GTCAO LGS. Adaptative Optics and Laser Guide Star for GTC


GTCAO (Adaptive Optics system for GTC) is a post-focus system located on the Nasmyth B platform of the telescope, which corrects the effect of the atmospheric turbulence on the light coming from the telescope and feeds the scientific instrument placed after it, thus allowing to carry out high spatial resolution science. GTCAO follows the classic design of an AO (Adaptive Optics) system with the use of two identical off-axis parabolas, maintaining the effective focal distance of the telescope. On Day 1, the system will provide a single deformable mirror conjugated to the telescope pupil and will use natural stars (NGS) for wavefront sensing.

The GTCAO system is expected to provide a corrected beam that will achieve a Strehl ratio of 0.65 in K-band with bright guide stars. The size of the transmitted field of view is 1.5 arcmin diameter and the optical layout of the system has been designed to be able to include, in the future, an atmospheric dispersion corrector (ADC) working up to 60º zenith angle in order not to degrade its performance with increasing zenith angle.

GTCAO employs a wavefront sensor of Shack-Hartmann type with 20x20 subapertures and a deformable mirror with 21x21 actuators. For tip-tilt correction it uses the GTC secondary mirror.

Future and planned upgrades will allow the system to increase the sky coverage, by the use of a Sodium laser guide star, LGS, and also to increase the size of the corrected field of view, by adding an additional wavefront corrector and a second deformable mirror conjugated to an altitude of approximately 10 Km. The LGS upgrade is already under development.

The first scientific instrument to use GTCAO will be FRIDA (inFRared Imager and Dissector for Adaptive optics), an integral field spectrograph in the near infrared with imaging capability.

Note: This project was partially funded by the European Regional Development Fund (ERDF) under the Programa Operativo de Canarias 2007-2013, Axis 1, Priority Theme 2, under Resolution No. 364 of November 25, 2014 of the Canarian Agency for Research, Innovation and Information Society (ACIISI), and under the Programa Operativo de Canarias 2014-2020, "Canarias objetivo de progreso".

Principal investigator
Project manager
Project staff

Publications related

No related publications were found.

Talks related

No related talks were found.

Conferences related

No related conferences were found.
Related projects
Image of the first optical alingment of FRIDA
FRIDA - inFRared Imager and Dissector for Adaptive optics

FRIDA (inFRared Imager and Dissector for Adaptive optics) is an integral field spectrograph in the near infrared, also with image mode, which will be installed in the GTC telescope. It will use the adaptive optics system of GTC (GTCAO) to observe with very high spatial resolution and spectral resolutions of up to 30,000.

M Almudena
Prieto Escudero
Related installation

Related news

  • Folleto GTC 10 aniversario

    The Gran Telescopio Canarias (GTC) is celebrating the tenth anniversary of its inauguration in the Roque de Los Muchachos Observatory. During the past decade the largest optical and infrared telescope in the world has carried out over 14,000 hours of observation and has produced scientific data in some 450 articles in the leading journals. Some of the key scientific highlights have been included in a special outreach leaflet recently published by the Instituto de Astrofísica de Canarias and the GTC.

    Advertised on