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The tens of millions of radio sources to be detected with next-generation surveys pose new challenges, quite apart from the obvious ones of processing speed and data volumes. For example, existing algorithms are inadequate for source…

Instrumentation and Methods for Astrophysics · Physics 2017-06-14 Ray P. Norris

In this paper we discuss the issue of loosing telemetry (TM) data due to different reasons (e.g. spacecraft-ground transmissions) while performing a full-sky survey with space-borne instrumentation. This is a particularly important issue…

Astrophysics · Physics 2009-11-07 D. Maino , C. Burigana , F. Pasian

The new generation of radio telescopes, such as the Square Kilometer Array (SKA), requires dramatic advances in computer hardware and software, in order to process the large amounts of produced data efficiently. In this document, we explore…

Instrumentation and Methods for Astrophysics · Physics 2015-04-15 Matthias Petschow

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 detection and flagging is one of the most difficult and urgent problems in 21 cm Epoch of Reionization research. In this work, we present $\chi^2$ from redundant calibration as a novel method for RFI detection…

Instrumentation and Methods for Astrophysics · Physics 2024-08-28 Theodora Kunicki , Jonathan C. Pober

Multi-photon dressing and interference in atomic systems is a key to several cutting edge technologies like Rydberg atom radio frequency sensors, clocks and magnetometers because it enables the engineering of atomic properties. Rydberg atom…

This study investigates some of the consequences of representing the sky by a rectangular grid of pixels on the dynamic range of images derived from radio interferometric measurements. In particular, the effects of image pixelization…

Astrophysics · Physics 2009-11-13 W. D. Cotton , Juan M. Uson

The basic principle of astronomical interferometry is to derive the angular distribution of radiation in the sky from the Fourier transform of the electric field on the ground. What is so special about the Fourier transform? Nothing, it…

Instrumentation and Methods for Astrophysics · Physics 2015-01-30 Brian C. Lacki

We present a new approach to multi-frequency synthesis in radio astronomy. Using Bayesian inference techniques, the new technique estimates the sky brightness and the spectral index simultaneously. In principle, the bandwidth of a wide-band…

Instrumentation and Methods for Astrophysics · Physics 2015-09-16 H. Junklewitz , M. A. Bell , T. Enßlin

The sensitivity of radio telescopes is becoming increasingly limited by the presence of radio frequency interference (RFI), which will worsen as the radio spectrum becomes more crowded. One context where this poses a challenge is the field…

The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

Conventional techniques that measure rapid time variations are inefficient or inadequate to discover and observe rapidly pulsating astronomical sources. It is therefore conceivable that there exist some classes of objects pulsating with…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Ermanno F Borra

Redshifted 21 cm radiation originating from the cosmological distribution of neutral hydrogen (HI) appears as a background radiation in low frequency radio observations. The angular and frequency domain fluctuations in this radiation carry…

Astrophysics · Physics 2007-05-23 Somnath Bharadwaj , SK. Saiyad Ali

Hydrogen intensity mapping is a new field in astronomy that promises to make three-dimensional maps of the matter distribution of the Universe using the redshifted $21\,\textrm{cm}$ line of neutral hydrogen gas (HI). Several ongoing and…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Anh Phan , Santanu Das , Albert Stebbins , Peter Timbie , Reza Ansari , Shifan Zuo , Jixia Li , Trevor Oxholm , Fengquan Wu , Xuelei Chen , Shijie Sun , Yougang Wang , Jiao Zhang

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

The fidelity of radio astronomical images is generally assessed by practical experience, i.e. using rules of thumb, although some aspects and cases have been treated rigorously. In this paper we present a mathematical framework capable of…

Instrumentation and Methods for Astrophysics · Physics 2010-03-12 Stefan J. Wijnholds , Alle-Jan van der Veen

Synthetic aperture radar is a high-resolution two-dimensional imaging radar, however, during the imaging process, SAR is susceptible to intentional and unintentional interference, with radio frequency interference (RFI) being the most…

Signal Processing · Electrical Eng. & Systems 2024-03-06 Fuping Fang , Wenhao Lv , Dahai Dai

Narrowband radio search for extraterrestrial intelligence (SETI) in the 21st century suffers severely from radio frequency interference (RFI), resulting in a high number of false positives, and it could be the major reason why we have not…

Instrumentation and Methods for Astrophysics · Physics 2023-11-20 Bo-Lun Huang , Zhen-Zhao Tao , Tong-Jie Zhang

We investigate the effectiveness of the statistical radio frequency interference (RFI) mitigation technique spectral kurtosis (SK) in the face of simulated realistic RFI signals. SK estimates the kurtosis of a collection of M power values…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Evan T. Smith , Ryan Lynch , D. J. Pisano