Download or read book Sodium Laser Guide Star Projection for Adaptive Optics written by Bruce Paul Jacobsen and published by . This book was released on 1997 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This dissertation will detail the concept, development, and prototype development and performance of a sodium laser projection system developed for the 6.5m telescope destined to replace the current MMT"--P. 21.

Download or read book Laser Guide Star Adaptive Optics for Astronomy written by N. Ageorges and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics allows the theoretical limit of angular resolution to be achieved from a large telescope, despite the presence of turbulence. Thus an eight meter class telescope, such as one of the four in the Very Large Telescope operated by ESO in Chile, will in future be routinely capable of an angular resolution of almost 0.01 arcsec, compared tot he present resolution of about 0.5 arcsec for conventional imaging in good condition. All the world's major telescopes either have adaptive optics or are in the process of building AO systems. It turns out that a reasonable fraction of the sky can be observed using adaptive optics, with moderately good imaging quality, provided imaging in done in the near IR. To move out of the near IR, with its relatively poor angular resolution, astronomers need a laser guide star. There is a layer of Na atoms at approximately 90 km altitude that can be excited by a laser to produce such a source, or Rayleigh scattering can be employed lower in the atmosphere. But the production and use of laser guide stars is not trivial, and the key issues determining their successful implementation are discussed here, including the physics of the Na atom, the cone effect, tilt determination, sky coverage, and numerous potential astronomical applications.

Download or read book Sodium Laser Guide Star Technique Spectroscopy and Imaging with Adaptive Optics PHD written by Ge Jian and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Image Improvement from a Sodium layer Laser Guide Star Adaptive Optics System written by and published by . This book was released on 1997 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: A sodium-layer laser guide star beacon with high-order adaptive optics at Lick Observatory produced a factor of 2.4 intensity increase and a factor of 2 decrease in full width at half maximum for an astronomical point source, compared with image motion compensation alone. Image full widths at half maximum were identical for laser and natural guide stars (0.3 arc seconds). The Strehl ratio with the laser guide star was 65% of that with a natural guide star. This technique should allow ground-based telescopes to attain the diffraction limit, by correcting for atmospheric distortions.

Download or read book Lusser Franz Vital 1849 1927 written by and published by . This book was released on 1927 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Sodium Laser Guide Star Experiment for Adaptive Optics and the Development of a High Bandwidth Tracking System for the University of Chicago Adaptive Optics System written by Fang Shi and published by . This book was released on 1999 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Guide Stars and Adaptive Optics for Astronomy written by and published by . This book was released on 1992 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five papers are included: feasibility experiment for sodium-alyer laser guide stars at LLNL; system design for a high power sodium beacon laser; sodium guide star adaptive optics system for astronomical imaging in the visible and near-infrared; high frame-rate, large field wavefront sensor; and resolution limits for ground-based astronomical imaging. Figs, tabs, refs.

Download or read book Sodium Laser Guide Star Adaptive Optics Imaging Polarimetry of Herbig Ae Be Stars written by and published by . This book was released on 2004 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The future of high-resolution ground-based optical and infrared astronomy requires the successful implementation of laser guide star adaptive optics systems. We present the first science results from the Lick Observatory sodium beacon laser guide star system. By coupling this system to a near-infrared (J;H;Ks bands) dual-channel imaging polarimeter, we achieve very high sensitivity to light scattered in the circumstellar enviroment of Herbig Ae/Be stars on scales of 100-300 AU. Observations of LkH[alpha] 198 reveal a highly polarized, biconical nebula 10 arcseconds in diameter (6000 AU) . We also observe a polarized jet-like feature associated with the deeply embedded source LkH[alpha] 198-IR. The star LkH[alpha] 233 presents a narrow, unpolarized dark lane dividing its characteristic butterfly-shaped polarized reflection nebulosity. This linear structure is oriented perpendicular to an optical jet and bipolar cavity and is consistent with the presence of an optically thick circumstellar disk blocking our direct view of the star. These data suggest that the evolutionary picture developed for the lower-mass T Tauri stars is also relevant to the Herbig Ae/Be stars and demonstrate the ability of laser guide star adaptive optics systems to obtain scientific results competitive with natural guide star adaptive optics or space-based telescopes.

Download or read book Performance of Laser Guide Star Adaptive Optics at Lick Observatory written by and published by . This book was released on 1995 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A sodium-layer laser guide star adaptive optics system has been developed at Lawrence Livermore National Laboratory (LLNL) for use on the 3-meter Shane telescope at Lick Observatory. The system is based on a 127-actuator continuous-surface deformable mirror, a Hartmann wavefront sensor equipped with a fast-framing low-noise CCD camera, and a pulsed solid-state-pumped dye laser tuned to the atomic sodium resonance line at 589 nm. The adaptive optics system has been tested on the Shane telescope using natural reference stars yielding up to a factor of 12 increase in image peak intensity and a factor of 6.5 reduction in image full width at half maximum (FWHM). The results are consistent with theoretical expectations. The laser guide star system has been installed and operated on the Shane telescope yielding a beam with 22 W average power at 589 nm. Based on experimental data, this laser should generate an 8th magnitude guide star at this site, and the integrated laser guide star adaptive optics system should produce images with Strehl ratios of 0.4 at 2.2 [mu]m in median seeing and 0.7 at 2.2 [mu]m in good seeing.

Download or read book Adaptive Optics Engineering Handbook written by Robert Tyson and published by CRC Press. This book was released on 1999-11-10 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook supplies analytical tools for the design and development of adaptive optics systems to enhance their ability to adjust for atmospheric turbulence, optical fabrication errors, thermally induced distortions, and laser device aberrations. It provides recommendations for selecting, testing and installing a wavefront compensation system.

Download or read book Initial Results from the Lick Observatory Laser Guide Star Adaptive Optics System written by and published by . This book was released on 1995 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present initial results from the sodium-layer laser guide star adaptive optics system developed for the 3-m Shane telescope at Lick Observatory.

Download or read book Design and Early Results of the Sodium layer Laser Guide Star Adaptive Optics Experiment at the Lawrence Livermore National Laboratory written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optic systems promise to give diffraction limited performance to ground based telescopes operating at visible and near infrared wavelengths. However, because of the short spatial scale of atmospheric turbulence, the corrected field of view is limited to only a few arc seconds in the visible, to perhaps 10 arc seconds at L band (3.5 [mu]). A bright point source must be in this field of view as a wavefront reference, but the number density of natural stars is too small for full sky coverage at imaging wavelengths less than 3[mu]. A sufficiently bright point source can be artificially generated by a laser however, and investigations into the use of laser beacons has been proceeding for some time now. Our experiments at Livermore have concentrated on the formation of guide stars in the sodium mesospheric layer at 90 km altitude. We have also designed and built adaptive optics systems that use both artificial and natural guide stars. Experimental results to date have shown great promise for the practicality of this technique in astronomy.

Download or read book Novel Adaptive Optics Concepts written by Stephan Kellner and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observing Techniques for Astronomical Laser Guide Star Adaptive Optics written by and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss astronomical observing requirements and their implementation using sodium-layer laser guide star adaptive optics. Specific issues requiring implementation include the ability to place the astronomical object at different locations within the field of view; reliable subtraction of Rayleigh-scattered light; efficient focusing; and stable point-spread-function characterization.

Download or read book Improved Performance of the Laser Guide Star Adaptive Optics System at Lick Observatory written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of experiments with the laser guide star adaptive optics system on the 3-meter Shane telescope at Lick Observatory have demonstrated a factor of 4 performance improvement over previous results. Stellar images recorded at a wavelength of 2 [mu]m were corrected to over 40% of the theoretical diffraction-limited peak intensity. For the previous two years, this sodium-layer laser guide star system has corrected stellar images at this wavelength to ≈10% of the theoretical peak intensity limit. After a campaign to improve the beam quality of the laser system, and to improve calibration accuracy and stability of the adaptive optics system using new techniques for phase retrieval and phase-shifting diffraction interferometry, the system performance has been substantially increased. The next step will be to use the Lick system for astronomical science observations, and to demonstrate this level of performance with the new system being installed on the 10-meter Keck II telescope.

Download or read book Principles of Adaptive Optics written by Robert Tyson and published by CRC Press. This book was released on 2010-09-14 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the second edition of Principles of Adaptive Optics, the developments and applications in this area have increased tremendously. Observatories are now producing outstanding science through adaptive optics technology; components, such as micromachined deformable mirrors and very low noise detectors, are revolutionizing the f

Download or read book Laser Guide Star Adaptive Optics Program LGSAOP written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lawrence Livermore National Laboratory of Livermore, California, presents information on its Laser Guide Star Adaptive Optics Program (LGSAOP). The focus of the project is the development of integrated adaptive optics (AO) and sodium-layer laser guide star (LGS) systems for use on large astronomical telescopes.