Rolling shutter detector for adaptive optics wavefront sensing

F. Gago; Enrico Marchetti; Marcos Suarez-Valles

doi:10.1117/12.3018997

27 August 2024 Rolling shutter detector for adaptive optics wavefront sensing

F. Gago , Enrico Marchetti, Marcos Suarez-Valles

Proceedings Volume 13097, Adaptive Optics Systems IX; 130977T (2024) https://doi.org/10.1117/12.3018997
Event: SPIE Astronomical Telescopes + Instrumentation, 2024, Yokohama, Japan

Conference Poster

Abstract

The use of rolling shutter (RS) detectors for wavefront sensing in Adaptive Optics (AO) allows for a reduced control loop latency. However, time-varying low-order atmospheric modes are partially leaked into high-order (HO) ones. While this is not a problem with Natural Guide Stars, for Laser Guide Stars (LGS) the uplink jitter component (discarded in the AO loop together with the atmospheric tip-tilt) will leak into the HO controller and generate unwanted extra correction (in the order of hundreds of nanometers in the case of Extremely Large Telescopes), severely impairing the AO correction performance. In this paper we analyze this effect and present an algorithm to effectively minimize the impact of the LGS jitter leak into higher orders while preserving the advantage of reduced latency. Additionally, we briefly discuss the impact of its implementation in the Real-Time Computer (RTC). We also describe the adopted discrete-time simulation framework at AO loop rate which we developed to capture the particularities of RS detectors, but which is also applicable to global shutter detectors. This framework exactly represents in z-space all sub-frame delays, actuator dynamics and any arbitrary detector readout scheme while improving the simulation accuracy when compared to continuous models based on Laplace-transform approximations. It also allows for considerably faster simulations than pure continuous or mixed discrete-continuous models and simplifies the control loop analysis (stability, robustness, etc.). We finally address the implementation of pseudo open-loop control (POLC) with RS detectors, as well as the impact of vibrations.

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

F. Gago , Enrico Marchetti, and Marcos Suarez-Valles "Rolling shutter detector for adaptive optics wavefront sensing", Proc. SPIE 13097, Adaptive Optics Systems IX, 130977T (27 August 2024); https://doi.org/10.1117/12.3018997

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