Aerotriangulation and DEM/Orthophoto generation from high-resolution still-video imagery: On the potential of digital cameras onboard an aircraft

High-resolution solid-state sensor matrix cameras have found quite some interest among photogrammetrists in the last few years. The limited resolution of such cameras has so far restricted their practical use to applications in digital close-range photogrammetry. Nevertheless, the advantages of the direct acquisition and processing of digital image data in combination with the accuracy potential and the increasing resolution of solid-state sensors have started to make digital cameras interesting for a number of applications in aerial photogrammetry. This paper presents two practical studies on the helicopter-based use of a high-resolution digital still-video camera for digital aerotriangulation and the automatic generation of digital elevation models and orthophotos. Test regions were an alpine village and a landslide area in Switzerland. The current performance and future developments of solid-state matrix sensors are shown, and the advantages and disadvantages of the use of digital cameras in aerial applications are discussed. Using self-calibration techniques, externally verified accuracies of 2 cm for planimetry coordinates and 5 to 6 cm for height coordinates were obtained in digital aerotriangulation using imagery of 1:20,000 scale, and a precision of 0.03 percent of the flying height above ground could be achieved for digital elevation models.