2015/01/01 by A. R. Offringa, R. B. Wayth, N. Hurley-Walker +87 · 3 citations
Engineering · Physics and Astronomy · #Astronomy #Astrophysics and Cosmic Phenomena #Computer science #Electromagnetic interference #Environmental science #Geology #Interferometry #LOFAR #Low frequency #Optics #Physics #Radio Astronomy Observations and Technology #Radio Wave Propagation Studies #Radio frequency #Radio telescope #Remote sensing #Telecommunications #astro-ph.IM
paper · pdf · doi:10.1017/pasa.2015.7
Accepted for publication in PASA
openalex publication_date 2015/01/01 · arxiv created 2015/01/16 · arxiv updated 2015/03/12 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Abstract The Murchison Widefield Array is a new low-frequency interferometric radio telescope built in Western Australia at one of the locations of the future Square Kilometre Array. We describe the automated radio-frequency interference detection strategy implemented for the Murchison Widefield Array, which is based on the aoflagger platform, and present 72–231 MHz radio-frequency interference statistics from 10 observing nights. Radio-frequency interference detection removes 1.1% of the data. Radio-frequency interference from digital TV is observed 3% of the time due to occasional ionospheric or atmospheric propagation. After radio-frequency interference detection and excision, almost all data can be calibrated and imaged without further radio-frequency interference mitigation efforts, including observations within the FM and digital TV bands. The results are compared to a previously published Low-Frequency Array radio-frequency interference survey. The remote location of the Murchison Widefield Array results in a substantially cleaner radio-frequency interference environment compared to Low-Frequency Array’s radio environment, but adequate detection of radio-frequency interference is still required before data can be analysed. We include specific recommendations designed to make the Square Kilometre Array more robust to radio-frequency interference, including: the availability of sufficient computing power for radio-frequency interference detection; accounting for radio-frequency interference in the receiver design; a smooth band-pass response; and the capability of radio-frequency interference detection at high time and frequency resolution (second and kHz-scale respectively).