Application of Hartmann linear calibrations to ViLLaGEs

S. Mark Ammons; Donald T. Gavel; Daren R. Dillon; Marco Reinig; Bryant Grigsby; Katie M. Morzinski

doi:10.1117/12.789816

14 July 2008 Application of Hartmann linear calibrations to ViLLaGEs

S. Mark Ammons, Donald T. Gavel, Daren R. Dillon, Marco Reinig, Bryant Grigsby, Katie M. Morzinski

Proceedings Volume 7015, Adaptive Optics Systems; 701546 (2008) https://doi.org/10.1117/12.789816
Event: SPIE Astronomical Telescopes + Instrumentation, 2008, Marseille, France

Abstract

We attempt to linearize the output of the Shack-Hartmann wavefront sensor in the ViLLaGEs instrument. ViLLaGEs (Visible Light Laser Guidestar Experiments) is a MEMS-based Adaptive Optics system on the 1 - meter Nickel telescope at Lick Observatory meant to provide correction at visible wavelengths with a 9x9 subaperture Hartmann sensor. We estimate that the open-loop accuracy of ViLLaGEs is ~40 nm. We "calibrate" the Hartmann linearity by raster scanning a tip/tilt mirror downstream of an internal fiber and inverting the resulting signal, forming a lookup table of unbiased tilts. From this calibration, we conclude that nonlinearity is a minor effect in the open-loop operation of ViLLaGEs, on the order of ~15 nm. We show through simulations of Shack-Hartmann sensors that this error is likely due to an internal pupil mask not physically conjugate to the telescope pupil. We test the resulting lookup table on an internal "turbulator" in ViLLaGEs, or a rotating plate meant to simulate the wind-driven atmosphere, and find that the Strehls with and without the lookup table are indistinguishable.

Citation Download Citation

S. Mark Ammons, Donald T. Gavel, Daren R. Dillon, Marco Reinig, Bryant Grigsby, and Katie M. Morzinski "Application of Hartmann linear calibrations to ViLLaGEs", Proc. SPIE 7015, Adaptive Optics Systems, 701546 (14 July 2008); https://doi.org/10.1117/12.789816

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available