Aperture Array Configurations for SKA1 Core

TL;DR

This paper explores innovative aperture array configurations for SKA1 Low Frequency, proposing shared elements and apodisation at the element level, and randomized station layouts to enhance sensitivity and sidelobe performance.

Contribution

It introduces a novel element sharing and apodisation scheme, and investigates randomized station configurations for improved array performance.

Findings

Shared element scheme improves filling factor and sensitivity.

Randomized station layout enhances sidelobe suppression.

Trade-offs include increased beamformer complexity.

Abstract

This memo considers some aspects of the configuration of the SKA1 Low Frequency Aperture Array, both at the element and station level. At the element level I propose a possible scenario for forming station beams where elements are shared between stations and apodisation is implemented, with the aim of improving filling factor, overall sensitivity and sidelobe performance; the disadvantages of such a scheme with regards to beam former requirements and shortest available baseline are also discussed. At the station level, a randomised configuration within a filled central region together with spiral arms is explored.