DM/WFS mis-registration tracking: Implementation and on-sky validation of SPRINT at LBT
arXiv:2607.27941
The paper describes the implementation of the SPRINT method on the Large Binocular Telescope to track and correct mis‑registrations between the deformable mirror and wavefront sensor, demonstrating its performance with daytime and on‑sky tests.
Abstract
The advent of telescopes with an integrated deformable mirror (DM) presents new challenges for adaptive optics (AO) systems. The alignment between the DM and wavefront sensor (WFS) is expected to regularly evolve during operations due to their large separation. Without tracking and correction, these mis-registrations between the DM and WFS lead to loop instability, preventing diffraction limited performance from being realised. SPRINT\cite{heritier2021} provides an approach to track these mis-registrations during observations. Rotation, shift, and magnification mis-registrations can all be recovered. The Large Binocular Telescope (LBT) currently lacks an operational solution for tracking these mis-registrations, while SPRINT has been selected as the baseline approach for several instruments on the forthcoming Extremely Large Telescope (ELT). We report on the implementation of SPRINT into the LBT real time computer and present experimental results from both daytime and on-sky testing to validate the method.
7 pages, 7 figures, SPIE Astronomical Telescopes + Instrumentation 2026