Robust phase-unwrapping techniques: a comparison

In this paper we demonstrate the theoretical equivalence of two robust techniques for two-dimensional phase unwrapping. The first is based on the least-squares (LS) approach, and the second is based on Green’s formulation. To be theoretically comparable with Green’s method, the LS phase unwrapping is formulated in the continuous domain, leading to the minimization of a specific functional. Subsequently, we investigate the computational requirements of the procedures implementing the two methods. To do this, we have modified the first Green’s identity-based algorithm to account for periodic phase patterns. This reformulation allows us to compare the existing efficient LS procedures and leads to a procedure whose memory and computational requirements are less stringent than those presented in Fornaro et al. [ IEEE Trans. Geosci. Remote Sens.34, 720 ( 1996)].