The adaptive optics modes for HARMONI: from Classical to Laser Assisted Tomographic AO

HARMONI is a visible and NIR integral field spectrograph, providing the E-ELT’s core spectroscopic capability at first light. HARMONI will work at the diffraction limit of the E-ELT, thanks to a Classical and a Laser Tomographic AO system. In this paper, we present the system choices that have been made for these SCAO and LTAO modules. In particular, we describe the strategy developed for the different Wave-Front Sensors: pyramid for SCAO, the LGSWFS concept, the NGSWFS path, and the truth sensor capabilities. We present first potential implementations. And we asses the first system performance.

[1]  Kjetil Dohlen,et al.  Laser guide star spot shrinkage for affordable wavefront sensors , 2016, Astronomical Telescopes + Instrumentation.

[2]  Ronald Holzlöhner,et al.  Statistics of the sodium layer parameters at low geographic latitude and its impact on adaptive-optics sodium laser guide star characteristics , 2010 .

[3]  Johan Kosmalski,et al.  HARMONI: a single-field wide-band integral-field spectrograph for the European ELT , 2010, Astronomical Telescopes + Instrumentation.

[4]  Emiliano Diolaiti,et al.  Accurate laser guide star wavefront sensor simulation for the E-ELT first light adaptive optics module , 2016, Astronomical Telescopes + Instrumentation.

[5]  Pierre-Yves Madec,et al.  Simulations of E-ELT telescope effects on AO system performance , 2016, Astronomical Telescopes + Instrumentation.

[6]  D. Pipa,et al.  Improving centroiding by super-resolution reconstruction of sodium layer density in Shack-Hartmann wavefront sensors. , 2016, Applied optics.

[7]  Carlos Correia,et al.  Object-oriented Matlab adaptive optics toolbox , 2014, Astronomical Telescopes and Instrumentation.

[8]  Eric Gendron.  Optical solutions for accommodating ELT LGS wave-front sensing to small format detectors , 2016, Astronomical Telescopes + Instrumentation.

[9]  Benoit Neichel,et al.  Natural guide-star processing for wide-field laser-assisted AO systems , 2016, Astronomical Telescopes + Instrumentation.

[10]  Johan Kosmalski,et al.  The E-ELT first light spectrograph HARMONI: capabilities and modes , 2016, Astronomical Telescopes + Instrumentation.

[11]  Sarah J. Diggs,et al.  Gemini multiconjugate adaptive optics system review – II. Commissioning, operation and overall performance , 2014, 1402.6906.

[12]  Isabelle Tallon-Bosc,et al.  Shack-Hartmann wavefront reconstruction with elongated sodium laser guide stars: improvements with priors and noise correlations , 2008, Astronomical Telescopes + Instrumentation.

[13]  Alastair Basden,et al.  Novel algorithm implementations in DARC: the Durham AO real-time controller , 2016, Astronomical Telescopes + Instrumentation.

[14]  Elena Masciadri,et al.  3D mapping of optical turbulence using an atmospheric numerical model - I. A useful tool for the ground-based astronomy , 1999 .