Fresnel diffraction and polychromatic effects on angle-of-arrival fluctuations
- Others:
- Laboratoire Hippolyte Fizeau (FIZEAU) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS) ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
- Centre de Recherche en Astronomie Astrophysique et Géophysique (CRAAG)
- Service d'aéronomie (SA) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Description
Seeing monitoring in astronomy is widely based on the statistical analysis of angle-of-arrival (AA) fluctuations, which are usually modelled in the framework of the near-field approximation where diffraction through turbulence is ignored. They are consequently believed to be completely independent of wavelength. We discuss in this paper the influence of Fresnel diffraction from distant turbulence layers on multi-wavelength (polychromatic) AA fluctuations. For this purpose we propose a model for polychromatic AA fluctuations in weak turbulence conditions and derive an analytical model for their variance in the case where scintillation is ignored. We also present a numerical simulation that includes scintillation and justifies that this latter may be neglected in the analytical model.
Abstract
International audience
Additional details
- URL
- https://hal.archives-ouvertes.fr/hal-00416981
- URN
- urn:oai:HAL:hal-00416981v1
- Origin repository
- UNICA