Performance Evaluation of Baseline-dependent Averaging Based on Full-scale SKA1-LOW Simulation

The Square Kilometre Array (SKA) is the largest radio interferometer under construction in the world. Its immense amount of visibility data poses a considerable challenge to the subsequent processing by the science data processor (SDP). Baseline dependent averaging (BDA), which reduces the amount of visibility data based on the baseline distribution of the radio interferometer, has become a focus of SKA SDP development. This paper developed and implemented a full-featured BDA module based on Radio Astronomy Simulation, Calibration and Imaging Library (RASCIL). Simulated observations were then performed with RASCIL based on a full-scale SKA1-LOW configuration. The performance of the BDA was systematically investigated and evaluated based on the simulated data. The experimental results confirmed that the amount of visibility data is reduced by about 50% to 85% for different time intervals ( Δtmax). In addition, different Δtmax have a significant effect on the imaging quality. The smaller Δtmax is, the smaller the degradation of imaging quality.