ABSTRACT
The satellites used on the CORONA missions carried 2 cameras on board, which enabled the recording of stereo images of the earth’s surface. During the operational phase of the satellites, panchromatic images were recorded from many regions of the earth at a flight height of 150 km. The resulting data have been available to the public since 1995 and cost 18 US$ per strip. Thus these data are not only affordable for projects with limited budgets, but also are a very useful source in regions where surface information is hard to get or even not available. In this paper two methods are described which transform photographic information into digital format and handle the data with software tools of digital photogrammetry. The first method is applied by photographic enlargement with a scan of the photos; the second approach is to perform a high quality scan of the strips directly. CORONA image strips have no fiducial marks, so this leads to a non metric approach. Techniques of modern photogrammetry allow, nevertheless handling the data and to derive a high resolution digital elevation model. Therefore, during a field campaign it is essential to take Ground Control Points (GCPs) with high accuracy. A LEICA 300 Differential Global Positioning System (DGPS) is used. These points are needed to calculate the external orientation of the Digital Elevation Model (DEM). The achieved accuracy in z direction is in the order of 20 meters relatively, and in x and y direction in the order of 9 metres.
