A generic rigorous model for a long track stereo satellite sensors
The aim of this thesis is to develop a generic rigorous sensor model for high resolution optical satellite sensors, with along track stereoscopic capabilities, in order to orientate directly and simultaneously all the along track stereo images. In other words, the idea is to determine the orbit of the satellite platform covering the time acquisition of all images, using satellite photogrammetry in combination with astrodynamics, thus finding common exterior orientation parameters for all images directly or indirectly. As a result, the number of unknown parameters is reduced and also the correlation between them, thus giving a more stable solution. Moreover, the simultaneous solution extends the narrow field of view of each satellite image because all along track images are treated as one iconic image, with the field of view equal to the angle between the first and the last image. Great effort is made in order to define the essential forces which are involved in the acquisition of the pushbroom images, according to the needed accuracy and the data provided. The fundamental assumptions is that Kepler motion is maintained along the acquisition time of all the along track images. Various versions of the model are developed, based on different orbit determination-propagation methods. The first one, based on the Kepler problem (orbit propagation), can be used for more than two along track images. The second one is based on Gauss-Lambert method which can be used only for two along track images like SPOT-HRS and TERRA-ASTER. The final one is based on Herrick-Gibbs method which is combined with the Gauss-Lambert method in order to be used in the case of more than two along track images. An accuracy assessment is made of the above different orbit determination-propagation methods. It is possible to extract the exterior orientation of all images together directly, without Ground Control Points using the metadata information, with accepted accuracy. The model is evaluated using TERRA-ASTER and SPOT5-HRS imagery with precision close to pixel size. Finally the accuracy of the along track model is compared with the accuracy of single image sensor model and of a commercial sensor model (Leica Photogrammetry Suite).