Optical turbulence forecast: ready for an operational application

TL;DR

This study evaluates the Astro-Meso-Nh model's ability to forecast optical turbulence parameters at ESO sites, demonstrating its high accuracy and readiness for operational use in supporting top-tier telescopes and ELTs.

Contribution

The paper presents a comprehensive validation of the Astro-Meso-Nh model's performance in predicting optical turbulence, highlighting its suitability for operational deployment at major observatory sites.

Findings

The model accurately predicts key optical turbulence parameters.

Performance metrics show high success rates in detection within specific ranges.

The model is ready for automatic operational implementation at VLT and E-ELT sites.

Abstract

One of the main goals of the feasibility study MOSE (MOdellig ESO Sites) is to evaluate the performances of a method conceived to forecast the optical turbulence above the ESO sites of the Very Large Telescope and the European-Extremely Large Telescope in Chile. The method implied the use of a dedicated code conceived for the optical turbulence (OT) called Astro-Meso-Nh. In this paper we present results we obtained at conclusion of this project concerning the performances of this method in forecasting the most relevant parameters related to the optical turbulence (CN2, seeing , isoplanatic angle theta_0 and wavefront coherence time tau_0). Numerical predictions related to a very rich statistical sample of nights uniformly distributed along a solar year and belonging to different years have been compared to observations and different statistical operators have been analyzed such as classical bias, RMSE and and more sophisticated statistical operators derived by the contingency tables that are able to quantify the score of success of a predictive method such as the percentage of correct detection (PC) and the probability to detect a parameter within a specific range of values (POD). The main conclusions of the study tell us that the Astro-Meso-Nh model provides performances that are already very good to definitely guarantee a not negligible positive impact on the Service Mode of top-class telescopes and ELTs. A demonstrator for an automatic and operational version of the Astro-Meso-Nh model will be soon implemented on the sites of VLT and E-ELT.