The Murchison Widefield Array: Design Overview

TL;DR

The Murchison Widefield Array (MWA) is a low-frequency radio telescope designed for diverse scientific investigations, featuring a large array of dipoles with advanced calibration and imaging capabilities in a radio-quiet environment.

Contribution

This paper presents the design and technical overview of the MWA, highlighting its innovative array configuration, calibration methods, and suitability for key scientific projects.

Findings

High-quality uv coverage and PSF due to array design

Real-time calibration with novel algorithms

Capability to study Epoch of Reionization and solar phenomena

Abstract

The Murchison Widefield Array (MWA) is a dipole-based aperture array synthesis telescope designed to operate in the 80-300 MHz frequency range. It is capable of a wide range of science investigations, but is initially focused on three key science projects. These are detection and characterization of 3-dimensional brightness temperature fluctuations in the 21cm line of neutral hydrogen during the Epoch of Reionization (EoR) at redshifts from 6 to 10, solar imaging and remote sensing of the inner heliosphere via propagation effects on signals from distant background sources,and high-sensitivity exploration of the variable radio sky. The array design features 8192 dual-polarization broad-band active dipoles, arranged into 512 tiles comprising 16 dipoles each. The tiles are quasi-randomly distributed over an aperture 1.5km in diameter, with a small number of outliers extending to 3km. All tile-tile baselines are correlated in custom FPGA-based hardware, yielding a Nyquist-sampled instantaneous monochromatic uv coverage and unprecedented point spread function (PSF) quality. The correlated data are calibrated in real time using novel position-dependent self-calibration algorithms. The array is located in the Murchison region of outback Western Australia. This region is characterized by extremely low population density and a superbly radio-quiet environment,allowing full exploitation of the instrumental capabilities.