Generalized Redundant Calibration of Radio Interferometers

Abstract

Redundant calibration is a technique in radio astronomy that allows calibration of radio arrays whose antennas lie on a lattice by exploiting the fact that redundant baselines should see the same sky signal. Because the number of measured visibilities scales quadratically with the number of antennas but the number of unknowns describing the individual antenna responses and the available information about the sky scales only linearly with the array size, the problem is always over-constrained as long as the array is big and dense enough. This is true even for non-lattice array configurations. In this work we study a generalized algorithm in which a per-antenna gain is replaced with a number of gains. We show that it can successfully fit data from an approximately redundant array on square lattice with pointing and geometry errors, but that the models parameters are difficult to link to the quantities of interest. We discuss the parameterization, limitations, and possible extensions of this algorithm.

arXiv commentVersion accepted by PRD

References in corpus (18)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• The Precision Array for Probing the Epoch of Reionization: 8 Station Results
• How to make maps from CMB data without losing information
• Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
• Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder
• Global, Exact Cosmic Microwave Background Data Analysis Using Gibbs Sampling
• HIRAX: A Probe of Dark Energy and Radio Transients
• Precision Calibration of Radio Interferometers Using Redundant Baselines
• MITEoR: A Scalable Interferometer for Precision 21 cm Cosmology
• Redundant Array Configurations for 21 cm Cosmology
• Mitigating the Effects of Antenna-to-Antenna Variation on Redundant-Baseline Calibration for 21 cm Cosmology
• Redundant-Baseline Calibration of the Hydrogen Epoch of Reionization Array
• Polarized Redundant-Baseline Calibration for 21 cm Cosmology Without Adding Spectral Structure
• The Bias and Uncertainty of Redundant and Sky-Based Calibration under Realistic Sky and Telescope Conditions
• The BINGO telescope: a new instrument exploring the new 21-cm cosmology window
• A Unified Calibration Framework for 21 cm Cosmology
• Patterns of primary beam non-redundancy in close-packed 21 cm array observations
• Brute-Force Mapmaking with Compact Interferometers: A MITEoR Northern Sky Map from 128 MHz to 175 MHz