Frequency Averaging Effect on SKA1-LOW Image Based on Simulation

Abstract

SKA1-Low, the low-frequency component of the Square Kilometre Array (SKA), will undertake critical scientific missions such as probing the Epoch of Reionization (EoR). While frequency averaging can effectively reduce visibility data volume and improve sensitivity, it also introduces “bandwidth smearing”. The specific impact of this bandwidth smearing on SKA1-Low imaging currently lacks comprehensive quantitative analysis. In this study, we employ simulation methods to systematically investigate the effects of frequency averaging. By simulating the full SKA1-Low array, applying frequency averaging, and performing CLEAN deconvolution, we systematically compare restored images generated from multi-channel averaging against those from single-channel data, analyzing the resulting residual maps. Furthermore, we thoroughly examine the impact of frequency averaging on the intensity of observed sources, obtaining quantitative results that detail how peak intensity varies with the number of averaged channels under different imaging weightings. This research provides a valuable reference for selecting the optimal number of channels for frequency averaging during actual SKA1-Low observations, offering significant practical utility for future SKA1-Low scientific operations.