Registration of Terrestrial Photogrammetric Data Using Natural Surfaces as Control

We present a model for the alignment of image sets using topographic data as control information. Traditional photogrammetric practices are point-based and require well-measured and clearly marked entities within the scene; for repeated measurement, their demarcation should also be durable. Nonetheless, placement of photogrammetric control points oftentimes cannot be readily implemented within the area for documentation. In many of those cases, some form of topographic model, either coarse or fine, exists or can be readily established. This topographic description provides a broad and markerless coverage of control information, which, if modeled appropriately, can substitute the use of a control-point network in the alignment process. We present in this paper a registration model for terrestrial images based on surfaces as control information. The paper addresses both the problem of acquiring mutual corresponding entities and registration based on varying resolutions. The application of the proposed approach is demonstrated on a mapping of an archeological site and for registration of a set of terrestrial images of an open, unstructured scene using airborne laser scanning data. Results show both the applicability of such a model and that estimation comparable in quality to point based observations can be achieved.