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Modern radio telescopes are favouring densely packed array layouts with large numbers of antennas ($N_\textrm{A}\gtrsim 1000$). Since the complexity of traditional correlators scales as $\mathcal{O}(N_\textrm{A}^2)$, there will be a steep…

Instrumentation and Methods for Astrophysics · Physics 2017-01-20 Nithyanandan Thyagarajan , Adam P. Beardsley , Judd D. Bowman , Miguel F. Morales

The future of radio astronomy will require instruments with large collecting areas for higher sensitivity, wide fields of view for faster survey speeds, and efficient computing and data rates relative to current capabilities. We describe…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 James Kent , Jayce Dowell , Adam Beardsley , Nithyanandan Thyagarjan , Greg Taylor , Judd Bowman

Next generation aperture arrays are expected to consist of hundreds to thousands of antenna elements with substantial digital signal processing to handle large operating bandwidths of a few tens to hundreds of MHz. Conventionally,…

Instrumentation and Methods for Astrophysics · Physics 2023-02-01 Hariharan Krishnan , Adam P. Beardsley , Judd D. Bowman , Jayce Dowell , Matthew Kolopanis , Greg Taylor , Nithyanandan Thyagarajan

The recent demonstration of a real-time direct imaging radio interferometry correlator represents a new capability in radio astronomy. However wide field imaging with this method is challenging since wide-field effects and array…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 James Kent , Adam P. Beardsley , Landman Bester , Steve F. Gull , Bojan Nikolic , Jayce Dowell , Nithyanandan Thyagarajan , Greg B. Taylor , Judd Bowman

Intensive reverberation mapping monitoring programs combine ground-based photometric observations from different telescopes, requiring intercalibration of lightcurves to reduce systematic instrumental differences. We present a new iterative…

Instrumentation and Methods for Astrophysics · Physics 2025-06-02 Roberta Vieliute , Juan V. Hernández Santisteban , Keith Horne , Hannah Cornfield

We introduce a novel direct calibration algorithm to address phase delay, gain, and offset mismatches in Analog-to-Digital Converter (ADC) time interleaving systems. These mismatches, common in high-speed data acquisition, degrade system…

Instrumentation and Methods for Astrophysics · Physics 2025-11-27 Chi-kwan Chan , Hina Suzuki , David Forbes , Andrew Thomas West , Arash Roshanineshat , Daniel P. Marrone , Amy Lowitz

All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and…

Instrumentation and Methods for Astrophysics · Physics 2018-10-09 He Sun , N. Jeremy Kasdin , Robert Vanderbei

Fourier ptychography captures intensity images with varying source patterns (illumination angles) in order to computationally reconstruct large space-bandwidth-product images. Accurate knowledge of the illumination angles is necessary for…

Signal Processing · Electrical Eng. & Systems 2018-11-01 Regina Eckert , Zachary F. Phillips , Laura Waller

Multitude of antennas are typically used in microwave imaging systems. Here we outline a simple and effective calibration method for multiport imaging systems. By using only one additional component, an electronic calibration module (ECal),…

Signal Processing · Electrical Eng. & Systems 2019-05-06 Manuel Kasper , Mykolas Ragulskis , Georg Gramse , Ferry Kienberger

This paper discusses a fast algorithm for analyzing the phases of a multi-tone phase calibration signal. The multi-tone method is superior to its single-tone counterpart. The PCal signal is a wide-band frequency comb derived from an…

Instrumentation and Methods for Astrophysics · Physics 2025-01-13 Jan Wagner , Sergei Pogrebenko

Calibrating out per-antenna signal chain effects is an essential step in analyzing radio interferometric data. For drift-scanning arrays, robustly calibrating the data is especially challenging due to the lack of the ability to track a…

Instrumentation and Methods for Astrophysics · Physics 2026-02-09 Robert Pascua , Jonathan Sievers , Adrian Liu

In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative…

Instrumentation and Methods for Astrophysics · Physics 2016-09-09 Martin Brossard , Mohammed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal , Stefan J. Wijnholds

Radio interferometric imaging aims to estimate an unknown sky intensity image from degraded observations, acquired through an antenna array. In the theoretical case of a perfectly calibrated array, it has been shown that solving the…

Instrumentation and Methods for Astrophysics · Physics 2017-07-25 Audrey Repetti , Jasleen Birdi , Arwa Dabbech , Yves Wiaux

Event cameras triggered a paradigm shift in the computer vision community delineated by their asynchronous nature, low latency, and high dynamic range. Calibration of event cameras is always essential to account for the sensor intrinsic…

Computer Vision and Pattern Recognition · Computer Science 2024-11-26 Mohammed Salah , Abdulla Ayyad , Muhammad Humais , Daniel Gehrig , Abdelqader Abusafieh , Lakmal Seneviratne , Davide Scaramuzza , Yahya Zweiri

The bioinspired event camera, distinguished by its exceptional temporal resolution, high dynamic range, and low power consumption, has been extensively studied in recent years for motion estimation, robotic perception, and object detection.…

Robotics · Computer Science 2025-09-09 Shuolong Chen , Xingxing Li , Liu Yuan

This paper is concerned with algorithms for calibration of direction dependent effects (DDE) in aperture synthesis radio telescopes (ASRT). After correction of Direction Independent Effects (DIE) using self-calibration, imaging performance…

Instrumentation and Methods for Astrophysics · Physics 2017-11-01 S. Bhatnagar , T. J. Cornwell

We present two efficient numerical methods for susceptibility artifact correction applicable in Echo Planar Imaging (EPI), an ultra fast Magnetic Resonance Imaging (MRI) technique widely used in clinical applications. Both methods address a…

Optimization and Control · Mathematics 2016-11-23 Jan Macdonald , Lars Ruthotto

Next generation radio-interferometers, like the Square Kilometre Array, will acquire tremendous amounts of data with the goal of improving the size and sensitivity of the reconstructed images by orders of magnitude. The efficient processing…

Instrumentation and Methods for Astrophysics · Physics 2017-05-26 Alexandru Onose , Arwa Dabbech , Yves Wiaux

The paper reviews progress in imaging in radio interferometry for the period 1993-1996. Unlike an optical telescope, the basic measurements of a radio interferometer (correlations between antennas) are indirectly related to a sky brightness…

Astrophysics · Physics 2007-05-23 R. J. Sault , T. A. Oosterloo

A simple, yet general, formalism for the optimized linear combination of astrophysical images is constructed and demonstrated. The formalism allows the user to combine multiple undersampled images to provide oversampled output at high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Barnaby Rowe , Christopher Hirata , Jason Rhodes
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