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This work discusses an extension to conventional low-coherence interferometry by the introduction of dispersion-encoding. The extension facilitates the measurement of surface height profiles with sub-nm resolution. The selection of a…

Optics · Physics 2021-05-24 Christopher Taudt

We study array imaging of a sparse scene of point-like sources or scatterers in a homogeneous medium. For source imaging the sensors in the array are receivers that collect measurements of the wave field. For imaging scatterers the array…

Numerical Analysis · Mathematics 2015-07-03 Liliana Borcea , Ilker Kocyigit

Optical interferometers provide multiple wavelength measurements. In order to fully exploit the spectral and spatial resolution of these instruments, new algorithms for image reconstruction have to be developed. Early attempts to deal with…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Éric Thiébaut , Ferréol Soulez , Loïc Denis

Radio interferometry invariably suffers from an incomplete coverage of the spatial Fourier space, which leads to imaging artifacts. The current state-of-the-art technique is to create an image by Fourier-transforming the incomplete…

Instrumentation and Methods for Astrophysics · Physics 2024-12-19 F. Geyer , K. Schmidt , J. Kummer , M. Brüggen , H. W. Edler , D. Elsässer , F. Griese , A. Poggenpohl , L. Rustige , W. Rhode

This letter proposes a novel distributed compressed estimation scheme for sparse signals and systems based on compressive sensing techniques. The proposed scheme consists of compression and decompression modules inspired by compressive…

Information Theory · Computer Science 2015-02-05 S. Xu , R. C. de Lamare , H. V. Poor

Spectrum sensing is an essential functionality that enables cognitive radios to detect spectral holes and opportunistically use under-utilized frequency bands without causing harmful interference to primary networks. Since individual…

Information Theory · Computer Science 2009-11-13 Zhi Quan , Shuguang Cui , Ali. H. Sayed , H. Vincent Poor

Advances of information-theoretic understanding of sparse sampling of continuous uncoded signals at sampling rates exceeding the Landau rate were reported in recent works. This work examines sparse sampling of coded signals at sub-Landau…

Information Theory · Computer Science 2013-03-04 Michael Peleg , Shlomo Shamai

Detection of a signal under noise is a classical signal processing problem. When monitoring spatial phenomena under a fixed budget, i.e., either physical, economical or computational constraints, the selection of a subset of available…

Signal Processing · Electrical Eng. & Systems 2018-08-01 Mario Coutino , Sundeep Prabhakar Chepuri , Geert Leus

Non-invasive detection of objects embedded inside an optically scattering medium is essential for numerous applications in engineering and sciences. However, in most applications light at visible or near-infrared wavebands is scattered by…

We discuss the far-field spatio-temporal cross-correlations of waves multiple-scattered in a turbid medium in which is embedded a hidden heterogeneous region (inclusion) characterized by a distinct scatterer dynamics (as compared to the…

Soft Condensed Matter · Physics 2007-05-23 S. E. Skipetrov

We study imaging with an array of sensors that probes a medium with single frequency electromagnetic waves and records the scattered electric field. The medium is known and homogenous except for some small and penetrable inclusions. The…

Analysis of PDEs · Mathematics 2016-09-21 Liliana Borcea , Josselin Garnier

Compressed sensing is a relatively new mathematical paradigm that shows a small number of linear measurements are enough to efficiently reconstruct a large dimensional signal under the assumption the signal is sparse. Applications for this…

Numerical Analysis · Mathematics 2018-01-08 Lenny Fukshansky , Deanna Needell , Benny Sudakov

A pulsar's pulse profile gets broadened at low frequencies due to dispersion along the line of sight or due to multi-path propagation. The dynamic nature of the interstellar medium makes both of these effects time-dependent and introduces…

The pulse widths, dispersion measures and dispersion indices of Fast Radio Bursts (FRB) impose coupled constraints that all models must satisfy. We show that if the dispersion measures resulted from propagation through the intergalactic…

High Energy Astrophysical Phenomena · Physics 2015-01-07 J. I. Katz

Microwave, submillimetre-wave, and far-infrared phased arrays are of considerable importance for astronomy. We consider the behaviour imaging phased arrays and interferometric phased arrays from a functional perspective. It is shown that…

Astrophysics · Physics 2009-11-11 Stafford Withington , George Saklatvala , Michael P. Hobson

This letter proposes a sparse diffusion steepest-descent algorithm for one bit compressed sensing in wireless sensor networks. The approach exploits the diffusion strategy from distributed learning in the one bit compressed sensing…

Machine Learning · Statistics 2016-01-05 Hadi Zayyani , Mehdi Korki , Farrokh Marvasti

Polarised radio synchrotron emission from interstellar, intracluster and intergalactic magnetic fields is affected by frequency-dependent Faraday depolarisation. The maximum polarised intensity depends on the physical properties of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Tigran G. Arshakian , Rainer Beck

In many practical settings one can sequentially and adaptively guide the collection of future data, based on information extracted from data collected previously. These sequential data collection procedures are known by different names,…

Statistics Theory · Mathematics 2013-11-28 Ervin Tánczos , Rui M. Castro

Context. Recently our ability to study stars using asteroseismic techniques has increased dramatically, largely through the use of space based photometric observations. Work has also been done using ground based spectroscopic observations…

Solar and Stellar Astrophysics · Physics 2018-10-03 Jesper Schou

We put forward a method that allows the experimental determination of the entire spatial mode spectrum of any arbitrary monochromatic wave field in a plane normal to its propagation direction. For coherent optical fields, our spatial…

Quantum Physics · Physics 2011-02-08 Gabriel F. Calvo , Antonio Picón , Roberta Zambrini
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