Simulation of Three-line CCD Satellite Images from Given Orthoimage and DEM

Though IKONOS has been flying in the space,there are few chances to get its original images.But in some cases,we need original three-line CCD images to do tests about along-track stereo.In our study,Kratky's rigorous model is adopted,with earth rotation taken into account.With simulated images,we try to investigate several aspects from orientation,epipolar images,and the Earth rotation effects on along-track stereo.With DEM and orthoimage generated from SPOT image of the Three Gorges area by VirtuoZo,several experiments have been done.Some conclusions can be drawn:①In order to get large overlap of fore-look and aft-look image,side-look angle must be considered for them,and the angle should be adjusted according to the latitude of satellite position;②The polynomial fits for SPOT images'epipolar relation does not fit along-track stereo any longer,but increasing items of the polynomial can increase the fitting accuracy significantly;③The epipolar accuracy of Baltsavias'method depends on the accuracy of orientation parameter of images;④Systematic errors may exist in epipolar images generated by Baltsavias'method,which can be removed with linear fitting.