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Related papers: Fourier Plane Image Combination by Feathering

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In ghost imaging schemes information about an object is extracted by measuring the correlation between a beam that passed the object and a reference beam. We present a spatial averaging technique that substantially improves the imaging…

Quantum Physics · Physics 2009-11-10 M. Bache , E. Brambilla , A. Gatti , L. A. Lugiato

Extracting as much information as possible about an object when probing with a limited number of photons is an important goal with applications from biology and security to metrology. Imaging with a few photons is a challenging task as the…

We present a graphical interface designed to demonstrate the techniques of radio interferometry used by telescopes like ALMA, e-Merlin, the JVLA and SKA, in a manner accessible to the general public. Interferometry is an observational tech-…

Instrumentation and Methods for Astrophysics · Physics 2012-11-02 Adam Avison , Samuel J George

We introduce and experimentally implement Fourier-plane phase synchronization for optical microscopy, and demonstrate its performance with interferometric scattering microscopy. By combining a photothermal phase plate and laser beam…

Quantum entanglement-based imaging promises significantly increased resolution by extending the spatial separation of optical collection apertures used in very-long-baseline interferometry for astronomy and geodesy. We report a table-top…

We present an approach for improving spatial frequency sampling in active incoherent millimeter-wave (AIM) imaging systems using frequency diversity. AIM imaging relies on active transmission of spatio-temporally incoherent signals to…

Signal Processing · Electrical Eng. & Systems 2025-03-12 Jorge R. Colon-Berrios , Jeffrey A. Nanzer

Astronomical optical interferometers sample the Fourier transform of the intensity distribution of a source at the observation wavelength. Because of rapid perturbations caused by atmospheric turbulence, the phases of the complex Fourier…

Instrumentation and Methods for Astrophysics · Physics 2014-10-07 Antony Schutz , André Ferrari , David Mary , Férréol Soulez , Éric Thiébaut , Martin Vannier

In radio astronomy, holography is a commonly used technique to create an image of the electric field distribution in the aperture of a dish antenna. The image is used to detect imperfections in the reflector surface. Similarly, holography…

Instrumentation and Methods for Astrophysics · Physics 2021-06-09 U. Kiefner , R. B. Wayth , D. B. Davidson , M. Sokolowski

This paper investigates the possibility of improving radio interferometric images using an algorithm inspired by an optical method known as "lucky imaging", which would give more weight to the best-calibrated visibilities used to make a…

Instrumentation and Methods for Astrophysics · Physics 2018-07-18 Etienne Bonnassieux , Cyril Tasse , Oleg Smirnov , Philippe Zarka

Radio interferometers observe the Fourier space of the sky, at locations determined by the array geometry. Before a real space image is constructed by a Fourier transform, the data is weighted to improve the quality of reconstruction. Two…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Sarod Yatawatta

While, in general, interferometers provide high spatial resolution for imaging small-scale structure (corresponding to high spatial frequencies in the Fourier plane), single-dishes can be used to image the largest spatial scales…

Astrophysics · Physics 2007-05-23 S. Stanimirovic

Diffraction tomography aims to recover an object's scattering potential from measured wave fields. In the classical setting, the object is illuminated by plane waves from many directions, and the Fourier diffraction theorem provides a…

Numerical Analysis · Mathematics 2026-03-11 Peter Elbau , Noemi Naujoks

Several Scientific and engineering applications require merging of sampled images for complex perception development. In most cases, for such requirements, images are merged at intensity level. Even though it gives fairly good perception of…

Computer Vision and Pattern Recognition · Computer Science 2014-08-01 T. R. Gopalakrishnan Nair , Richa Sharma

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

Speckle Imaging based on triple correlation is a very efficient image reconstruction technique which is used to retrieve Fourier phase information of the object in presence of atmospheric turbulence. We have developed both Direct Bispectrum…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha

A new generation of interferometric instruments is emerging which aim to use intensity mapping of redshifted $21\,$cm radiation to measure the large-scale structure of the Universe at $z\simeq 1-2$ over wide areas of sky. While these…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Martin White , Nikhil Padmanabhan

The spatial-frequency coverage of a radio interferometer is increased by combining samples acquired at different times and observing frequencies. However, astrophysical sources often contain complicated spatial structure that varies within…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 U. Rau

Optical interferometers may not require a phase-stable optical link between the stations if instead sources of quantum-mechanically entangled pairs could be provided to them, enabling long baselines. We developed a new variation of this…

Instrumentation and Methods for Astrophysics · Physics 2023-02-01 Zhi Chen , Andrei Nomerotski , Anže Slosar , Paul Stankus , Stephen Vintskevich

Radio interferometers consisting of identical antennas arranged on a regular lattice permit fast Fourier transform beamforming, which reduces the correlation cost from $\mathcal{O}(n^2)$ in the number of antennas to $\mathcal{O}(n\log n)$.…

Instrumentation and Methods for Astrophysics · Physics 2019-05-20 Kiyoshi W. Masui , J. Richard Shaw , Cherry Ng , Kendrick M. Smith , Keith Vanderlinde , Adiv Paradise

Astronomical optical interferometers (OI) sample the Fourier transform of the intensity distribution of a source at the observation wavelength. Because of rapid atmospheric perturbations, the phases of the complex Fourier samples…

Instrumentation and Methods for Astrophysics · Physics 2015-03-06 Antony Schutz , André Ferrari , David Mary , Eric Thiébaut , Ferréol Soulez