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A scheme for automatically generating GCPs and hence
performingorthographic correction for airborne scanner imagery
was developed.The consists of three parts. The first part is a
ray tracing algorithm, which produces orthographic images using
digital elevation model (DEM), scanner characteristics, and
flight parameters. The second part is a GCP generation
algorithm, which bases on feature point extraction from a
reference image and image matching with respect to its
counterpart, i.e., and a working image. The third part consists
of producing flight parameters from DEM, scanner
characteristics, and GCPs using least squares fitting. Those
three parts are integrated in an iterative way to improve the
accuracy and to minimize the manual operation in control potion
marking. Experimental results indicate that the accuracy may
reach 20 METER in the image scale for hilly area and 8 meter for
planny area.
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