Some new considerations are also added. ICTP Preprint No. We show a method for comparing and reconstructing two similar amplitude-only structures, which are composed by the same number of identical apertures. The structures are two-dimensional and differ only in the location of one of the apertures. The method is based on a subtraction algorithm, which involves the autocorrelations and cross-correlation functions of the compared structures.
Experimental results illustrate the feasibility of the method.