Analysis of the phase unwrapping algorithm

Several workers have recently proposed digital techniques for high-resolution imaging through the turbulent atmosphere. The basic concept of these algorithms is to calculate and average phase angles of a series of image Fourier transforms to suppress the unwanted atmospheric effects on image resolution. Since computed phase angles contain the ambiguities of integral multiples of 2 pirad, it is necessary to obtain continuous phase curves without the ambiguities before averaging. This process of eliminating the ambiguities is called phase tracking or unwrapping. A similar problem has been discussed by Oppenheim and Schafer and Tribolet in the context of realization of a certain homomorphic signal processing system.