Georeferencing and Orthoimage Generation from Long Strips of ALOS Imagery

Precise georeferencing is one of the prerequisites for orthoimage generation from high-resolution satellite imagery. This involves the precise estimation of the parameters of the sensor model that relate the object coordinate system to the row and column indices of the original image and requires the availability of a small number of ground control points (GCPs) that have to be visible in each scene. In this paper, it is shown how the number of GCPs required for the precise georeferencing of ALOS imagery can be reduced by up to 90% using a generic pushbroom sensor model and strip adjustment. Using this technique, the productivity in orthoimage generation can be increased by 300% while still achieving an accuracy of 1 pixel or better.