The Effects of the Local Environment on a Compact Radio Interferometer I: Cross-Coupling in the Tianlai Dish Pathfinder Array
[1];
[1];
[1];
- Univ. of Wisconsin, Madison, WI (United States)
- Centre National de la Recherche Scientifique (CNRS) (France); Univ. Paris-Sud, Orsay (France)
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
- Chinese Academy of Sciences (CAS), Beijing (China)
- Chinese Academy of Sciences (CAS), Beijing (China); University of Chinese Academy of Sciences, Beijing (China); Peking Univ., Beijing (China)
- Chinese Academy of Sciences (CAS), Beijing (China); University of Chinese Academy of Sciences, Beijing (China)
The visibilities measured by radio astronomical interferometers include non-astronomical correlated signals that arise from the local environment of the array. These correlated signals are especially important in compact arrays such as those under development for 21cm intensity mapping. The amplitudes of the contaminated visibilities can exceed the expected 21cm signal and represent a significant systematic effect. We study the receiver noise radiated by antennas in compact arrays and develop a model for how it couples to other antennas. We apply the model to the Tianlai Dish Pathfinder Array (TDPA), a compact array of 16, 6-m dish antennas. The coupling model includes electromagnetic simulations, measurements with a network analyzer, and measurements of the noise of the receivers. We compare the model to drift-scan observations with the array and set requirements on the level of antenna cross-coupling for 21cm intensity mapping instruments. Here, we find that for the TDPA, cross-coupling would have to be reduced by three orders of magnitude in order to contribute negligibly to the visibilities.
- Research Organization:
- Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- Grant/Contract Number:
- AC02-07CH11359
- OSTI ID:
- 2283754
- Report Number(s):
- FERMILAB-PUB--23-673-CSAID-T; arXiv:2311.03494; oai:inspirehep.net:2719934
- Journal Information:
- Journal of Astronomical Instrumentation, Journal Name: Journal of Astronomical Instrumentation Journal Issue: 1 Vol. 13; ISSN 2251-1717
- Publisher:
- World Scientific PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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