The Aperture Array Verification System 1: System overview and early commissioning results

¹ ASTRON, Dwingeloo, The Netherlands
e-mail: benthem@astron.nl
² ICRAR/Curtin University, Perth, Australia
³ INAF/IRA – Institute of RadioAstronomy, Bologna, Italy
⁴ INAF – Osservatorio Astronomico di Arcetri, Florence, Italy
⁵ INAF – Istituto di Astrofisica Spaziale e Fisica Cosmica, Milan, Italy
⁶ INAF – Osservatorio Astronomico di Catania, Catania, Italy
⁷ INAF – Headquarter, Rome, Italy
⁸ CNR-IEIIT, Turin, Italy
⁹ Bologna University DEI, Bologna, Italy
¹⁰ University of Florence DINFO, Florence, Italy
¹¹ Institute of Space Sciences and Astronomy, University of Malta, Msida, Malta
¹² University of Cambridge, Cambridge, UK
¹³ University of Oxford, Oxford, UK
¹⁴ SKA Organization HQ – Jodrell Bank, Cheshire, UK
¹⁵ ATC/STFC, Edinburgh, Scotland, UK

Received: 8 December 2020
Accepted: 22 September 2021

Abstract

The design and development process for the Square Kilometre Array (SKA) radio telescope’s Low Frequency Aperture Array component was progressed during the SKA pre-construction phase by an international consortium, with the goal of meeting requirements for a critical design review. As part of the development process a full-sized prototype SKA Low ‘station’ was deployed – the Aperture Array Verification System 1 (AAVS1). We provide a system overview and describe the commissioning results of AAVS1, which is a low frequency radio telescope with 256 dual-polarisation log-periodic dipole antennas working as a phased array. A detailed system description is provided, including an in-depth overview of relevant sub-systems, ranging from hardware, firmware, software, calibration, and control sub-systems. Early commissioning results cover initial bootstrapping, array calibration, stability testing, beam-forming, and on-sky sensitivity validation. Lessons learned are presented, along with future developments.