Using DGPS trajectory to evaluate an ortho-rectification method designed for flash radar images

The airborne flash SAR is a versatile device to produce high resolution radar images. In order to produce ortho-images, the distortions due to the complex real trajectory, system errors, and terrain elevation must be rectified. We have conceived (and previously presented) a rectification method specific to the flash radar. To estimate the quality of the rectification and the limit of our method (and of the geometric model) we have used a very accurate trajectory (DGPS) to produce undistorted images. The comparison of these images with the ones obtained by our method shows that our method works well and that the main limit to the rectification is the accuracy of the cartographic data used