2011/03/05 by ATA GROUP, Shannon Atkinson, D. C. Backer +68 · 32 citations
Engineering · Physics and Astronomy · #Astronomy #Beam (structure) #Characterization (materials science) #Holography #Optics #Particle Accelerators and Free-Electron Lasers #Physics #Primary (astronomy) #Primary mirror #Radio Astronomy Observations and Technology #Radio astronomy #Radio telescope #Superconducting and THz Device Technology #Telescope #astro-ph.IM
paper · pdf · doi:10.1109/tap.2011.2122214
published in IEEE Transactions on Antennas and Propagation 59(6), 2004-2021 (IEEE Antennas & Propagation Society) · 19 pages, 23 figures, 3 tables, Authors indicated by an double dagger (‡) are affiliated with the SETI Institute, Mountain View, CA 95070. Authors indicated by a section break (§) are affiliated with the Hat Creek Radio Observatory and/or the Radio Astronomy Laboratory, both affiliated with the University of California Berkeley, Berkeley CA
openalex publication_date 2011/03/05 · arxiv created 2012/10/31 · openalex created_date 2016/06/24 · arxiv updated 2018/05/09 · openalex updated_date 2026/08/05
The Allen Telescope Array (ATA) is a cm-wave interferometer in California, comprising 42 antenna elements with 6-m diameter dishes. We characterize the antenna optical accuracy using two-antenna interferometry and radio holography. The distortion of each telescope relative to the average is small, with RMS differences of 1% of beam peak value. Holography provides images of dish illumination, characterizing as-built mirror surfaces. Maximal distortions across ~ 2 meter lengths appear to result from mounting stresses or solar radiation. Experimental RMS errors are 0.7 mm at night and 3 mm under worst-case solar illumination. For frequencies 4, 10, and 15 GHz, the nighttime values indicate sensitivity losses of 1, 10 and 20%, respectively. ATA's wide-bandwidth receiver permits observations over a continuous range 0.5-11.2 GHz. We probe the antenna optical gain and beam pattern stability as a function of focus position and observation frequency, concluding that ATA can produce high fidelity images over a decade of simultaneous observation frequencies. We quantify solar heating effects on antenna sensitivity and pointing accuracy. We find that during the day, observations >;5 GHz will suffer some sensitivity loss and it may be necessary to make antenna pointing corrections on a 1-2 hourly basis.