Further evaluation of bootstrap resampling as a tool for radio-interferometric imaging fidelity assessment

TL;DR

This paper evaluates bootstrap resampling methods for pixel-level imaging fidelity assessment in radio interferometry, demonstrating their promising statistical performance and providing practical guidelines for their application in complex imaging scenarios.

Contribution

It extends previous evaluations of bootstrap methods to a broader domain, including diverse source morphologies and brightness distributions, for improved imaging fidelity assessment.

Findings

Bootstrap methods show strong potential for interferometric imaging fidelity assessment.

Both model-based and subsample bootstrap methods perform well across a broader domain.

Guidelines for practical application of bootstrap methods are provided.

Abstract

We report on a broader evaluation of statistical bootstrap resampling methods as a tool for pixel-level calibration and imaging fidelity assessment in radio interferometry. Pixel-level imaging fidelity assessment is a challenging problem, important for the value it holds in robust scientific interpretation of interferometric images, enhancement of automated pipeline reduction systems needed to broaden the user community for these instruments, and understanding leadingedge direction-dependent calibration and imaging challenges for future telescopes such as the Square Kilometer Array. This new computational approach is now possible because of advances in statistical resampling for data with long-range dependence and the available performance of contemporary high-performance computing resources. We expand our earlier numerical evaluation to span a broader domain subset in simulated image fidelity and source brightness distribution morphologies. As before, we evaluate the statistical performance of the bootstrap resampling methods against direct Monte Carlo simulation. We find both model-based and subsample bootstrap methods to continue to show significant promise for the challenging problem of interferometric imaging fidelityassessment, when evaluated over the broader domain subset. We report on their measured statistical performance and guidelines for their use and application in practice. We also examine the performance of the underlying polarization self-calibration algorithm used in this study over a range of parallactic angle coverage.