&lt;title&gt;Image quality and active optics for the Gran Telescopio Canarias&lt;/title&gt;

Castro, Jordi; Bello, C. Delores; Jochum, Lotti; Devaney, Nicholas

doi:10.1117/12.319260

Cited by 11 publications

(6 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…18 The amount of piston errors is = 0.3 rad, which corresponds to 24 nm ͑ Ϸ 500 nm͒, which is within the range expected for the Gran Telescopio Canarias ͑GTC͒ telescope. 19 As previously stated, the telescope pupil is represented by an array with 512 512 samples, and the PSF is calculated as the squared modulus of the Fourier transform of the pupil function. An example of the application of amplitude masks to a telescope with piston errors is shown in Fig.…”

Section: Effect Of Piston Errorsmentioning

confidence: 99%

Reduction of the diffraction pattern in segmented apertures

et al. 2006

View full text Add to dashboard Cite

New discoveries in astronomy require the use of ever larger telescopes. These telescopes require segmented apertures, since current technology does not provide for the fabrication of monolithic mirrors with diameters much larger than 8 m. As a result, the point spread function ͑PSF͒ of the system presents a diffraction pattern characteristic of the segmentation geometry, and this complicates the task of detecting faint structures with high spatial resolution. In this work, we investigate the use of amplitude filters at the pupil plane to decrease the intensity of this diffraction pattern. It is sufficient if this diffraction pattern is reduced below the residual halo that remains after adaptive optics compensation, so that the intensity distribution that surrounds the PSF core is limited by scattering rather than diffraction. We show different kinds of filters that allow us to achieve this goal. We analyze their performance, taking into account some unavoidable errors in the telescope operation such as imperfect phasing of the telescope segments and gaps between them. Finally, we discuss the application of the technique considering errors in the adaptive optics correction.

show abstract

Section: Effect Of Piston Errorsmentioning

confidence: 99%

Reduction of the diffraction pattern in segmented apertures

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Additionally, the relative Piston is estimated by measuring the PSF of the Shack-Hartmann lens-lets placed at the M1 segment interface image. The last is the core of the Gary Chanan Keck co-phasing algorithms 7 . A modified version of the Keck narrow band algorithm will be used at the GTC 8 .…”

Section: Introductionmentioning

confidence: 99%

The commissioning instrument for the Gran Telescopio Canarias: made in Mexico

et al. 2006

Self Cite

View full text Add to dashboard Cite

In March 2004 was accepted in the site of Gran Telescopio Canarias (GTC) in La Palma Island, Spain, the Commissioning Instrument (CI) for the GTC. During the GTC integration phase, the CI will be a diagnostic tool for performance verification. The CI features four operation modes-imaging, pupil imaging, Curvature Wave-front sensing (WFS), and high resolution Shack-Hartmann WFS. This instrument was built by the Instituto de Astronomía UNAM in México City and the Centro de Ingeniería y Desarrollo Industrial (CIDESI) in Querétaro, Qro under a GRANTECAN contract after an international public bid. Some optical components were built by Centro de Investigaciones en Óptica (CIO) in León Gto and the biggest mechanical parts were manufactured by Vatech in Morelia Mich. In this paper we made a general description of the CI and we relate how this instrument, build under international standards, was entirely made in Mexico.

show abstract

“…The CI needs a reasonably large field of view to spot objects with the un-calibrated working pointing model 4 . Likewise, the CI's image quality identifies error sources helping to correct image degradation.…”

Section: Introductionmentioning

confidence: 99%

Site acceptance of the commissioning instrument for the Gran Telescopio Canarias

Cuevas¹,

Sánchez²,

Bringas

et al. 2006

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

In March 2004, the Commissioning Instrument (CI) for the GTC was accepted in the site of The Gran Telescopio Canarias (GTC) located in La Palma Island, Spain. During the GTC integration phase, the CI will be a diagnostic tool for performance verification. The CI features four operation modes-imaging, pupil imaging, Curvature Wave-front sensing (WFS), and high resolution Shack-Hartmann WFS. The imaging mode permits to qualify the GTC image quality. The Pupil Mode permits estimate the GTC stray light. The segments figure, alignment and cophasing verifications are made with both WFS modes. In this work we describe the Commissioning Instrument and show some tests results obtained during the site acceptance process at the GTC site.

show abstract

<title>Image quality and active optics for the Gran Telescopio Canarias</title>

Cited by 11 publications

References 5 publications

Reduction of the diffraction pattern in segmented apertures

Reduction of the diffraction pattern in segmented apertures

The commissioning instrument for the Gran Telescopio Canarias: made in Mexico

Site acceptance of the commissioning instrument for the Gran Telescopio Canarias

Contact Info

Product

Resources

About