SKA Aperture Array Verification System: Electromagnetic modeling and beam pattern measurements using a micro UAV

TL;DR

This study combines electromagnetic modeling and UAV-based beam pattern measurements to validate a sparse array prototype for the SKA telescope, aiding calibration and design optimization.

Contribution

It introduces a UAV-based measurement approach for array pattern validation and calibration in the development of SKA telescope components.

Findings

Good agreement between measurements and simulations.

Localized effects of uncalibrated cable lengths on side-lobes.

UAV system provides stable RF signals for calibration.

Abstract

In this paper we present the electromagnetic modeling and beam pattern measurements of a 16-elements ultra wideband sparse random test array for the low frequency instrument of the Square Kilometer Array telescope. We discuss the importance of a small array test platform for the development of technologies and techniques towards the final telescope, highlighting the most relevant aspects of its design. We also describe the electromagnetic simulations and modeling work as well as the embedded-element and array pattern measurements using an Unmanned Aerial Vehicle system. The latter are helpful both for the validation of the models and the design as well as for the future instrumental calibration of the telescope thanks to the stable, accurate and strong radio frequency signal transmitted by the UAV. At this stage of the design, these measurements have shown a general agreement between experimental results and numerical data and have revealed the localized effect of un-calibrated cable lengths in the inner side-lobes of the array pattern.