Point spread function reconstruction for SOUL+LUCI LBT data

TL;DR

This paper develops a PSF reconstruction software for adaptive optics data on the LBT, testing pyramid wave-front sensor data and achieving high accuracy in PSF modeling for scientific applications.

Contribution

It introduces the first implementation of pyramid wave-front sensor data in PSF reconstruction algorithms for AO observations.

Findings

Reconstructed PSFs differ less than 2% in Strehl ratio from observed PSFs.

Reconstructed PSFs differ less than 4.5% in FWHM from observed PSFs.

The method accurately recovers the encircled energy within 4% in the worst case.

Abstract

This paper presents the status of an ongoing project aimed at developing a PSF reconstruction software for adaptive optics (AO) observations. In particular, we test for the first time the implementation of pyramid wave-front sensor data on our algorithms. As a first step in assessing its reliability, we applied the software to bright, on-axis, point-like sources using two independent sets of observations, acquired with the single-conjugated AO upgrade for the Large Binocular Telescope. Using only telemetry data, we reconstructed the PSF by carefully calibrating the instrument response. The accuracy of the results has been first evaluated using the classical metric: specifically, the reconstructed PSFs differ from the observed ones by less than 2% in Strehl ratio and 4.5% in full-width at half maximum. Moreover, the recovered encircled energy associated with the PSF core is accurate at 4% level in the worst case. The accuracy of the reconstructed PSFs has then been evaluated by considering an idealized scientific test-case consisting in the measurements of the morphological parameters of a compact galaxy. In the future, our project will include the analysis of anisoplanatism, low SNR regimes, and the application to multi-conjugated AO observations.