English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The advent of a new generation of low frequency interferometers has opened adirect window into the Epoch of Reionisation (EoR). However, key to a detectionof the faint 21-cm signal, and reaching the sensitivity limits of these arrays,is a detailed understanding of the instruments and their calibration. In thiswork we use simulations to investigate the bias and uncertainty of redundancybased calibration. Specifically, we study the influence of the fluxdistribution of the radio sky and the impact of antenna position offsets on thecomplex calibration solutions. We find that the position offsets introduce abias into the phase component of the calibration solutions. This phase biasincreases with the distance between bright radio sources and the pointingcenter, and with the flux density of these sources. This is potentiallyproblematic for redundant calibration on MWA observations of EoR fields 1 and2. EoR field 0, however, lacks such sources. We also compared the simulationswith theoretical estimates for the bias and uncertainty in sky model basedcalibration on incomplete sky models for the redundant antenna tiles in theMWA. Our results indicate that redundant calibration outperforms sky basedcalibration due to the high positional precision of the MWA antenna tiles.

The Bias and Uncertainty of Redundant and Sky-Based Calibration under Realistic Sky and Telescope Conditions