A generic model for along-track stereo sensors using rigorous orbit mechanics

In this paper a generic, rigorous sensor model for high-resolution optical satellite sensors with along-track stereoscopic capabilities is introduced. 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, trying to find 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. 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 assumption is that Keplerian 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. 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 and using the metadata information, with acceptable accuracy. The model is evaluated using SPOT5-HRS imagery with precision close to pixel size. Moreover, the accuracy of the along-track model is compared with the accuracy of single image sensor model.