Alignment and preliminary outcomes of an ELT-size instrument to a very large telescope: LINC-NIRVANA at LBT

TL;DR

This paper discusses the alignment process and initial results of LINC-NIRVANA, a large, high-resolution infrared instrument on the LBT, aiming to achieve ELT-like imaging capabilities with advanced adaptive optics.

Contribution

It introduces an alignment strategy for a large, ELT-sized instrument on the LBT and presents early commissioning results demonstrating its effectiveness.

Findings

Successful alignment of LINC-NIRVANA to the LBT telescope.

Initial commissioning results show promising system performance.

The alignment procedure is comparable to planned ELT instrumentation strategies.

Abstract

LINC-NIRVANA (LN) is a high resolution, near infrared imager that uses a multiple field-of-view, layer-oriented, multi-conjugate AO system, consisting of four multi-pyramid wavefront sensors (two for each arm of the Large Binocular Telescope, each conjugated to a different altitude). The system employs up to 40 star probes, looking at up to 20 natural guide stars simultaneously. Its final goal is to perform Fizeau interferometric imaging, thereby achieving ELT-like spatial resolution (22.8 m baseline resolution). For this reason, LN is also equipped with a fringe tracker, a beam combiner and a NIR science camera, for a total of more than 250 optical components and an overall size of approximately 6x4x4.5 meters. This paper describes the tradeoffs evaluated in order to achieve the alignment of the system to the telescope. We note that LN is comparable in size to planned ELT instrumentation. The impact of such alignment strategies will be compared and the selected procedure, where the LBT telescope is, in fact, aligned to the instrument, will be described. Furthermore, results coming from early night-time commissioning of the system will be presented.