Development of a method to geographically register airborne scanner imagery through parametric modeling with image-to-image matching.

Paul Albert Pope - 2001
[UMI Proquest Full Citation]

This research developed a modified version of the direct georeferencing method whereby less accurate and temporally coarse trajectory information can be used as input, as compared to the highly accurate and temporally fine trajectory information which is currently required. This new method uses a unique image-to-image matching algorithm based on the comparison of synthetic scan lines to real scan lines to determine corrections to the error-prone input trajectory. The output trajectory can then be used in the direct georeferencing method to correct the airborne scanner imagery to a greater planimetric accuracy than that which would result from using the uncorrected trajectory. This new method is called “parametric modeling with image-to-image matching”, or PMIIM. Sensitivity experiments based on synthetic imagery derived from synthetic trajectories showed that the PMIIM method was able to affect the necessary trajectory corrections. These experiments also provided guidance on the selection of optimal input parameters for using this new approach. The PMIIM method was also used to correct real whiskbroom scanner imagery taken over two study sites exhibiting large differences in land cover. The PMIIM method was successful when applied to imagery collected over the site with heterogeneous land cover, but was far less successful when applied to the imagery collected over the site with more homogeneous land cover. Additionally, the PMIIM method was not able to correct a highly variable trajectory. Ignoring corrections to the roll and pitch parameters of the trajectory drastically reduced the compute time with no loss in planimetric accuracy. This new method has been shown to be a viable technique for geographically registering airborne scanner imagery. However, more research is needed to improve upon the basic approach developed herein.