Atmospheric turbulence profiling with multi-aperture scintillation of a Shack-Hartmann sensor

TL;DR

This paper introduces a new method to reconstruct atmospheric turbulence profiles using scintillation data from a Shack-Hartmann sensor, enhancing the vertical resolution for adaptive optics systems.

Contribution

The novel approach extends the MASS technique by utilizing scintillation patterns from Shack-Hartmann subapertures, enabling reconstruction of more than 10 turbulence layers.

Findings

Successfully reconstructed turbulence profiles with over 10 layers.

Demonstrated the method's effectiveness with a 50 cm telescope at Tohoku University.

General characteristics of atmospheric turbulence profile were accurately reproduced.

Abstract

Adaptive optics (AO) systems using tomographic estimation of three-dimensional structure of atmospheric turbulence requires vertical atmospheric turbulence profile, which describes turbulence strength as a function of altitude as a prior information. We propose a novel method to reconstruct the profile by applying Multi Aperture Scintillation Sensor (MASS) method to scintillation data obtained by a Shack-Hartmann wavefront sensor (SH-WFS). Compared to the traditional MASS, which uses atmospheric scintillation within 4 concentric annular apertures, the new method utilizes scintillation in several hundreds of spatial patterns, which are created by combinations of SH-WFS subapertures. Accuracy of the turbulence profile reconstruction is evaluated with Bayesian inference, and it is confirmed that turbulence profile with more than 10 layers can be reconstructed thanks to the large number of constraints. We demonstrate the new method with a SH-WFS attached to the 50 cm telescope at Tohoku university and confirm that general characteristics of atmospheric turbulence profile is reproduced.