Sensor fusion on MagAO-X: real time vibration control using accelerometers

Abstract

Mechanical vibrations are a significant source of residual wavefront error (WFE) in adaptive optics (AO) systems, limiting the performance of high-contrast imaging instruments. We present the design and on-sky deployment of a low-cost, modular accelerometer telemetry system for the MagAO-X extreme AO instrument on the 6.5m Clay Magellan Telescope, consisting of piezoelectric accelerometers and a Raspberry Pi-based acquisition system that streams synchronized data to the real-time control computer with microsecond-level timing stability. The system is used to identify dominant telescope vibration sources and quantify their coupling to AO telemetry, revealing that several narrow-band modes originate from subsystems including the primary mirror glycol pump, secondary mirror actuation system, and telescope autofocus system. Coherence analysis between accelerometer and wavefront sensor (WFS) measurements indicates that approximately one-third of the residual tip and tilt WFE is correlated with structural vibrations. The synchronized telemetry is applied to predictive control algo rithms, where the empirical orthogonal functions predictor achieves offline variance reductions of 23% in tip and 37% in tilt. Simulations indicate that combining accelerometer feedforward control with WFS predictive control can provide order-of-magnitude suppression at vibration dominated frequencies. These results demonstrate that low-cost accelerometer telemetry provides a practical approach for vibration identification and predictive control in current and future AO systems.

Authors 19

1. Parker T. Johnson

   University of Arizona

   Affiliation as printed

   Steward Observatory, Univ. of Arizona (United States)

2. Jared R. Males

   University of Arizona

   Affiliation as printed

   Steward Observatory, Univ. of Arizona (United States)

3. Povilas Palunas

   Las Campanas Observatory

   Affiliation as printed

   Las Campanas Observatory (Chile)

4. Olivier Guyon

   University of Arizona · National Astronomical Observatory of Japan

   Affiliation as printed

   Steward Observatory, The Univ. of Arizona (United States)

   Subaru Telescope, National Astronomical Observatory of Japan (United States)

   Wyant College of Optical Sciences, The Univ. of Arizona (United States)

5. Sebastiaan Haffert Aachen Leiden Observatory

   Leiden University · University of Arizona · Leiden Observatory

   Affiliation as printed

   Leiden Observatory, Leiden Univ. (Netherlands)

   Steward Observatory, The Univ. of Arizona (United States)

6. Joseph D. Long

   Flatiron Institute

   Affiliation as printed

   Flatiron Institute (United States)

7. Vincent Déo

   National Astronomical Observatory of Japan

   Affiliation as printed

   Optical Sharpeners SAS (France)

   Subaru Telescope, National Astronomical Observatory of Japan (United States)

8. Julien Lozi

   National Astronomical Observatory of Japan

   Affiliation as printed

   Subaru Telescope, National Astronomical Observatory of Japan (United States)

9. Laird M. Close

   University of Arizona

   Affiliation as printed

   Steward Observatory, The Univ. of Arizona (United States)

10. Maggie Kautz

    University of Arizona

    Affiliation as printed

    Steward Observatory, The Univ. of Arizona (United States)

11. Jay Kueny

    U.S. National Science Foundation · University of Arizona

    Affiliation as printed

    National Science Foundation (United States)

    Steward Observatory, The Univ. of Arizona (United States)

    Wyant College of Optical Sciences, The Univ. of Arizona (United States)

12. Jialin Li

    U.S. National Science Foundation · University of Arizona

    Affiliation as printed

    National Science Foundation (United States)

    Steward Observatory, The Univ. of Arizona (United States)

13. Joshua Liberman

    University of Arizona

    Affiliation as printed

    Steward Observatory, The Univ. of Arizona (United States)

    Wyant College of Optical Sciences, The Univ. of Arizona (United States)

14. Miles Lucas

    University of Arizona · National Astronomical Observatory of Japan

    Affiliation as printed

    Steward Observatory, The Univ. of Arizona (United States)

    Subaru Telescope, National Astronomical Observatory of Japan (United States)

15. Matthijs Mars Aachen Leiden Observatory

    Leiden University · Leiden Observatory

    Affiliation as printed

    Leiden Observatory, Leiden Univ. (Netherlands)

16. Eden McEwen

    U.S. National Science Foundation · University of Arizona

    Affiliation as printed

    National Science Foundation (United States)

    Steward Observatory, The Univ. of Arizona (United States)

    Wyant College of Optical Sciences, The Univ. of Arizona (United States)

17. Tiffany Nguyen

    University of Arizona

    Affiliation as printed

    Wyant College of Optical Sciences, The Univ. of Arizona (United States)

18. Elena Tonucci Aachen Leiden Observatory

    Leiden University · Leiden Observatory

    Affiliation as printed

    Leiden Observatory, Leiden Univ. (Netherlands)

19. Katie Twitchell

    University of Arizona

    Affiliation as printed

    Steward Observatory, The Univ. of Arizona (United States)

    Wyant College of Optical Sciences, The Univ. of Arizona (United States)