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RFI mitigation is a critically important issue in radio astronomy using existing instruments as well as in the development of next-generation radio telescopes, such as the Square Kilometer Array (SKA). Most designs for the SKA involve…

Astrophysics · Physics 2015-06-24 N. D. R. Bhat , J. M. Cordes , S. Chatterjee , T. J. W. Lazio

Ground-based 21-cm experiments targeting the global signal from the periods of Cosmic Dawn (CD) and Epoch of Reionization (EoR) are susceptible to adverse effects presented by i) the ionosphere ii) antenna chromaticity induced by objects in…

Instrumentation and Methods for Astrophysics · Physics 2023-08-08 Sonia Ghosh , Mayuri Sathyanarayana Rao , Saurabh Singh

The Square Kilometre Array (SKA) is expected to start science operations in 2030 and by that time there could be up to 10$^5$ artificial satellites in Earth's orbit, comprising an increase of an order of magnitude compared to 2024. Most of…

Instrumentation and Methods for Astrophysics · Physics 2026-04-27 Nicolas Cerardi , Emma Tolley , Federico di Vruno

This paper presents the effects of radio frequency interference (RFI) mitigation on a radio telescope's sensitivity and beam pattern. It specifically explores the impact of subspace-projection mitigation on the phased array feed (PAF) beams…

Instrumentation and Methods for Astrophysics · Physics 2024-05-28 Liroy Lourenco , Aaron P Chippendale

In the past two decades, a rebirth of interest in low-frequency radio astronomy for 21 cm tomography of the Epoch of Reionization, has given rise to a new class of radio interferometers with $N \gg 100$ antennas. The availability of…

Instrumentation and Methods for Astrophysics · Physics 2022-08-11 Deepthi Gorthi

Radio-frequency interference (RFI) presents a significant obstacle to current radio interferometry experiments aimed at the Epoch of Reionization. RFI contamination is often several orders of magnitude brighter than the astrophysical…

Instrumentation and Methods for Astrophysics · Physics 2025-03-05 Jade M. Ducharme , Jonathan C. Pober

Modern interferometric imaging relies on advanced calibration that incorporates direction-dependent effects. Their increasing number of antennas (e.g. in LOFAR, VLA, MeerKAT/SKA) and sensitivity are often tempered with the accuracy of their…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 K. Iheanetu , J. N. Girard , O. Smirnov , K. M. B. Asad , M. de Villiers , K. Thorat , S. Makhathini , R. A. Perley

As a new generation radio telescope, the Allen Telescope Array (ATA) is a prototype for the square kilometer array (SKA). Here we describe recently developed design constraints for the ATA digital signal processing chain as a case study for…

Instrumentation and Methods for Astrophysics · Physics 2012-11-29 G. R. Harp

The design of an interferometric array should allow optimal instrumental response regarding all possible source positions, times of integration and scientific goals. It should also take into account constraints such as forbidden regions on…

Astrophysics · Physics 2009-11-07 F. Boone

Distributed calibration based on consensus optimization is a computationally efficient method to calibrate large radio interferometers such as LOFAR and SKA. Calibrating along multiple directions in the sky and removing the bright…

Instrumentation and Methods for Astrophysics · Physics 2021-10-29 Sarod Yatawatta

Radio frequency interference (RFI) is a significant challenge faced by today's radio astronomers. While most past efforts were devoted to cleaning the RFI from the data, we develop a novel method for categorizing and cataloguing RFI for…

Instrumentation and Methods for Astrophysics · Physics 2023-06-07 Mao Yuan , Weiwei Zhu , Haiyan Zhang , Shijie Huang , Mengyao Xue , Di Li , Youling Yue , Pei Wang , 1 Jiarui Niu , Yuxuan Hu , Chunjiang Li , Chenchen Miao , Yu Wang , Lingqi Meng , Bo Peng

Radio Frequency Interference (RFI) of impulsive nature is created by sources like sparking on high-power transmission lines due to gap or corona discharge and automobile sparking, and it affects the entire observing frequency bands of…

Instrumentation and Methods for Astrophysics · Physics 2023-05-10 Kaushal D. Buch , Ruta Kale , Mekhala Muley , Sanjay Kudale , Ajithkumar B.

In the context of the Laser Interferometer Space Antenna (LISA), the laser subsystems exhibit frequency fluctuations that introduce significant levels of noise into the measurements, surpassing the gravitational wave signal by several…

Instrumentation and Detectors · Physics 2024-01-15 Philipp Euringer , Niklas Houba , Gerald Hechenblaikner , Oliver Mandel , Francis Soualle , Walter Fichter

Radio Frequency Interference (RFI) is emitted from various sources, terrestrial or orbital, and create a nuisance for ground-based 21cm experiments. In particular, single-dish 21cm intensity mapping experiments will be highly susceptible to…

Radio Frequency Interference (RFI), the presence of artificial and/or terrestrial signals in astronomical data, poses a great challenge to the search for pulsars and radio transients, such as Rotating Radio Transients (RRATs) and Fast Radio…

Instrumentation and Methods for Astrophysics · Physics 2026-01-15 R. S. Hombal , L. Levin , B. W. Stappers , M. Droog , A. Karastergiou , D. Lumbaa , M. B. Mickaliger , A. Naidu , K. M. Rajwade , J. Sepulveda , B. Shaw , S. Singh , T. Prabu

Because of the denser active use of the spectrum, and because of radio telescopes higher sensitivity, radio frequency interference (RFI) mitigation has become a sensitive topic for current and future radio telescope designs. Even if quite…

Instrumentation and Methods for Astrophysics · Physics 2017-03-03 Dumez-Viou Cédric , Weber Rodolphe , Ravier Philippe

We investigate the effect of radio-frequency interference (RFI) excision in estimating the cosmological \hi\ 21 cm power spectrum. Flagging of RFI-contaminated channels results in a non-uniform sampling of the instrumental bandpass…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 Arnab Chakraborty , Abhirup Datta , Aishrila Mazumder

Mitigation of radio frequency interference (RFI) is essential to deliver science-ready radio interferometric data to astronomers. In this paper, using dual polarized radio interferometers, we propose to use the polarization information of…

Instrumentation and Methods for Astrophysics · Physics 2020-07-24 Sarod Yatawatta

We present two algorithms to identify and flag radio frequency interference (RFI) in radio interferometric imaging data. The first algorithm utilizes the redundancy of visibilities inside a UV cell in the visibility plane to identify…

Instrumentation and Methods for Astrophysics · Physics 2018-06-27 Srikrishna Sekhar , Ramana Athreya

Radio Frequency Interference (RFI) greatly reduces sensitivity of radio observations to astrophysical signals and creates false positive candidates in searches for radio transients. Real signals are missed while considerable computational…

Instrumentation and Methods for Astrophysics · Physics 2025-10-06 Joseph W. Kania , Kevin Bandura , Duncan R. Lorimer , Richard Prestage