At last, EM scattering from three-dimensional object is studied particularly, and the pairs of current elements which are perpendicular to each other and tangential to the auxiliary surface are introduced to calculate scattering field from two-dimensional Gaussian rough surface. 最后,详细研究了三维导体目标的无网格法,并引入了与辅助表面相切且相互正交的辅助电流源,进而应用到计算二维高斯导体粗糙面的散射场。