Accurate measurement of Cn2 profile with Shack-Hartmann data

TL;DR

This paper introduces CO-SLIDAR, a new method combining slope and scintillation data from Shack-Hartmann sensors to accurately measure the Cn2 turbulence profile across different altitudes, improving adaptive optics systems.

Contribution

The paper presents a novel CO-SLIDAR technique that enhances Cn2 profile measurement accuracy by integrating slope and scintillation correlations from Shack-Hartmann data.

Findings

CO-SLIDAR provides accurate Cn2 profiles for low and high altitudes.

The method effectively accounts for detection noise and bias.

Results outperform methods using only slopes or scintillation correlations.

Abstract

The precise reconstruction of the turbulent volume is a key point in the development of new-generation Adaptive Optics systems. We propose a new Cn2 profilometry method named CO-SLIDAR (COupled Slope and scIntillation Detection And Ranging), that uses correlations of slopes and scintillation indexes recorded on a Shack-Hartmann from two separated stars. CO-SLIDAR leads to an accurate Cn2 retrieval for both low and high altitude layers. Here, we present an end-to-end simulation of the Cn2 profile measurement. Two Shack-Hartmann geometries are considered. The detection noises are taken into account and a method to subtract the bias is proposed. Results are compared to Cn2 profiles obtained from correlations of slopes only or correlations of scintillation indexes only.