Thibaut Vidal, Pontifical Catholic University of Rio de Janeiro

Abstract

Phase unwrapping is the process of recovering a continuous phase signal from an original signal wrapped in the [-π, π] interval. It is a critical step of coherent signal processing, with applications such as synthetic aperture radar, acoustic imaging, magnetic resonance, X-ray crystallography, and seismic processing, and thus the subject of extensive research. We reformulate the phase unwrapping problem under L0-norm as the search for a minimum-cost balanced spanning forest in a graph where the vertices represent the residues of the wrapped phase, and introduce branch-and-cut, column generation and metaheuristic approaches. These approaches lead us one step closer towards good solutions for this problem, which were previously viewed, in the signal processing literature, as highly desirable but nonetheless intractable.

Video