A multiblock generalized forward-backward method

In a previous work, the generalized forward-backward (GFB) method has been proposed to obtain the scattering from targets on rough ocean-like surfaces. In this paper a generalization of the GFB method is presented which allows larger targets and multiple targets to be handled efficiently. The solution is based on a multiblock resolution of each target which is divided into a set of small subregions (blocks). The solution is obtained via a standard method of moments matrix factorization for the small blocks, combined with a conventional forward-backward iterative procedure to account both for the interactions between blocks and for the regions without obstacles. A relaxation parameter is also introduced to improve convergence. The proposed method provides a general formulation completely independent of the number, the size and the position of the obstacles over the sea surface and allows a significant reduction in the computational and storage costs.