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Lennart Lindegren. Profile picture.

Lennart Lindegren

Professor

Lennart Lindegren. Profile picture.

Gaia on-board metrology: basic angle and best focus

Author

  • A. Mora
  • M. Biermann
  • A. G. A. Brown
  • D. Busonero
  • L. Carminati
  • J. M. Carrasco
  • F. Chassat
  • M. Erdmann
  • W. L. M. Gielesen
  • C. Jordi
  • D. Katz
  • R. Kohley
  • Lennart Lindegren
  • W. Loeffler
  • O. Marchal
  • P. Panuzzo
  • G. Seabroke
  • J. Sahlmann
  • E. Serpell
  • I. Serraller
  • F. van Leeuwen
  • W. van Reeven
  • T. C. van den Dool
  • L. L. A. Vosteen
Show all

Summary, in English

The Gala payload ensures maximum passive stability using a single material, SiC, for most of its elements. Dedicated metrology instruments are, however, required to carry out two functions: monitoring the basic angle and refocusing the telescope. Two interferometers fed by the same laser are used to measure the basic angle changes at the level of pas (prad, micropixel), which is the highest level ever achieved in space. Two ShackHartmann wavefront sensors, combined with an ad-hoc analysis of the scientific data are used to define and reach the overall best-focus. In this contribution, the systems, data analysis, procedures and performance achieved during commissioning are presented

Department/s

  • Lund Observatory - Undergoing reorganization

Publishing year

2014

Language

English

Pages

91430-91430

Publication/Series

Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave

Volume

9143

Document type

Conference paper

Publisher

SPIE

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • Astrometry
  • Gaia
  • metrology
  • interferometry
  • basic angle monitor
  • wavefront sensor
  • Shack-Hartmann
  • wavefront reconstruction
  • centroid
  • Cramer-Rao
  • spectral resolution

Conference name

Conference on Space Telescopes and Instrumentation - Optical, Infrared, and Millimeter Wave

Conference date

2014-06-22 - 2014-06-27

Conference place

Montreal, Canada

Status

Published

ISBN/ISSN/Other

  • ISSN: 1996-756X
  • ISSN: 0277-786X