Sensitivity improvements for Shack-Hartmann wavefront sensors using total variation minimisation

TL;DR

This paper demonstrates that applying total variation minimisation to Shack-Hartmann wavefront sensor images enhances sensitivity, enabling up to one magnitude improvement in adaptive optics performance through simulations and on-sky tests.

Contribution

It introduces a novel application of total variation minimisation for noise reduction in wavefront sensing, showing real-time feasibility and significant sensitivity gains.

Findings

Sensitivity improvements of up to one magnitude demonstrated

Effective noise reduction through total variation minimisation

Real-time implementation validated with on-sky measurements

Abstract

We investigate the improvements in Shack-Hartmann wavefront sensor image processing that can be realised using total variation minimisation techniques to remove noise from these images. We perform Monte-Carlo simulation to demonstrate that at certain signal-to-noise levels, sensitivity improvements of up to one astronomical magnitude can be realised. We also present on-sky measurements taken with the CANARY adaptive optics system that demonstrate an improvement in performance when this technique is employed, and show that this algorithm can be implemented in a real-time control system. We conclude that total variation minimisation can lead to improvements in sensitivity of up to one astronomical magnitude when used with adaptive optics systems.