Related papers: Systematic effects in LOFAR data: A unified calibr…

A fraction of galaxy clusters harbor diffuse radio sources known as radio halos. The currently adopted scenario for their formation is based on second-order Fermi re-acceleration of seed electrons that is driven by merger-driven turbulence…

Carrier frequency offset estimation (CFOE) is a critical stage in modern coherent optical communication systems. Although conventional all-digital techniques perform reliably in typical fiber-optic communication links, CFOE often becomes a…

Producing ultra-deep high-angular-resolution images with current and next-generation radio interferometers introduces significant computational challenges. In particular, the imaging is so demanding that processing large datasets,…

We use numerical simulations of cosmic reionization and radiative processes related to the HI 21 cm emission line to produce synthetic radio maps as seen by next generation radio telescopes that will operate at low radio frequencies (e.g.…

The aim of the LOFAR Epoch of Reionization (EoR) project is to detect the spectral fluctuations of the redshifted HI 21cm signal. This signal is weaker by several orders of magnitude than the astrophysical foreground signals and hence, in…

Aims. With the recent preliminary release of the LOFAR LBA Sky Survey (LoLSS), the first wide-area, ultra-low frequency observations from LOFAR were published. Our aim is to combine this data set with other surveys at higher frequencies to…

Understanding the temporal characteristics of data from low frequency radio telescopes is of importance in devising suitable calibration strategies. Application of time series analysis techniques to data from radio telescopes can reveal a…

High power in narrow frequency bands, spectral lines, are a feature of an interferometric gravitational wave detector's output. Some lines are coherent between interferometers, in particular, the 2 km and 4 km LIGO Hanford instruments. This…

Low-frequency spectral studies of radio pulsars represent a key method for uncovering their emission mechanisms, magnetospheric structure, and signal interactions with the surrounding interstellar medium (ISM). In recent years, more…

Precision phase readout of optical beat note signals is one of the core techniques required for intersatellite laser interferometry. Future space based gravitational wave detectors like eLISA require such a readout over a wide range of MHz…

Radio astronomy is entering a new era with new and future radio observatories such as the Low Frequency Array and the Square Kilometer Array. We describe in detail an automated flagging pipeline and evaluate its performance. With only a…

Systematic effects arising from cosmic rays have been shown to be a significant threat to space telescopes using high-sensitivity bolometers. The LiteBIRD space mission aims to measure the polarised Cosmic Microwave Background with…

The Planck mission will provide full-sky maps of the Cosmic Microwave Background with unprecedented angular resolution (~ 10') and sensitivity (DT / T = 10^-6). This requires cryogenically cooled, high sensitivity detectors as well as an…

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…

Calibration of radio interferometric observations becomes increasingly difficult towards lower frequencies. Below ~300 MHz, spatially variant refractions and propagation delays of radio waves traveling through the ionosphere cause phase…

Radio-frequency interference (RFI) is a major systematic limitation in radio astronomy, particularly for science cases requiring high sensitivity, such as 21 cm cosmology. Traditionally, RFI is dealt with by identifying its signature in the…

AIMS: To demonstrate and test the capability of the next generation of low-frequency radio telescopes to perform high resolution observations across intra-continental baselines. Jupiter's strong burst emission is used to perform broadband…

The calibration of modern radio interferometers is a significant challenge, specifically at low frequencies. In this perspective, we propose a novel iterative calibration algorithm, which employs the popular sparse representation framework,…

Context: Phase referencing is a standard calibration technique in radio interferometry, particularly suited for the detection of weak sources close to the sensitivity limits of the interferometers. However, effects from a changing…

The redshifted 21 cm brightness distribution from neutral hydrogen is a promising probe into the cosmic dark ages, cosmic dawn, and re-ionization. LOFAR's Low Band Antennas (LBA) may be used in the frequency range 45 MHz to 85 MHz (30>z>16)…