Numerical control matrix rotation for the LINC-NIRVANA Multi-Conjugate Adaptive Optics system

TL;DR

This paper addresses real-time numerical control matrix adjustments for pupil rotation in the LINC-NIRVANA adaptive optics system, aiming to maintain high correction accuracy amid field rotation effects.

Contribution

It introduces a method for real-time computation of control matrix adjustments to counter pupil rotation effects in multi-conjugate adaptive optics systems.

Findings

Quantifies wave-front errors caused by pupil rotation.

Analyzes temporal and computational requirements for real-time adjustments.

Abstract

LINC-NIRVANA will realize the interferometric imaging focal station of the Large Binocular Telescope. A double Layer Oriented multi-conjugate adaptive optics system assists the two arms of the interferometer, supplying high order wave-front correction. In order to counterbalance the field rotation, mechanical derotation for the two ground wave-front sensors, and optical derotators for the mid-high layers sensors fix the positions of the focal planes with respect to the pyramids aboard the wave-front sensors. The derotation introduces pupil images rotation on the wavefront sensors: the projection of the deformable mirrors on the sensor consequently change. The proper adjustment of the control matrix will be applied in real-time through numerical computation of the new matrix. In this paper we investigate the temporal and computational aspects related to the pupils rotation, explicitly computing the wave-front errors that may be generated.