The Multiple Field of View Layer Oriented wavefront sensing system of LINC-NIRVANA: two arcminutes of corrected field using solely Natural Guide Stars

Farinato, Jacopo; Ragazzoni, Roberto; Arcidiacono, Carmelo; Brunelli, Alessandro; Dima, Marco; Gentile, G.; Viotto, Valentina; Diolaiti, Emiliano; Foppiani, Italo; Lombini, Matteo; Schreiber, Laura; Bizenberger, Peter; Bonis, Fulvio De; Egner, Sebastian; Gässler, W.; Herbst, Tom; Kürster, M.; Mohr, Lars; Rohloff, Ralf-Rainer

doi:10.1117/12.790401

Cited by 13 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…21 Wavefront sensing is performed using multiple pyramids, which acquire multiple NGSs from two different FoVs. [22][23][24] In addition, the design follows the layer-oriented scheme, which foresees the optical co-addition of the star footprints at the WFS, minimizing the read noise penalty and allowing fainter stars to be used for the sensing (as long as the total flux corresponds to the limiting magnitude for correction). We define footprint as the projection of the telescope pupil through which the starlight passes at a given altitude.…”

Section: Partial Illumination Issue In the Context Of The Linc-nirvanmentioning

confidence: 99%

Operation of a layer-oriented multiconjugate adaptive optics system in the partial illumination regime

Santhakumari

Arcidiacono

Bertram

et al. 2019

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

Multiconjugate adaptive optics (MCAO) promises uniform wide-field atmospheric correction. However, partial illumination of the layers at which the deformable mirrors are conjugated results in incomplete information about the full turbulence field. We report on a working solution to this difficulty for layer-oriented MCAO, including laboratory and on-sky demonstration with the LINC-NIRVANA instrument at the Large Binocular Telescope. This approach has proven to be simple and stable.

show abstract

Section: Partial Illumination Issue In the Context Of The Linc-nirvanmentioning

confidence: 99%

Operation of a layer-oriented multiconjugate adaptive optics system in the partial illumination regime

Santhakumari

Arcidiacono

Bertram

et al. 2019

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

show abstract

“…All the considerations carried out in the previous section leads to the concept, already explored in other contexts, to segment the Field of View, once it has been corrected for the ground layer disturbance by the Adaptive Secondary Mirror [12] properly driven in order to achieve the best correction for the full ensemble of the split Field of Views [13,14] . This is depicted in Fig.1 in the usual turbulence diagram with altitude and spatial frequency in the two axes.…”

Section: Segmenting the Field Of Viewmentioning

confidence: 99%

Hierarchichal-segmented AO in order to attain wide field compensation in the visible on an 8m class telescope.

Ragazzoni¹,

Magrin²,

Farinato³

et al. 2017

Proceedings of the Adaptive Optics for Extremely Large Telescopes 5

View full text Add to dashboard Cite

We describe the preliminary optimized layout for a partially optimized concept of an optical-8m class VLT-like 2x2 segmented camera where each channel is assisted by an equivalent of an MCAO system where the ground layer correction is commonly employed while the high altitude ones is performed in an open-loop fashion. While we derive the basic relationships among the Field of View and attainable correction with a pre-defined choice for the hardware, we discuss sky coverage and wavefront sensing issues employing natural and artificial references, involving the latest stateof-the-art in the development of wavefront sensing. We show that a flexible approach allow for a compensated Field of View that is variable and can be properly tuned matching the current turbulence situation and the requirement in term of quality of the compensation. A preliminary description of the overall optomechanical package is given as well along with a rough estimates of the efforts required to translates such a concept into reality.

show abstract

“…This technique foresees to use, for the wavefront sensing phase at the level of the ground layer, the light collected in an annular field of view, letting the central part of the Field of View go to the MHWS (Mid-High Wavefront Sensor), and in this way use the light more efficiently [5]. It consists of two identical units, each placed on the optical path of the beam coming from the tertiary mirrors of LBT.…”

Section: Introductionmentioning

confidence: 99%

Aligning a more than 100 degrees of freedom wavefront sensor

et al. 2012

View full text Add to dashboard Cite

LINC-NIRVANA is the Fizeau beam combiner for the LBT, with the aim to retrieve the sensitivity of a 12m telescope and the spatial resolution of a 22.8m one. Despite being only one of the four wavefront sensors of a layer-oriented MCAO system, the GWS, which is retrieving the deformation introduced by the lower atmosphere, known to be the main aberration source, requires a noticeable internal opto-mechanical complexity. The presence of 12 small devices used to select up to the same number of NGSs, with 3 optical components each, moving in a wide annular 2'-6' arcmin Field of View and sending the light to a common pupil re-imager, and the need to obtain and keep a very good superposition of the pupil images on the CCD camera, led to an overall alignment procedure in which more than a hundred of degrees of freedom have to be contemporary adjusted. Moreover, rotation of the entire WFS to compensate for sky movement introduces further difficulties, alignment and in ensuring stability of the required pupil superposition. A detailed description of the alignment procedure is presented here, together with the lessons learned managing the complexity of such a WFS, which led to considerations regarding future instruments, like a possible review of numerical versus optical co-add approach, above all if close to zero read-out noise detectors will be soon available. Nevertheless, the GWS AIV has been carried out and the system will be soon mounted at LBT to perform what is called the Pathfinder experiment, which consists in ground-layer correction, taking advantage of the Adaptive Secondary deformable Mirror.

show abstract

The Multiple Field of View Layer Oriented wavefront sensing system of LINC-NIRVANA: two arcminutes of corrected field using solely Natural Guide Stars

Cited by 13 publications

References 13 publications

Operation of a layer-oriented multiconjugate adaptive optics system in the partial illumination regime

Operation of a layer-oriented multiconjugate adaptive optics system in the partial illumination regime

Hierarchichal-segmented AO in order to attain wide field compensation in the visible on an 8m class telescope.

Aligning a more than 100 degrees of freedom wavefront sensor

Contact Info

Product

Resources

About