Publications associées à Intrinsic advantages of the w component and spherical imaging for wide-field radio interferometry

Learning Linearized Degradation of Health Indicators using Deep Koopman Operator Approach

With the current trend of increasing complexity of industrial systems, the construction and monitoring of health indicators becomes even more challenging. Given that health indicators are commonly employed to predict the end of life, a crucial criterion fo ...

Research Publishing2023

A geometric optimal control approach for imitation and generalization of manipulation skills

Sylvain Calinon, Amirreza Razmjoo Fard, Jie Zhao

Daily manipulation tasks are characterized by regular features associated with the task structure, which can be described by multiple geometric primitives related to actions and object shapes. Only using Cartesian coordinate systems cannot fully represent ...

Elsevier2023

Method and system for generating a three-dimensional model based on spherical photogrammetry

Pierre-André Mudry, Frédéric Kaplan, Nils Hamel, Albane Bénédicte Descombes

A computer-implemented method is proposed for creating a three-dimensional model of the environment. The method comprises the steps of planning (105) a trajectory for a moving system carrying an omnidirectional camera comprising a first image sensor facing ...

2021

UCLID-Net: Single View Reconstruction in Object Space

Pascal Fua, Edoardo Remelli, Benoît Alain René Guillard

Most state-of-the-art deep geometric learning single-view reconstruction approaches rely on encoder-decoder architectures that output either shape parametrizations or implicit representations. However, these representations rarely preserve the Euclidean st ...

2020

Structural and functional brain imaging using extended-focus optical coherence tomography and microscopy

Paul James Marchand

Neuroimaging techniques aim at revealing the anatomy and functional organisation of cerebral structures. Over the past decades, functional magnetic resonance imaging (fMRI) has revolutionized our understanding of human cerebral physiology through its abili ...

EPFL2018

Low-dimensional data embedding for scalable astronomical imaging in the SKA telescope era

Vijay Kartik

Astronomy is one of the oldest sciences known to humanity. We have been studying celestial objects for millennia, and continue to peer deeper into space in our thirst for knowledge about our origins and the universe that surrounds us. Radio astronomy -- ob ...

EPFL2018

Improved calibration of vertical scanning optical profilometers for spherical profiles measurements

Wilfried Noell, Toralf Scharf, Jeremy Béguelin

A new method for calibrating optical scanning profilometers is presented. Especially adapted to spherical and aspherical profile measurements, it shows an increase of accuracy bigger than one order of magnitude for radius of curvature measurements. Calibra ...

2018

Sampling and Exact Reconstruction of Pulses with Variable Width

Martin Vetterli, Loïc Arnaud Baboulaz, Gilles Baechler, Adam James Scholefield

Recent sampling results enable the reconstruction of signals composed of streams of fixed-shaped pulses. These results have found applications in topics as varied as channel estimation, biomedical imaging and radio astronomy. However, in many real signals, ...

Institute of Electrical and Electronics Engineers2017

Superresolved synthetic aperture microscope

Theo Lasser, Adrien Charles-François Raymond Descloux, Daniel Pawel Szlag, Tomas Lukes

Optical system comprising a synthetic aperture generating unit; said synthetic aperture generating unit being adapted for generating several apertures, which are correlated by interference for improving contrast and/or resolution based on the interference ...

2017

Label-free three-dimensional imaging of Caenorhabditis elegans with visible optical coherence microscopy

Theo Lasser, Paul James Marchand, Séverine Coquoz, Johan Auwerx, Arno Pino Bouwens, Laurent Mouchiroud, Daniel Pawel Szlag, Vincenzo Sorrentino

Fast, label-free, high-resolution, three-dimensional imaging platforms are crucial for high-throughput in vivo time-lapse studies of the anatomy of Caenorhabditis elegans, one of the most commonly used model organisms in biomedical research. Despite the ne ...

Public Library of Science2017

Highly-sensitive distributed birefringence measurements based on a two-pulse interrogation of a dynamic Brillouin grating

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Andrey Denisov

A method for distributed birefringence measurements is proposed based on the interference pattern generated by the interrogation of a dynamic Brillouin grating (DBG) using two short consecutive optical pulses. Compared to existing DBG interrogation techniq ...

Ieee2017

Direct unwrapped phase estimation in phase shifting interferometry using Levenberg-Marquardt algorithm

Pramod Rastogi, Rishikesh Dilip Kulkarni

An algorithm for the direct unwrapped phase estimation from the linearly phase shifted interferograms is presented. The temporal fringe intensity along each pixel is represented as a function of fringe amplitude, phase step and the searched phase. These pa ...

Iop Publishing Ltd2017

Interferometric synthetic aperture microscopy for extended focus optical coherence microscopy

Theo Lasser, Paul James Marchand, Séverine Coquoz, Arno Pino Bouwens, Jérôme Extermann

Optical coherence microscopy (OCM) is an interferometric technique providing 3D images of biological samples with micrometric resolution and penetration depth of several hundreds of micrometers. OCM differs from optical coherence tomography (OCT) in that i ...

2017

Effective a posteriori Co-Phasing of Interferometric Fringe Data

Ferréol Arnaud Marie Soulez

We have recently shown that a posteriori co-phasing of multi-spectral interferograms was possible.(1) In this contribution, we extend our approach so that it can be applied to actual data as provided by AMBER(2) or MATISSE instruments. The main advantage o ...

SPIE2016

Robust sparse image reconstruction of radio interferometric observations with PURIFY

Yves Wiaux, Jason Douglas McEwen, Rafael Eduardo Carrillo Rangel

Next-generation radio interferometers, such as the Square Kilometre Array (SKA), will revolutionise our understanding of the universe through their unprecedented sensitivity and resolution. However, to realise these goals significant challenges in image an ...

OUP2016

Towards an incoherent off-axis digital holographic microscope

Frédéric Montfort, Christian Depeursinge

We propose and experimentally demonstrate a system in which off-axis digital holographic microscopy is realized using a broadband illumination source. Single-shot holographic measurements are enabled, while the coherence noise is removed thanks to the broa ...

Spie-Int Soc Optical Engineering2015

Off-axis digital holographic camera for quantitative phase microscopy

Frédéric Montfort, Christian Depeursinge, Christophe Moser, Zahra Monemhaghdoust

We propose and experimentally demonstrate a digital holographic camera which can be attached to the camera port of a conventional microscope for obtaining digital holograms in a self-reference configuration, under short coherence illumination and in a sing ...

Optical Soc Amer2014

Light confinement effect of non-spherical nanoscale solid immersion lenses

Hans Peter Herzig, Gaël David Osowiecki, David Nguyen, Myun Sik Kim, Toralf Scharf

We report on the light confinement effect observed in non-ideally shaped (i.e., non-spherical) nanoscale solid immersion lenses (SILs). To investigate this effect, nanostructures of various shapes are fabricated by electron-beam lithography. When completel ...

Spie-Int Soc Optical Engineering2013

Further study on iterative control loop for aberration correction in imaging systems with single mode fibre aperture

An iterative control system was designed for compensation of wavefront aberration utilizing a micromachined deformable mirror through simulated annealing algorithm. 37 elements within a deformable mirror are controlled individually in a closed-loop to maxi ...

Natl Inst Optoelectronics2013

Tokamak coordinate conventions: COCOS

Olivier Sauter

Dealing with electromagnetic fields, in particular current and related magnetic fields, yields "natural" physical vector relations in 3-D. However, when it comes to choosing local coordinate systems, the "usual" right-handed systems are not necessarily the ...

Elsevier Science Bv2013