Pendular seismometer for correcting telescope vibrations |
| |
Authors: | A. Tokovinin &dagger |
| |
Affiliation: | CRAL-Observatoire de Lyon, 9 avenue Charles André, 69561 Saint Genis Laval cedex, France |
| |
Abstract: | Vibrations of telescopes can be successfully corrected in real time using a seismometer as an inertial reference. A prototype pendular seismometer is described that is suitable for angular vibration measurements at frequencies from a few tenths to several tens of Hz. The average pendulum position is maintained by a slow servo system that also damps its resonance. The prototype instrument has an rms noise of 3 milliarcsec in the 0–25-Hz band. It was tested on a 1-m telescope, and a good agreement of the seismometer signal with the direct optical measurements of the optical axis fluctuations of the telescope was found. A frequency response of the seismometer is studied, an expression for the rms amplitude of residual (uncompensated) vibrations is given. In space applications it is suggested that a pendular mirror in front of the telescope is used as an inertial reference for vibration correction. |
| |
Keywords: | instrumentation: miscellaneous telescopes |
|
|