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We demonstrate cantilever-enhanced photoacoustic spectroscopy in the mid-infrared using a supercontinuum source. The approach is broadband, compact, and allows for higher photoacoustic signal intensity and enhanced signal-to-noise ratio as…

Instrumentation and Detectors · Physics 2018-11-14 Tommi Mikkonen , Caroline Amiot , Antti Aalto , Kim Patokoski , Goëry Genty , Juha Toivonen

The Very Large Array (VLA) has been used in C-configuration to map an area \~0.3 square degrees at 1.4 GHz with 5sigma sensitivities of 0.305, 0.325, 0.380 and 0.450 mJy/beam over four equal subareas. Radio properties are presented for 62…

Time-harmonic far-field source array imaging in a two-dimensional waveguide is analyzed. A low-frequency situation is considered in which the diameter of the waveguide is slightly larger than the wavelength, so that the waveguide supports a…

Analysis of PDEs · Mathematics 2020-12-02 Josselin Garnier

In order to determine the relationship between the faint X-ray and faint radio source populations, and hence to help understand the X-ray and radio emission mechanisms in those faint source populations, we have made a deep 1.4GHz Very Large…

Astrophysics · Physics 2009-11-10 N. Seymour , I. M. McHardy , K. F. Gunn

Reconstructing the unknown spectrum of a given X-ray source is a common problem in a wide range of X-ray imaging tasks. For high-energy sources, transmission measurements are mostly used to recover the X-ray spectrum, as a solution to an…

Applied Physics · Physics 2023-07-13 Arthur Walker , Alexandre Friou , Kevin Ginsburger

The coherent image distortions induced by weak gravitational lensing can be used to measure the power spectrum of density inhomogeneities in the universe. We present our on-going effort to detect this effect with the FIRST radio survey,…

Magnetic resonance imaging (MRI) is a potent diagnostic tool, but suffers from long examination times. To accelerate the process, modern MRI machines typically utilize multiple coils that acquire sub-sampled data in parallel. Data-driven…

Image and Video Processing · Electrical Eng. & Systems 2023-10-24 Moritz Erlacher , Martin Zach

In the last 5-10 years, wide-field imaging capabilities and effective mosaicing algorithms have made possible a variety of ambitious interferometric surveys of the Galaxy, resulting in images of unprecedented sensitivity and resolution.…

Astrophysics · Physics 2007-05-23 Bryan Gaensler

Vision Transformers are used via a customized TransUNet architecture, which is a hybrid model combining Transformers into a U-Net backbone, to achieve precise, automated, and fast segmentation of radio astronomy data affected by calibration…

Instrumentation and Methods for Astrophysics · Physics 2025-08-14 Nicoletta Sanvitale , Claudio Gheller , Franco Vazza , Annalisa Bonafede , Virginia Cuciti , Emanuele De Rubeis , Federica Govoni , Matteo Murgia , Valentina Vacca

Optical weak lensing surveys have become a powerful tool for precision cosmology, but remain subject to systematic effects that can severely bias cosmological parameter estimates if not carefully removed. We discuss the possibility of…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-22 Philip Bull , Ian Harrison , Eric Huff

This paper presents a new method for the reconstruction of weak lensing mass maps. It uses the multiscale entropy concept, which is based on wavelets, and the False Discovery Rate which allows us to derive robust detection levels in wavelet…

Astrophysics · Physics 2009-11-10 Jean-Luc Starck , Sandrine Pires , Alexandre Refregier

We study the faint radio population using wide-field very long baseline interferometry (VLBI) observations of 2865 known radio sources in the Cosmic Evolution Survey (COSMOS) field. The main objective of the project was to determine where…

We present the first sub-mJy ($\approx0.7$ mJy beam$^{-1}$) survey to be completed below 100 MHz, which is over an order of magnitude deeper than previously achieved for widefield imaging of any field at these low frequencies. The high…

We consider sensor array imaging for simultaneous noise blended sources. We study a migration imaging functional and we analyze its sensitivity to singular perturbations of the speed of propagation of the medium. We consider two kinds of…

Analysis of PDEs · Mathematics 2012-10-09 Ennio Fedrizzi

An experimental investigation of sub-wavelength imaging by a wire medium slab is performed. A complex-shaped near field source is used in order to test imaging performance of the device. It is demonstrated that the ultimate bandwidth of…

Materials Science · Physics 2015-06-25 Pavel A. Belov , Yan Zhao , Sunil Sudhakaran , Akram Alomainy , Yang Hao

The broad-bandwidth capabilities of next generation telescopes such as the JVLA mean that the spectrum of any given source varies significantly within the bandwidth of any given observation. Detailed spectral analysis taking this variation…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-18 Jeremy Harwood , Martin Hardcastle , Judith Croston , Joanna Goodger

Standard rheometers assess mechanical properties of viscoelastic samples up to 100~Hz, which often hinders the assessment of the local-scale dynamics. We demonstrate that high-frequency analysis can be achieved by inducing broadband…

We propose an illumination strategy for interferometric imaging that allows for robust depth recovery from intensity-only measurements. For an array with colocated sources and receivers, we show that all the possible interferometric data…

Optimization and Control · Mathematics 2016-11-30 Miguel Moscoso , Alexei Novikov , George Papanicolaou , Chrysoula Tsogka

A new model-based image adjustment for the enhancement of multi-resolution image fusion or pansharpening is proposed. Such image adjustment is needed for most pansharpening methods using panchromatic band and/or intensity image (calculated…

Image and Video Processing · Electrical Eng. & Systems 2021-03-05 Gintautas Palubinskas

Interferometry is a powerful technique for making sensitive, high-fidelity images of the sky, but is limited in its ability to measure extended or diffuse emission. Better images of extended astronomical objects can be obtained by…

Instrumentation and Methods for Astrophysics · Physics 2020-06-12 Brian S. Mason