Dear editor,rnAccording to the electromagnetic theory,each scattering center(SC)is equivalent to a mathematical discontinuity in Stratton-Chu integrals[1].From the view of geometri-cal structure,the positions of SCs correspond to the dis-continuities of surface and specular points.Therefore,the signatures of SCs in radar images can represent the actual geometric characteristics.Three-dimension SC model has been successfully applied for the radar target reconstruction and automatic target recognition(ATR)[2].