Kavli Affiliate: Jacqueline Hewitt
| First 5 Authors: Vincent MacKay, Vincent MacKay, , ,
| Summary:
We introduce the Radio-array $uv$ Layout Engineering Strategy (RULES), an
algorithm for designing radio arrays that achieve complete coverage of the $uv$
plane, defined as, at minimum, regular sampling at half the observing
wavelength ($lambda$) along the $u$ and $v$ axes within a specified range of
baseline lengths. Using RULES, we generate $uv$-complete layouts that cover the
range $10lambdaleq|(u,v)|leq 100lambda$ with fewer than 1000 antennas of
diameter $5lambda$, comparable to current and planned arrays. We demonstrate
the effectiveness of such arrays for mitigating contamination from bright
astrophysical foregrounds in 21 cm Epoch of Reionization
observations,particularly in the region of Fourier space known as the
foreground wedge,by simulating visibilities of foreground-like sky models over
the 130-150 MHz band and processing them through an image-based power spectrum
estimator. We find that with complete $uv$ coverage, the wedge power is
suppressed by sixteen orders of magnitude compared to an array with a compact
hexagonal layout (used as a reference for a sparse $uv$ coverage). In contrast,
we show that an array with the same number of antennas but in a random
configuration only suppresses the wedge by three orders of magnitude, despite
sampling more distinct $uv$ points over the same range. We address real-world
challenges and find that our results are sensitive to small antenna position
errors and missing baselines, while still performing equally or significantly
better than random arrays in any case. We propose ways to mitigate those
challenges such as a minimum redundancy requirement or tighter $uv$ packing
density.
| Search Query: ArXiv Query: search_query=au:”Jacqueline Hewitt”&id_list=&start=0&max_results=3