26,567 research outputs found
Adaptive Optics for Astronomy
Adaptive Optics is a prime example of how progress in observational astronomy
can be driven by technological developments. At many observatories it is now
considered to be part of a standard instrumentation suite, enabling
ground-based telescopes to reach the diffraction limit and thus providing
spatial resolution superior to that achievable from space with current or
planned satellites. In this review we consider adaptive optics from the
astrophysical perspective. We show that adaptive optics has led to important
advances in our understanding of a multitude of astrophysical processes, and
describe how the requirements from science applications are now driving the
development of the next generation of novel adaptive optics techniques.Comment: to appear in ARA&A vol 50, 201
PASSATA - Object oriented numerical simulation software for adaptive optics
We present the last version of the PyrAmid Simulator Software for Adaptive
opTics Arcetri (PASSATA), an IDL and CUDA based object oriented software
developed in the Adaptive Optics group of the Arcetri observatory for
Monte-Carlo end-to-end adaptive optics simulations. The original aim of this
software was to evaluate the performance of a single conjugate adaptive optics
system for ground based telescope with a pyramid wavefront sensor. After some
years of development, the current version of PASSATA is able to simulate
several adaptive optics systems: single conjugate, multi conjugate and ground
layer, with Shack Hartmann and Pyramid wavefront sensors. It can simulate from
8m to 40m class telescopes, with diffraction limited and resolved sources at
finite or infinite distance from the pupil. The main advantages of this
software are the versatility given by the object oriented approach and the
speed given by the CUDA implementation of the most computational demanding
routines. We describe the software with its last developments and present some
examples of application.Comment: 9 pages, 2 figures, 3 tables. SPIE conference Astronomical Telescopes
and Instrumentation, 26 June - 01 July 2016, Edinburgh, Scotland, United
Kingdo
Adaptive Optics for Extremely Large Telescopes
Adaptive Optics has become a key technology for the largest ground-based
telescopes currently under or close to begin of construction. Adaptive optics
is an indispensable component and has basically only one task, that is to
operate the telescope at its maximum angular resolution, without optical
degradations resulting from atmospheric seeing. Based on three decades of
experience using adaptive optics usually as an add-on component, all extremely
large telescopes and their instrumentation are designed for diffraction limited
observations from the very beginning. This review illuminates the various
approaches of the Extremely Large Telescope, the Giant Magellan Telescope, and
the Thirty-Meter Telescope, to fully integrate adaptive optics in their
designs. The article concludes with a brief look into the requirements that
high-contrast imaging poses on adaptive optics.Comment: 29 pages, 13 figures, published in Journal of Astronomical
Instrumentation, November 2, 201
Atmospheric tomography with separate minimum variance laser and natural guide star mode control
This paper introduces a novel, computationally efficient, and practical atmospheric tomography wavefront control architecture with separate minimum variance laser and natural guide star mode estimation. The architecture is applicable to all laser tomography systems, including multi conjugate adaptive optics (MCAO), laser tomography adaptive optics (LTAO), and multi object adaptive optics (MOAO) systems. Monte Carlo simulation results for the Thirty Meter Telescope (TMT) MCAO system demonstrate its benefit over a previously introduced “ad hoc” split MCAO architecture, calling for further in-depth analysis and simulations over a representative ensemble of natural guide star (NGS) asterisms with optimized loop frame rates and modal gains
Simulations of Adaptive Optics with a Laser Guide Star for SINFONI
The SINFONI instrument for ESO's VLT combines integral field spectroscopy and
adaptive optics (AO). We discuss detailed simulations of the adaptive optics
module. These simulations are aimed at assessing the AO module performance,
specifically for operations with extended sources and a laser guide star.
Simulated point spread function (PSF) images will be used to support scientific
preparations and the development of an exposure time calculator, while
simulated wavefront sensor measurements will be used to study PSF
reconstruction methods. We explain how the adaptive optics simulations work,
focusing on the realistic modelling of the laser guide star for a curvature
wavefront sensor. The predicted performance of the AO module is discussed,
resulting in recommendations for the operation of the SINFONI AO module at the
telescope.Comment: 12 pages, 6 figures, to appear in SPIE conference proceedings vol
5490, "Advancements in Adaptive Optics", eds. D. Bonaccini, B.L. Ellerbroek,
R. Ragazonni, Glasgow UK, 21-25 June 200
On-sky results of the adaptive optics MACAO for the new IR-spectrograph CRIRES at VLT
The adaptive optics MACAO has been implemented in 6 focii of the VLT
observatory, in three different flavors. We present in this paper the results
obtained during the commissioning of the last of these units, MACAO-CRIRES.
CRIRES is a high-resolution spectrograph, which efficiency will be improved by
a factor two at least for point-sources observations with a NGS brighter than
R=15. During the commissioning, Strehl exceeding 60% have been observed with
fair seeing conditions, and a general description of the performance of this
curvature adaptive optics system is done.Comment: SPIE conference 2006, Advances in adaptive optics, 12 pages, 11
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