Issue |
A&A
Volume 594, October 2016
|
|
---|---|---|
Article Number | A38 | |
Number of page(s) | 12 | |
Section | Astronomical instrumentation | |
DOI | https://doi.org/10.1051/0004-6361/201628299 | |
Published online | 07 October 2016 |
Direct illumination calibration of telescopes at the quantum precision limit
LPNHE, CNRS-IN2P3 and Universités Paris 6 and 7, 4 place Jussieu, 75252 Paris Cedex 05, France
e-mail: barrelet@lpnhe.in2p3.fr
Received: 12 February 2016
Accepted: 3 July 2016
The electronic response of a telescope under direct illumination by a point-like light source is based on photon counting. With the data obtained using the SNDICE light source and the Megacam camera on the CFHT telescope, we show that the ultimate precision is only limited by the photon statistical fluctuation, which is below 1 ppm. A key feature of the analysis is the incorporation of diffuse light that interfers with specularly reflected light in the transmission model to explain the observed diffraction patterns. The effect of diffuse light, usually hidden conveniently in the Strehl ratio for an object at infinity, is characterized with a precision of 10 ppm. In particular, the spatial frequency representation provides some strong physical constraints and a practical monitoring of the roughness of various optical surfaces.
Key words: instrumentation: detectors / techniques: photometric / methods: statistical / telescopes / methods: numerical / methods: miscellaneous
© ESO, 2016
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.