Towards an automatic wind speed and direction profiler for Wide Field AO systems

TL;DR

This paper evaluates the reliability of wind speed and direction measurements in Wide Field Adaptive Optics systems, comparing SLODAR-based data with atmospheric model predictions, and proposes an automatic monitoring method using the Meso-Nh model.

Contribution

It introduces a simple automatic method for monitoring wind profiles in WFAO systems using the Meso-Nh model, validated against GeMS measurements and atmospheric models.

Findings

Excellent agreement between GeMS and Meso-Nh model data.

Validation of the SLODAR technique for wind profiling.

Proposed automatic wind monitoring method applicable to future facilities.

Abstract

Wide Field Adaptive Optics (WFAO) systems are among the most sophisticated AO systems available today on large telescopes. The knowledge of the vertical spatio-temporal distribution of the wind speed (WS) and direction (WD) are fundamental to optimize the performance of such systems. Previous studies already proved that the Gemini Multi-Conjugated AO system (GeMS) is able to retrieve measurements of the WS and WD stratification using the SLODAR technique and to store measurements in the telemetry data. In order to assess the reliability of these estimates and of the SLODAR technique applied to such a kind of complex AO systems, in this study we compared WS and WD retrieved from GeMS with those obtained with the atmospherical model Meso-Nh on a rich statistical sample of nights. It has been previously proved that, the latter technique, provided an excellent agreement with a large sample of radiosoundings both, in statistical terms and on individual flights. It can be considered, therefore, as an independent reference. The excellent agreement between GeMS measurements and the model that we find in this study, proves the robustness of the SLODAR approach. To by-pass the complex procedures necessary to achieve automatic measurements of the wind with GeMS, we propose a simple automatic method to monitor nightly WS and WD using the Meso-Nh model estimates. Such a method can be applied to whatever present or new generation facilities supported by WFAO systems. The interest of this study is, therefore, well beyond the optimization of GeMS performance.