Results 191 to 200 of about 22,111 (245)

Exploiting Sparsity for Phase Unwrapping

IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium, 2019
We consider the problem of unwrapping the phase of two-dimensional interferograms, and adopt a known formulation as a sparse optimization problem. Many algorithms have been developed for solving sparse optimization problems that occur in the field of compressive sensing; in this work, we adapt one such algorithm for use in the unwrapping problem.
Rick Chartrand, Matthew T. Calef, Michael S. Warren   +2 more
openaire   +1 more source

Fast and accurate phase unwrapping

Interspeech 2015, 2015
More and more speech technology and signal processing applications make use of the phase information. A proper estimation and representation of the phase goes inextricably along with a correct phase unwrapping, which refers to the problem of finding the instance of the phase function chosen to ensure continuity.
Thomas Drugman, Yannis Stylianou
openaire   +1 more source

Singularity-Spreading Phase Unwrapping

IEEE Transactions on Geoscience and Remote Sensing, 2007
How to process phase singular points (SPs), or residues, is a difficult problem in a 2-D phase-unwrapping process to generate digital elevation maps (DEMs). Although the minimum-cost network-flow method is an effective and widely used technique, some problems still remain.
Ryo Yamaki, Akira Hirose 0001
openaire   +1 more source

Frequency Estimation by Phase Unwrapping

IEEE Transactions on Signal Processing, 2010
Single frequency estimation is a long-studied problem with application domains including radar, sonar, telecommunications, astronomy and medicine. One method of estimation, called phase unwrapping, attempts to estimate the frequency by performing linear regression on the phase of the received signal.
Robby G. McKilliam, Barry G. Quinn, I. Vaughan L. Clarkson, William Moran 0001   +3 more
openaire   +4 more sources

Phase unwrapping of digital signals

IEEE Transactions on Acoustics, Speech, and Signal Processing, 1989
In order to unwrap the phase of a digital signal, the signal's z-plane zeros, which lie close to the unit circle, are located by repeatedly expanding the z-plane in small steps and detecting a zero's crossing of the unit circle. This detection is accomplished by determining the step which gives rise to a maximum change in the phase at any frequency ...
openaire   +1 more source

Phase unwrapping by region growing

Applied Optics, 2003
The phase unwrapping problem consists in mingling out an integer field whose values make the original wrapped phase field continuous. Even if in principle the problem is very simple--a direct integration of the wrapped phase field suffices--in the presence of noise and/or undersampling, the solution is no longer unique and the direct integration ...
openaire   +3 more sources

Multiresolution phase unwrapping for SAR interferometry

IEEE Transactions on Geoscience and Remote Sensing, 1999
An approach to two-dimensional (2D) phase unwrapping for synthetic aperture radar (SAR) interferometry is presented, based on separate steps of coarse phase and fine phase estimation. A technique called adaptive multiresolution is introduced for local fringe frequency estimation, in which difference frequencies between resolution levels are estimated ...
Davidson, Gordon, Bamler, Richard
openaire   +2 more sources

Unwrapping highly wrapped phase using Nonlinear Multi Echo phase unwrapping

2015
The unwrapping problem has been a major topic of research for over a decade. A variety of algorithms were suggested, but a correct solution is by no means guaranteed. In addition, many of these techniques are timeconsuming issues. In this work, we propose a simple and fast method, which combines conventional temporal unwrapping with a nonlinear phase ...
Fatnassi C., Fatnassi C., Boucenna R., Zaidi H.   +3 more
openaire   +1 more source

New regularization scheme for phase unwrapping

Applied Optics, 1998
A new, to our knowledge, algorithm for the phase unwrapping (PU) problem that is based on stochastic relaxation is proposed and analyzed. Unlike regularization schemes previously proposed to handle this problem, our approach dispells the following two assumptions about the solution: a Gaussian model for noise and the magnitude of the true phase-field ...
GUERRIERO L, NICO G, PASQUARIELLO G, STRAMAGLIA, Sebastiano   +3 more
openaire   +3 more sources

Phase Unwrapping Algorithms: A Comparison

2000
Over the last few years a great deal of work has been done to improve the reliability of phase unwrapping algorithms. Many articles are to be found in the technical literature claiming the robustness and noise immunity of the proposed algorithm.
BALDI, ANTONIO, BERTOLINO, FILIPPO, GINESU, FRANCESCO   +2 more
openaire   +2 more sources