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We derive an analytic expression for the instrument profile of a slit spectrograph, also known as the line spread function. While this problem is not new, our treatment relies on the operatorial approach to the description of diffractive…

Optics · Physics 2015-06-22 R. Casini , A. G. de Wijn

This article extends the concept of compressed sensing to signals that are not sparse in an orthonormal basis but rather in a redundant dictionary. It is shown that a matrix, which is a composition of a random matrix of certain type and a…

Probability · Mathematics 2010-11-10 Holger Rauhut , Karin Schnass , Pierre Vandergheynst

Sampling theory has benefited from a surge of research in recent years, due in part to the intense research in wavelet theory and the connections made between the two fields. In this survey we present several extensions of the Shannon…

Information Theory · Computer Science 2008-12-17 Y. C. Eldar , T. Michaeli

Rotation measure synthesis allows the estimation of Faraday dispersion via a Fourier transform and is the primary tool to probe cosmic magnetic fields. We show this can be considered mathematically equivalent to the one dimensional…

Instrumentation and Methods for Astrophysics · Physics 2020-05-13 Luke Pratley , Melanie Johnston-Hollitt

The sampling of graph signals has recently drawn much attention due to the wide applications of graph signal processing. While a lot of efficient methods and interesting results have been reported to the sampling of band-limited or smooth…

Signal Processing · Electrical Eng. & Systems 2025-01-01 Yingcheng Lai , Li Chai , Jinming Xu

We propose a method for tailoring the frequency spectrum of bright squeezed vacuum by generating it in a nonlinear interferometer, consisting of two down-converting nonlinear crystals separated by a dispersive medium. Due to a faster…

Quantum Physics · Physics 2016-01-20 T. Sh. Iskhakov , S. Lemieux , A. Perez , R. W. Boyd , G. Leuchs , M. Chekhova

Wavelets have been used extensively for several years now in astronomy for many purposes, ranging from data filtering and deconvolution, to star and galaxy detection or cosmic ray removal. More recent sparse representations such ridgelets…

Instrumentation and Methods for Astrophysics · Physics 2009-03-20 Jean-Luc Starck , Jerome Bobin

In a previous paper we described a method of estimating the single-measurement bias to be expected in astrometric observations of targets in crowded fields with the future Space Interferometry Mission (SIM). That study was based on a…

Astrophysics · Physics 2009-11-13 R. Sridharan , Ronald J. Allen

Low-frequency radio observatories are reaching unprecedented levels of sensitivity in an effort to detect the 21 cm signal from the Cosmic Dawn. High precision is needed because the expected signal is overwhelmed by foreground…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Adam E. Lanman , Steven G. Murray , Daniel C. Jacobs

Radio interferometry has always faced the problem of incomplete sampling of the Fourier plane. A possible remedy can be found in the promising new theory of compressed sensing (CS), which allows for the accurate recovery of sparse signals…

Instrumentation and Methods for Astrophysics · Physics 2015-12-22 Clara Fannjiang

Given fruitful works in the image monitoring, there is a lack of data-driven tools guiding the practitioners to select proper monitoring procedures. The potential model mismatch caused by the arbitrary selection could deviate the empirical…

Methodology · Statistics 2023-10-03 Tingnan Gong

We describe a proof-of-principal experiment demonstrating the use of spread spectrum technology at the single photon level. We show how single photons with a prescribed temporal shape, in the presence of interfering noise, may be hidden and…

Atomic Physics · Physics 2015-05-18 Chinmay Belthangady , Chih-Sung Chuu , Ite A. Yu , G. Y. Yin , J. M. Kahn , S. E. Harris

This chapter focuses on active sensing using sparse arrays. In active sensing applications, such as radar, sonar, wireless communications, and medical ultrasound, a collection of sensors probes the environment by emitting self-generated…

Signal Processing · Electrical Eng. & Systems 2026-01-22 Robin Rajamäki , Visa Koivunen

Presented is a novel way to combine snapshot compressive imaging and lateral shearing interferometry in order to capture the spatio-spectral phase of an ultrashort laser pulse in a single shot. A deep unrolling algorithm is utilised for the…

We discuss a novel sparsity prior for compressive imaging in the context of the theory of compressed sensing with coherent redundant dictionaries, based on the observation that natural images exhibit strong average sparsity over multiple…

Information Theory · Computer Science 2013-05-03 Rafael E. Carrillo , Jason D. McEwen , Dimitri Van De Ville , Jean-Philippe Thiran , Yves Wiaux

Accurate estimates of Instrument Spectral Response Functions (ISRFs) are crucial in order to have a good characterization of high resolution spectrometers. Spectrometers are composed of different optical elements that can induce errors in…

Numerical Analysis · Mathematics 2024-04-09 Jihanne El Haouari , Jean-Michel Gaucel , Christelle Pittet , Jean-Yves Tourneret , Herwig Wendt

Recently, there has been a significant interest in developing cooperative sensing systems for certain types of wireless applications. In such systems, a group of sensing nodes periodically collect measurements about the signals being…

Information Theory · Computer Science 2015-06-11 Harish Ganapathy , Constantine Caramanis , Lei Ying

Natural signals and images are well-known to be approximately sparse in transform domains such as Wavelets and DCT. This property has been heavily exploited in various applications in image processing and medical imaging. Compressed sensing…

Machine Learning · Computer Science 2015-10-26 Saiprasad Ravishankar , Yoram Bresler

Modern radio telescopes, such as the Square Kilometre Array (SKA), will probe the radio sky over large fields-of-view, which results in large w-modulations of the sky image. This effect complicates the relationship between the measured…

Instrumentation and Methods for Astrophysics · Physics 2017-07-14 Arwa Dabbech , Laura Wolz , Luke Pratley , Jason D. McEwen , Yves Wiaux

The central idea of compressed sensing is to exploit the fact that most signals of interest are sparse in some domain and use this to reduce the number of measurements to encode. However, if the sparsity of the input signal is not precisely…

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