Effects of model incompleteness on the drift-scan calibration of radio telescopes
ABSTRACT Precision calibration poses challenges to experiments probing the redshifted 21-cm signal of neutral hydrogen from the Cosmic Dawn and Epoch of Reionization (z ∼ 30–6). In both interferometric and global signal experiments, systematic calibration is the leading source of error. Though many aspects of calibration have been studied, the overlap between the two types of instruments has received less attention. We investigate the sky based calibration of total power measurements with a HERA dish and an EDGES-style antenna to understand the role of autocorrelations in the calibration of an interferometer and the role of sky in calibrating a total power instrument. Using simulations we study various scenarios such as time variable gain, incomplete sky calibration model, and primary beam model. We find that temporal gain drifts, sky model incompleteness, and beam inaccuracies cause biases in the receiver gain amplitude and the receiver temperature estimates. In some cases, these biases mix spectral structure between beam and sky resulting in spectrally variable gain errors. Applying the calibration method to the HERA and EDGES data, we find good agreement with calibration via the more standard methods. Although instrumental gains are consistent with beam and sky errors similar in scale to those simulated, more »
Authors:
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Award ID(s):
Publication Date:
NSF-PAR ID:
10300464
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
506
Issue:
3
Page Range or eLocation-ID:
4578 to 4592
ISSN:
0035-8711
National Science Foundation
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2. ABSTRACT

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3. Abstract

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5. ABSTRACT

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