Variational approach for rigid co-registration of optical/SAR satellite images in agricultural areas

Abstract

In this paper the problem of Synthetic Aperture Radar (SAR) and optical satellite images co-registration is considered. Because of the distinct natures of SAR and optical images, there exist huge radiometric and geometric differences between such images. As a result, the traditional registration approaches are no longer applicable in this case and it makes the registration process challenging. Mostly motivated by the crop field monitoring problem, we propose a new variational approach to the co-registration of SAR and optical images. The core idea of our approach is to involve into consideration a constrained optimization problem on the set of affine transformations for which the cost functional is the Lp-cross-correlation between sustainable parts of two fattened skeletons for the selectively smoothed SAR image and the luma component of an optical image, respectively.We discuss the consistency of the proposed statement of this problem, propose the scheme for its regularization, derive the corresponding optimality system, and describe in detail the algorithm for the practical implementation of co-registration procedure. To evaluate the performance of the proposed approach, we illustrate its crucial steps with the help of several numerical experiments and real satellite images.