Feed-forward vibration compensation for small telescopes

Abstract

This publication investigates the applicability of feed-forward vibration compensation for small telescope systems in one axis, based on commercial-off-the-shelf accelerometers and a fast-steering mirror (FSM). The vibrations are measured with multiple accelerometers and their influence onto the optical path is reconstructed using a highpass filtered double integrator. Consequently, the reconstructed deviations are compensated in a feed-forward control manner by the FSM. A quad-photo-diode and an artificial star are used for verification of the performance of the system. Exemplary disturbance spectra are acquired on a roof-top using a small telescope system. They are applied to the developed system in a laboratory environment, successfully demonstrating the applicability of the proposed compensation concept by reducing the RMS tip-tilt error of the azimuth axis by a factor of 2.2 in the relevant frequency range.