Physical optics inverse diffraction

A general method for solving the inverse diffraction problem is presented. It is based on an identity of Bojarski which states thatγ(x)andΓ(p)are a Fourier transform pair. Hereγ(x)is the characteristic function of the target (γ=1inside the target,γ = 0outside),p = (2ω/c)J, the frequency,Jis a unit vector specifying the aspect, andΓ(P)can be obtained by measurement of the backscattered electromagnetic far field at frequencyω = (c/2)|P|and aspectJ=|p|⁻¹p. If data is obtained in any subsetDofpspace, the method yields partial or complete information about the target geometry. It is used to rederive earlier results very simply and to obtain a significant new solution, in which the target geometry is completely determined using frequencies only in a practical frequency band and aspects in a narrow cone.