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Energy consumption and hardware cost of signal digitization together with the management of the resulting data volume form serious issues for high-rate measurement systems with multiple sensors. Switching to binary sensing front-ends…

Instrumentation and Methods for Astrophysics · Physics 2019-07-16 Manuel S. Stein

The new generation of radio interferometers is characterized by high sensitivity, wide fields of view and large fractional bandwidth. To synthesize the deepest images enabled by the high dynamic range of these instruments requires us to…

Instrumentation and Methods for Astrophysics · Physics 2018-04-25 C. Tasse , B. Hugo , M. Mirmont , O. Smirnov , M. Atemkeng , L. Bester , M. J. Hardcastle , R. Lakhoo , S. Perkins , T. Shimwell

We present a novel deep learning framework that models the scene dependent image processing inside cameras. Often called as the radiometric calibration, the process of recovering RAW images from processed images (JPEG format in the sRGB…

Computer Vision and Pattern Recognition · Computer Science 2017-07-27 Seonghyeon Nam , Seon Joo Kim

In view of contemporary panoramic camera-laser scanner system, the traditional calibration method is not suitable for panoramic cameras whose imaging model is extremely nonlinear. The method based on statistical optimization has the…

Computer Vision and Pattern Recognition · Computer Science 2017-09-14 Mingwei Cao , Ming Yang , Chunxiang Wang , Yeqiang Qian , Bing Wang

Optical aberrations prevent telescopes from reaching their theoretical diffraction limit. Once estimated, these aberrations can be compensated for using deformable mirrors in a closed loop. Focal plane wavefront sensing enables the…

Radar is a critical tool for maintaining knowledge of the many ob-jects in low Earth orbit and thus for maintaining confidence that societies around the world are secure against a variety of space-based threats. It is therefore important to…

Space Physics · Physics 2015-05-14 Mike Hapgood

High contrast coronagraphic imaging of the immediate surrounding of stars requires exquisite control of low-order wavefront aberrations, such as tip-tilt (pointing) and focus. We propose an accurate, efficient and easy to implement…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 Olivier Guyon , Taro Matsuo , Roger Angel

Precise measurements in optical and atomic systems often rely on differential interferometry. This method allows to handle large and correlated phase noise contributions -- such as environmental vibrations, thermal fluctuations, or…

Quantum Physics · Physics 2025-03-25 Luca Pezzè , Andrea Santoni , Chiara Mazzinghi , Marco Fattori , Augusto Smerzi

Measurements of the cosmic 21 cm signal need to achieve a high dynamic range to isolate it from bright foreground emissions. Calibration inaccuracies can compromise the spectral fidelity of the smooth foreground continuum, thereby limiting…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Pascal M. Keller , Bojan Nikolic , Nithyanandan Thyagarajan

A method for estimating the relative content of crystalline phases of a multiphase sample, based on probabilistic analysis of the intensities of the diffraction pattern reflexes, has been developed. The method is based on the introduction…

Materials Science · Physics 2023-11-21 S. V. Gabielkov , I. V. Zhyganiuk , A. D. Skorbun

The knowledge of receiver beam shapes is essential for accurate radio interferometric imaging. Traditionally, this information is obtained by holographic techniques or by numerical simulation. However, such methods are not feasible for an…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sarod Yatawatta

Modern high-sensitivity radio telescopes are discovering an increased number of resolved sources with intricate radio structures and fainter radio emissions. These sources often present a challenge because source detectors might identify…

Instrumentation and Methods for Astrophysics · Physics 2024-06-12 Lara Alegre , Philip Best , Jose Sabater , Huub Rottgering , Martin Hardcastle , Wendy Williams

This paper reported a general noninterferometric high-accuracy quantitative phase imaging (QPI) method for arbitrary complex valued objects. Given by a typical 4f optical configuration as the imaging system, three frames of small-window…

Image and Video Processing · Electrical Eng. & Systems 2021-05-05 Jianhui Huang , An Pan , Huiliang Jin , Guoxiang Meng , Qian Ye

We present an imaging algorithm for polarimetric interferometric data from radio telescopes. It is based on Bayesian statistics and thereby able to provide uncertainties and to incorporate prior information such as positivity of the total…

Instrumentation and Methods for Astrophysics · Physics 2025-04-02 Philipp Arras , Jakob Roth , Martin Reinecke , Richard A. Perley , Andrei Frolov , Rüdiger Westermann , Torsten A. Enßlin

Accurate calibration of internal parameters is a crucial yet challenging prerequisite for 3D reconstruction using light field cameras. In this paper, we propose a linear fractional transformation(LFT) parameter $\alpha$ to decoupled the…

Computer Vision and Pattern Recognition · Computer Science 2025-11-07 Zhong Chen , Changfeng Chen

In radio interferometric observations, the main source of information is the complex visibility function, which includes amplitude and phase. In this paper, the dependence of the phase of the visibility function on the base projection is…

High Energy Astrophysical Phenomena · Physics 2026-01-19 S. V. Chernov

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between the optical and radio positions, it will be important to align the GAIA frame and the International Celestial…

Astrophysics · Physics 2009-11-13 Geraldine Bourda , Patrick Charlot , Richard Porcas , Simon Garrington

Images obtained with single-conjugate adaptive optics (AO) show spatial variation of the point spread function (PSF) due to both atmospheric anisoplanatism and instrumental aberrations. The poor knowledge of the PSF across the field of view…

The separation of cosmological signal from astrophysical foregrounds is a fundamental challenge for any effort to probe the evolution of neutral hydrogen during the Cosmic Dawn and epoch of reionization (EoR) using the 21 cm hyperfine…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-31 Naomi Orosz , Joshua S. Dillon , Aaron Ewall-Wice , Aaron R. Parsons , Nithyanandan Thyagarajan

The paper presents theoretical study of the influence of shape of the spatial spectrum of small-scale ionospheric irregularities on anomalous attenuation of HF radio waves caused by multiple scattering. Several spectrum models are…

Atmospheric and Oceanic Physics · Physics 2007-05-23 Nikolay A. Zabotin , Gennady A. Zhbankov , Eugene S. Kovalenko