Towards a pure PSF-R service for MICADO@E-ELT

MICADO [1] is the Multi-AO Imaging Camera for Deep Observations and it is one of the first light instruments of
the ESO Extremely Large Telescope [2, 3] (E-ELT), providing imaging and long-slit spectroscopy at near-infrared
wavelengths. It will exploit single conjugate adaptive optics [4] (SCAO) with natural guide star in stand-alone mode
since the first light of E-ELT. A multi-conjugate adaptive optics (MCAO) will be also accessible for this instrument
with the implementation of the MAORY module [5].
In general, reconstructing the PSF of AO instrumentation is challenging, since it is much more complex than in the
traditional seeing-limited case or for space based telescopes. This is even more true for E-ELT. However, a detailed
knowledge of the PSF is required to fulfill most of the scientific goals [6]. For this reason, the PSF reconstruction
(PSF-R) is a planned deliverable of the MICADO consortium. Our group in particular focuses on the work package in
charge of the PSF-R development [7]. The goal is to provide the final user with reconstructed PSFs through an archive
querying system restoring the full telemetry data synchronous to each science frame that MICADO will generate. The
PSF-R service will support the state-of-the-art scientific analysis of the MICADO imaging and spectroscopic data.
The PSF-R method we are currently implementing is described in Wagner et. al (2018) [8]. It consists of an up-
date of Veran et al. (1997) [9]: in practice, a telemetry-only PSF-R approach is being pursued. This means that the
reconstructed PSFs are obtained independently from focal plane science images. In particular, our PSF-R algorithm
makes use of (i) WFS images and telemetry generated by the AO system, (ii) information by other systems monitoring
the atmosphere and (iii) telemetry from the E-ELT and MICADO instrument. All these technical data need to be syn-
chronous to the science observations for which the reconstructed PSFs have to be obtained. The telemetry-only PSF-R
approach allows the flexibility to reconstruct the PSF even in the absence of useful point sources in the science images
- a common occurrence in, but not limited to, extragalactic targets [6, 7].
In this presentation it is discussed the status of the MICADO PSF-R deliverable, demonstrating its readiness level
by presenting the results of a recent application of the method to real SCAO data taken at Large Binocular Telescope
(LBT) with SOUL/LUCI [10]. Archival data, accompanied by the related full telemetry, have been used to test the
performances of our PSF-R algorithm. The reconstructed PSFs reproduce the observed ones with an accuracy better
than 2% in Strehl ratio and 5% in full width at half maximum. It is also presented the results of the scientific evaluation
of these reconstructed PSFs for a simulated, typical extragalactic case.

References
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