Related papers: Antenna array characterization via radio interfero…

Radio Frequency Interference (RFI) presents a significant challenge for carrying out precision measurements in radio astronomy. In particular, RFI can be a showstopper when looking for faint cosmological signals such as the red-shifted…

This paper discusses an outdoor test facility for the noise characterization of active antenna arrays, using measurement results of array noise temperatures in the order of 50 K for a number of small aperture arrays. The measurement results…

The origin and evolution of structure in the Universe could be studied in the Dark Ages. The highly redshifted HI signal between 30 < z < 80 is the only observable signal from this era. Human radio interference and ionospheric effects limit…

FarView is a proposed low frequency radio interferometer for deployment on the lunar far side, enabled by the Moon's radio quiet environment. Operating over 1-50 MHz inaccessible from Earth, FarView will open a new observational window and…

The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large scale and compact emission. It is, however, very challenging to synthesize thermal noise…

Knowledge of the population of radio sources in the range ~2-200 GHz is important for understanding their effects on measurements of the Cosmic Microwave Background power spectrum. We report measurements of the 30 GHz flux densities of 605…

The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution. To advance this research, countries have made significant investments in constructing large low-frequency radio…

Detecting primordial fluctuations from the cosmic dark ages requires extremely large low-frequency radio telescope arrays deployed on the far side of the Moon. The antenna of such an array must be lightweight, easily storable and…

This paper presents the CosmicWeb-21cm array, a novel radio interferometer designed to overcome the key challenges in 21 cm cosmology. Its core innovations include: (1) a multi-scale nested geometry combining a hexagonal core with…

The Low Frequency Array (LOFAR) is uniquely able to perform deep, 15" resolutions imaging at frequencies below 100 MHz. Observations in this regime, using the Low Band Antenna (LBA) system, are significantly affected by instrumental and…

The emission from neutral hydrogen (HI) clouds in the post-reionization era (z < 6), too faint to be individually detected, is present as a diffuse background in all low frequency radio observations below 1420 MHz. The angular and frequency…

Ground based low frequency radio interferometers have been developed in the last decade and are providing the scientific community with high quality observations. Conversely, current radioastronomy instruments in space have a poor angular…

Cosmological observations from ground at millimetre and sub-millimetre wavelengths are affected by atmospheric absorption and consequent emission. The low and high frequency (sky noise) fluctuations of atmospheric performance imply careful…

We propose a new algorithm, for parameter estimation that is applicable to imaging using moving and synthetic aperture arrays. The new method results in higher resolution and more accurate estimation than commonly used methods when strong…

We characterize the low frequency radio-frequency interference (RFI) environment at the Murchison Radio-astronomy Observatory (MRO), the location selected for the low-frequency component of the Square Kilometre Array. Data were collected…

The Submillimeter Array (SMA), a collaboration between the Smithsonian Astrophysical Observatory and the Academica Sinica Institute for Astronomy and Astrophysics of Taiwan, is an eight-element radio-interferometer designed to operate…

Radio-interferometry (RI) observes the sky at unprecedented angular resolutions, enabling the study of several far-away galactic objects such as galaxies and black holes. In RI, an array of antennas probes cosmic signals coming from the…

In this paper, we investigate methods for interference location in satellite communication system using satellite multi-beam antenna with subspace based schemes. A novel MUSIC based approach is proposed for estimating the direction of…

A measurement of the cosmological 21 cm signal remains a promising but as-of-yet unattained ambition of radio astronomy. A positive detection would provide direct observations of key unexplored epochs of our cosmic history, including the…

Atmospheric water vapor causes significant undesired phase fluctuations for the Submillimeter Array (SMA) interferometer, particularly in its highest frequency observing band of 690 GHz. One proposed solution to this atmospheric effect is…