Distributed Radio Interferometric Calibration

TL;DR

This paper introduces a distributed calibration method for radio interferometry that leverages frequency parallelism and smoothness to enhance computational efficiency and robustness, demonstrated through simulation results.

Contribution

It proposes a novel distributed calibration approach that uses consensus optimization and data parallelism to improve efficiency and robustness in radio astronomical data calibration.

Findings

Distributed calibration reduces computational load.

Enhanced robustness against calibration errors.

Simulation confirms feasibility and advantages.

Abstract

Increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. In this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. We exploit the data parallelism across frequency that is inherent in radio astronomical observations that are recorded as multiple channels at different frequencies. Moreover, we also exploit the smoothness of the variation of calibration parameters across frequency. Data parallelism enables us to distribute the computing load across a network of compute agents. Smoothness in frequency enables us reformulate calibration as a consensus optimization problem. With this formulation, we enable flow of information between compute agents calibrating data at different frequencies, without actually passing the data, and thereby improving robustness. We present simulation results to show the feasibility as well as the advantages of distributed calibration as opposed to conventional calibration.