Efficient algorithm for calculating backscattering from two-dimensional rough sea surface under low grazing angle

An efficient numerical approach is presented for calculating backscattering from rough sea surfaces under low grazing incidence in this paper. The sea surfaces are modeled as random surfaces by using the impedance boundary condition. Different from the conventional integral equation, the self-dual integral equation is used to incorporate the random IBC surfaces. In order to deal with the large simulation domain brought by the low grazing angle, the parallel multilevel fast multipole algorithm (MLFMA) is employed to speed up the simulation. Numerical results of low grazing angle backscattering from 2D rough sea surface are presented to illustrate the accuracy and efficiency of the algorithm. The analyzation of the feature of the scattering from the sea is also provided.