Estimating geometrical transform parameters for affine-transform-base geometrical corrections

The geometrical transform parameters included in the ancillary file of the system-corrected Landsat TM image, such as a translation, a rotation angle and a scaling, may contain errors. Therefore, it sometimes occurs that the orthoimage obtained by the affine transform is not desirable. In order to overcome this problem, Iikura proposed the method that orthorectifies the satellite image with digital elevation model (DEM) and optimizes the translation with the DEM shaded relief image. His method had practical appeal, but the correction of the rotation angle and scaling were not considered. In this paper, we describe the method to optimize not only the translation but also the rotation angle and scaling using the Fourier-Mellin transform and the Fourier phase-only-correlation (POC) technique. When applied to system-corrected Landsat TM images, the result shows that the parameters obtained by the new method were more accurate than either the original or the re vised parameters contributed by JAXA.