# PEPITO: atmospheric Profiling from short-Exposure focalPlane Images in seeing-limiTed mOde

## TL;DR

PEPITO is a novel method for atmospheric turbulence profiling using short-exposure images, enabling high-resolution, sensitive, and rapid characterization crucial for adaptive optics and site assessment.

## Contribution

It introduces a new model-fitting approach leveraging anisokinetism in short-exposure images for accurate atmospheric turbulence profiling.

## Key findings

- Achieves better than 1% accuracy in turbulence profile estimation in simulations.
- Effective with a 0.5m telescope and V=11 stars within a 10 arcmin field.
- Provides high vertical resolution (1-400m) configurable by camera pixel scale.

## Abstract

Atmospheric profiling is a requirement for controlling wide-field Adaptive Optics (AO) instruments, analyzing the AO performance with respect to the observing conditions and predicting the Point Spread Function (PSF) spatial variations. We present PEPITO, a new concept for profiling atmospheric turbulence from {\em post~facto} tip-tilt (TT) corrected short-exposure images. PEPITO utilizes the anisokinetism effect in the images between several stars separated from a reference star, and then produces the profile estimation using a model-fitting methodology, by fitting to the long exposure TT-corrected PSF. PEPITO has a high sensitivity to both $C_n^2(h)$ and $L_0(h)$ by relying on the full telescope aperture and a large field of view. It then obtains a high vertical resolution (1\,m-400\,m) configurable by the camera pixel scale, taking advantage of fast statistical convergence (of order of tens of seconds). With only a short exposure-capable large format detector and a numerical complexity independent of the telescope diameter, PEPITO perfectly suits accurate profiling for night optical turbulence site characterization or adaptive optics instruments operations. We demonstrate, in simulation, that the $C_n^2(h)$ and $L_0(h)$ can be estimated to better than 1\% accuracy, from fitted PSFs of magnitude V=11 on a D=0.5\,m telescope with a 10 arcmin field of view.