Volume 595, November 2016
|Number of page(s)||24|
|Published online||08 November 2016|
A detector interferometric calibration experiment for high precision astrometry
1 Institut de Planétologie et d’Astrophysique de Grenoble, 414 rue de la Piscine, Domaine Universitaire, 38400 St.-Martin-d’Hères, France
2 Commissariat à l’Énergie Atomique et aux Énergies Alternatives, Saclay, Centre d’études nucléaires de Saclay, Paris, France
3 Institut d’Astrophysique Spatiale, Centre universitaire d’Orsay, Paris, France
4 Centre National d’Études Spatiales, 2 place Maurice Quentin, Paris, France
5 Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
Received: 15 April 2015
Accepted: 17 August 2016
Context. Exoplanet science has made staggering progress in the last two decades, due to the relentless exploration of new detection methods and refinement of existing ones. Yet astrometry offers a unique and untapped potential of discovery of habitable-zone low-mass planets around all the solar-like stars of the solar neighborhood. To fulfill this goal, astrometry must be paired with high precision calibration of the detector.
Aims. We present a way to calibrate a detector for high accuracy astrometry. An experimental testbed combining an astrometric simulator and an interferometric calibration system is used to validate both the hardware needed for the calibration and the signal processing methods. The objective is an accuracy of 5 × 10-6 pixel on the location of a Nyquist sampled polychromatic point spread function.
Methods. The interferometric calibration system produced modulated Young fringes on the detector. The Young fringes were parametrized as products of time and space dependent functions, based on various pixel parameters. The minimization of function parameters was done iteratively, until convergence was obtained, revealing the pixel information needed for the calibration of astrometric measurements.
Results. The calibration system yielded the pixel positions to an accuracy estimated at 4 × 10-4 pixel. After including the pixel position information, an astrometric accuracy of 6 × 10-5 pixel was obtained, for a PSF motion over more than five pixels. In the static mode (small jitter motion of less than 1 × 10-3 pixel), a photon noise limited precision of 3 × 10-5 pixel was reached.
Key words: astrometry / space vehicles: instruments / instrumentation: high angular resolution / methods: data analysis / techniques: interferometric
© 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.