A5073318796- Radio Astronomy Observations and Technology
- Antenna Design and Optimization
- Astro and Planetary Science
- Planetary Science and Exploration
- Gamma-ray bursts and supernovae
- Space Satellite Systems and Control
- Astrophysics and Cosmic Phenomena
- Ionosphere and magnetosphere dynamics
- Pulsars and Gravitational Waves Research
- GNSS positioning and interference
- Electromagnetic Compatibility and Measurements
- Radio Wave Propagation Studies
- Solar and Space Plasma Dynamics
- Space exploration and regulation
- Astrophysical Phenomena and Observations
- Superconducting and THz Device Technology
- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- Spacecraft Design and Technology
- Soil Moisture and Remote Sensing
- Astronomy and Astrophysical Research
- Radar Systems and Signal Processing
- Space Science and Extraterrestrial Life
- Stellar, planetary, and galactic studies
- Atmospheric Ozone and Climate
Istituto di Radioastronomia di Bologna
2015-2024
National Institute for Astrophysics
2013-2022
Arcetri Astrophysical Observatory
2018-2021
Institute of Radio Astronomy
2013-2019
National Academies of Sciences, Engineering, and Medicine
2005-2011
Osservatorio Astrofisico di Torino
2009-2010
University of Salento
2009
Fast radio bursts (FRBs) are short (millisecond) pulses originating from enigmatic sources at extragalactic distances so far lacking a detection in other energy bands. Magnetized neutron stars (magnetars) have been considered as the powering FRBs, but connection is controversial because of differing energetics and lack X-ray detections with similar characteristics two classes. We report here by AGILE satellite on April 28, 2020 an burst coincidence very bright Galactic magnetar SGR...
In this paper we present the electromagnetic modeling and beam pattern measurements of a 16-elements ultra wideband sparse random test array for low frequency instrument Square Kilometer Array telescope. We discuss importance small platform development technologies techniques towards final telescope, highlighting most relevant aspects its design. also describe simulations work as well embedded-element using an Unmanned Aerial Vehicle system. The latter are helpful both validation models...
Abstract We report on the lowest-frequency detection to date of three bursts from fast radio burst FRB 180916.J0158+65, observed at 328 MHz with Sardinia Radio Telescope (SRT). The SRT periodic repeater 180916.J0158+65 for five days 2020 February 20 24 during a time interval active bursting, and detected first hour observations; no more were remaining ∼30 hr. Simultaneous observations 1548 did not detect any bursts. Burst fluences are in range 37 13 Jy ms. No relevant scattering is these...
ABSTRACT Magnetars are a promising candidate for the origin of fast radio bursts (FRBs). The detection an extremely luminous burst from Galactic magnetar SGR J1935+2154 on 2020 April 28 added credence to this hypothesis. We report simultaneous and non-simultaneous observing campaigns using Arecibo, Effelsberg, LOFAR, MeerKAT, MK2, Northern Cross telescopes MeerLICHT optical telescope in days months after event. did not detect any significant single pulses down fluence limits between 25 mJy...
Fast radio bursts (FRBs) are millisecond transients observed at cosmological distances. The nature of their progenitors is still a matter debate, although magnetars invoked by most models. proposed FRB-magnetar connection was strengthened the discovery an FRB-like event from Galactic magnetar SGR J1935+2154. In this work, we aim to investigate how prevalent such as J1935+2154 within FRB progenitors. We carried out search in sample seven nearby (< 12 Mpc) galaxies with Northern Cross...
Modern radio astronomical facilities in the Very High-Frequency band (VHF, 30-300 MHz) consist of large antenna arrays with digital beamforming. The calibration these instruments requires accurate models their electromagnetic behavior. Numerical covering full telescope field-of-view are nowadays effectively computed by means full-wave solvers. However, experimental verification is still an open and challenging task. This letter proposes a strategy based on near-field scans. An unmanned...
Front-end amplifiers with high input impedance are exploited to build active array elements for modern low-frequency radio telescopes. The combination of such loading and mutual coupling between adjacent is responsible the deep nulls that present in some embedded element patterns (EEPs) Low-Frequency Array. This paper quantifies this phenomenon both models experimental data. full-wave simulations measured amplifier scattering parameters combined obtain EEP models. These good agreement situ...
The design and development process for the Square Kilometre Array (SKA) radio telescope’s Low Frequency Aperture component was progressed during SKA pre-construction phase by an international consortium, with goal of meeting requirements a critical review. As part full-sized prototype ‘station’ deployed – Verification System 1 (AAVS1). We provide system overview describe commissioning results AAVS1, which is low frequency telescope 256 dual-polarisation log-periodic dipole antennas working...
The low frequency component of the Square Kilometre Array (SKA1-Low) will be an aperture phased array located at Murchison Radio-astronomy Observatory (MRO) site in Western Australia. It composed 512 stations, each consisting 256 log-periodic dual-polarized antennas, and operate range (50 to 350 MHz) SKA bandwidth. Aperture Verification System 2 (AAVS2), operational since late 2019, is last full-size engineering prototype station deployed MRO before start SKA1-Low construction phase. aim...
Context. The Sun is an extraordinary workbench, on which several fundamental astronomical parameters can be measured with high precision. Among these parameters, the solar radius R ⊙ plays important role in aspects, for instance, evolutionary models. Moreover, it conveys information about structure of different layers that compose interior and its atmosphere. Despite efforts to obtain accurate measurements , subject still debated, are puzzling and/or lacking many frequency ranges. Aims. We...
Context. Fast radio bursts (FRBs) are energetic, millisecond-duration pulses observed at extragalactic distances and whose origins still a subject of heated debate. A fraction the FRB population have shown repeating bursts, however it’s unclear whether these represent distinct class sources. Aims. We investigated bursting behaviour 20220912A, one most active FRBs known thus far. In particular, we focused on its burst energy distribution, linked to source energetics, emission spectrum, with...
A novel antenna pattern measurement technique has been recently developed exploiting the capabilities of a micro Unmanned Aerial Vehicle (UAV) as far-field test-source. This is suitable for characterizing VHF antennas such those low-frequency radio astronomy. paper presents some measurements performed on Square Kilometer Array Log-periodic Antenna (SKALA), which selected receiving element Low Frequency Aperture (LFAA).
Abstract This paper describes two small aperture array demonstrators called Medicina and Sardinia Array Demonstrators (MAD SAD, respectively). The objectives of these instruments are to acquire experience test new technologies for a possible application the low‐frequency telescope Square Kilometer phase 1 (SKA1‐LOW). MAD was concluded in 2014, it turned out be an important bench implementing calibration techniques based on artificial source mounted aerial vehicle. SAD is 128 dual‐polarized...
A signal processing hardware platform has been developed for the Low Frequency Aperture Array component of Square Kilometre (SKA). The board, called an Analog Digital Unit (ADU), is able to acquire and digitize broadband (up 500[Formula: see text]MHz bandwidth) radio-frequency streams from 16 dual polarized antennas, channel data then combine them flexibly as part a larger beamforming system. It envisaged that there will be more than 8000 these platforms in first phase SKA, so particular...
The Square Kilometre Array telescope at low-frequency (SKA-Low) will be a phased array supporting wide range of science cases covering the frequency band 50 - 350 MHz, while same time asking for high sensitivity and excellent characteristics. These extremely challenging requirements resulted in design using 512 groups 256 log periodic dual polarized antennas each (where group is called "station"), total 131072 antennas. stations are randomly distributed mostly within dense area around centre...
The characterization of VHF and UHF antennas is very challenging owing to the low-operative frequency. This paper presents a novel technique (originally developed for radio-astronomical applications) that can be suitable measure ground-based aerospace in real installation conditions, with an accurate cost-effective method which does not require additional infrastructures. system mainly consists micro Unmanned Aerial Vehicle (UAV), equipped both RF transmitter antenna, properly designed...
This paper overviews the emerging antenna and EM field measurement strategies based on modern Unmanned Aerial Vehicle (UAV) technology. UAVs are currently being exploited as source/probe positioners in various applications from HF to microwaves. Several contributions all-over world will be discussed terms of approach, RF setup positioning strategies. A example at 350 MHz highlights importance position orientation accuracy post-processing chain.
The Unmanned Aerial Vehicle (UAV) technology has been recently used to develop a pattern measurement system for low-frequency arrays in their real installation conditions. This paper presents the most important results that have obtained on Italian Medicina Array Demonstrator (MAD).
This paper deals with the electromagnetic modeling of a dipole antenna mounted on micro Unmanned Aerial Vehicle (UAV). Such setup has been recently used as test source to characterize radiation pattern fairly large VHF and UHF antennas in their installation conditions i.e. ground, adjacent elements. In this framework, an accurate is fundamental distinguish properly its characteristics from those under test. The computed results are verified both reflection coefficient measurements showing...
Low frequency aperture array technology requires advanced ad-hoc tools for performing antenna and pattern characterization instrumental calibration. A micro Unmanned Aerial Vehicle (UAV) mounting a radio-frequency transmitting system developed in Italy has demonstrated to satisfy the challenging characteristics of these tasks. Therefore, measurement campaign by means this UAV been planned one Dutch station Frequency Array (LOFAR) with main goal improve LOFAR models. In preparation campaign,...
Fast radio bursts remain one of the most enigmatic astrophysical sources. Observations have significantly progressed over last few years, thanks to capabilities new telescopes and refurbishment existing ones. Here we describe upgrade Northern Cross telescope, operating in 400-416~MHz frequency band, with ultimate goal turning array into a dedicated instrument survey sky for fast bursts. We present test observations pulsar B0329+54 characterize system performance forecast detectability....