Compressed sensing for wide-field radio interferometric imaging

TL;DR

This paper extends compressed sensing techniques to wide-field radio interferometric imaging by reconstructing images directly on the sphere, improving image quality and avoiding distortions inherent in planar projections.

Contribution

It introduces a spherical compressed sensing approach for WFOV interferometric imaging, enhancing reconstruction quality by leveraging the sphere's natural geometry.

Findings

Spherical reconstruction outperforms planar methods in image quality.

The spread spectrum phenomenon is more effective in WFOV scenarios.

Direct spherical recovery promotes sparsity and improves fidelity.

Abstract

For the next generation of radio interferometric telescopes it is of paramount importance to incorporate wide field-of-view (WFOV) considerations in interferometric imaging, otherwise the fidelity of reconstructed images will suffer greatly. We extend compressed sensing techniques for interferometric imaging to a WFOV and recover images in the spherical coordinate space in which they naturally live, eliminating any distorting projection. The effectiveness of the spread spectrum phenomenon, highlighted recently by one of the authors, is enhanced when going to a WFOV, while sparsity is promoted by recovering images directly on the sphere. Both of these properties act to improve the quality of reconstructed interferometric images. We quantify the performance of compressed sensing reconstruction techniques through simulations, highlighting the superior reconstruction quality achieved by recovering interferometric images directly on the sphere rather than the plane.