Automatic matching and generation of orthophotos from airborne and spaceborne line scanner images

Caused by the turbulent atmosphere, the original airborne line scanner images are partially strongly deformed against normal case images and the ground coordinate system. An automatic matching requires a special program which can use the available orientation information from a combination of relative kinematic GPS-positioning and inertial measurement system (IMU). Another possibility is the rectification of the line scanner images to a chosen height level using the camera orientation for every single line. Such rectified images are displaced by the actual ground height and the view direction – especially in the case of inclined lines. The geometry is very close to the geometry of stereo orthophotos, also a stereo view is possible. With these rectified images an automatic image matching is possible by programs based on the region growing method like program DPCOR and with a special program the ground coordinates of digital elevation models (DEM) can be computed with the matched corresponding pixel positions of the rectification’s and the sensor orientation. Exactly the same situation is given by the GEO-product of IKONOS-images. They are also rectified to a chosen height level. For the ortho-rectification of IKONOS GEO-products it is not necessary to use the full sensor orientation, the available nominal collection azimuth and elevation is totally sufficient. If control points in different height levels are available, also this information is not required for an optimal geometric correction shown at an example in