Baseline Dependent Averaging in Radio Interferometry

TL;DR

This paper analyzes baseline dependent averaging (BDA) in radio interferometry, showing it reduces data volume significantly without loss of information, verified through simulations, and is applicable to large arrays like SKA.

Contribution

It provides a theoretical and empirical validation of BDA's effectiveness and safety in modern radio interferometry, enabling substantial data volume reduction.

Findings

BDA causes a well-defined decorrelation loss.

Theoretical expressions for decorrelation are derived.

Simulations confirm BDA's reliability and efficiency.

Abstract

This paper presents a detailed analysis of the applicability and benefits of baseline dependent averaging (BDA) in modern radio interferometers and in particular the Square Kilometre Array (SKA). We demonstrate that BDA does not affect the information content of the data other than a well-defined decorrelation loss for which closed form expressions are readily available. We verify these theoretical findings using simulations. We therefore conclude that BDA can be used reliably in modern radio interferometry allowing a reduction of visibility data volume (and hence processing costs for handling visibility data) by more than 80%.