are weighted based on their individual camera-target path. An adjustment approach is implemented, which adjusts redundant line segments that are found in several oblique TOM. A validation of the adjustment is done by using tacheometrically measured reference points. On average the approach yields in accuracies of 30 to 35 cm in X, Y and Z.