Metrology concept design of the GAIA basic angle monitoring system

A.A. Veggel, van, H.J.P. Vink, P.C.J.N. Rosielle, H. Nijmeijer, A.A. Wielders

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

4 Citations (Scopus)
2 Downloads (Pure)


The GAIA satellite, scheduled for launch in 2010, will make a highly accurate map of our Galaxy. It will measure the position of stars with an accuracy of 50 prad using two telescopes, which are positioned under a 'basic' angle between the the lines-of-sight of the telescopes of 106°. With a Basic Angle Monitoring system, variations of this angle will be measured with 5 prad accuracy, to correct for these variations on the measured position of stars. A conceptual design of the Basic Angle Monitoring system is presented. Two pairs of parallel laser bundles are sent to the telescopes, which create two interference patterns. If the basic angle varies, the interference patterns will shift. The optical design is such that the rotation of one pair of beams with respect to the other pair, does not affect the measured basic angle. The position stability requirement of the mirrors is a maximum shift of 1 pm in 6 hours. For material stability and good thermal and mechanical properties, Silicon Carbide has been chosen. The structural design is such that the design is as much monolithic as possible. The alignment is performed along the horizontal plane with external and removable alignment mechanisms. The components are locked by adhesives.
Original languageEnglish
Title of host publicationAstronomical structures and mechanisms technology, 21-22 June 2004, Glasgow, Scotland, UK. Vol. 1
EditorsJ. Antebi, D. Lemke
Place of PublicationBellingham
ISBN (Print)0-8194-5427-3
Publication statusPublished - 2004
Eventconference; Astronomical structures and mechanisms technology -
Duration: 1 Jan 2004 → …

Publication series

NameProceedings of SPIE
ISSN (Print)0277-786X


Conferenceconference; Astronomical structures and mechanisms technology
Period1/01/04 → …
OtherAstronomical structures and mechanisms technology

Fingerprint Dive into the research topics of 'Metrology concept design of the GAIA basic angle monitoring system'. Together they form a unique fingerprint.

Cite this