Results 31 to 40 of about 66,156 (175)
Toward an Estimation of the Optical Feedback Factor C on the Fly for Displacement Sensing
Sensors, 2021 In this paper, a method based on the inherent event-based sampling capability of laser optical feedback interferometry (OFI) is proposed to assess the optical feedback factor C when the laser operates in the moderate and strong feedback regimes.
Olivier D. Bernal +3 more
doaj +1 more source
Singularities in Speckled Speckle: Statistics [PDF]
, 2008 Random optical fields with two widely different correlation lengths generate far field speckle spots that are themselves highly speckled. We call such patterns speckled speckle, and study their critical points (singularities and stationary points) using analytical theory and computer simulations.
arxiv +1 more source
Singularities in Speckled Speckle [PDF]
, 2007 Speckle patterns produced by random optical fields with two (or more) widely different correlation lengths exhibit speckle spots that are themselves highly speckled. Using computer simulations and analytic theory we present results for the point singularities of speckled speckle fields: optical vortices in scalar (one polarization component) fields; C ...
arxiv +1 more source
A Practical Solution for SAR Despeckling With Adversarial Learning Generated Speckled-to-Speckled Images [PDF]
IEEE Geoscience and Remote Sensing Letters,(2020)1-5, 2019 In this letter, we aim to address a synthetic aperture radar (SAR) despeckling problem with the necessity of neither clean (speckle-free) SAR images nor independent speckled image pairs from the same scene, and a practical solution for SAR despeckling (PSD) is proposed.
arxiv +1 more source
Photonics, 2023 Vortex beams carry orbital angular momentum (OAM), and their inherent infinite dimensional eigenstates can enhance the ability for optical communication and information processing in the classical and quantum fields.
Yanzhu Zhang +4 more
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Speckle Temporal Stability in eXtreme Adaptive Optics Coronagraphic Images [PDF]
, 2012 The major noise source limiting high-contrast imaging is due to the presence of quasi-static speckles. Speckle noise originates from wavefront errors caused by various independent sources, and it evolves on different timescales pending to their nature.
arxiv +1 more source
Despeckling of Ultrasound Images Using Block Matching and SVD in Sparse Representation
Sensors, 2022 This work proposes a novel scheme for speckle suppression on medical images acquired by ultrasound sensors. The proposed method is based on the block matching procedure by using mutual information as a similarity measure in grouping patches in a ...
Rogelio Reyes-Reyes +5 more
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Polarimetric SAR Speckle Reduction by Hybrid Iterative Filtering
IEEE Access, 2020 Speckle filtering in synthetic aperture radar polarimetry (PolSAR) is essential for the extraction of significant information. In this study, the authors introduced a hybrid iterative filtering scheme.
Mohamed Yahia +4 more
doaj +1 more source
Speckle noise reduction techniques for high-dynamic range imaging [PDF]
ComptesRendusPhysique8:349-354,2007, 2007 High-dynamic range imaging from space in the visible, aiming in particular at the detection of terrestrial exoplanets, necessitates not only the use of a coronagraph, but also of adaptive optics to correct optical defects in real time. Indeed, these defects scatter light and give birth to speckles in the image plane.
arxiv +1 more source
Bilateral Distance Based Filtering for Polarimetric SAR Data
Remote Sensing, 2013 This paper introduces a non-linear Polarimetric SAR data filtering approach able to preserve the edges and small details of the data. It is based on exploiting the data locality in both, the spatial and the polarimetric domains, in order to avoid mixing ...
Alberto Alonso-González +3 more
doaj +1 more source