Download or read book Practical High Order Adaptive Optics Systems For Extrasolar Planet Searches written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct detection of photons emitted or reflected by an extrasolar planet is an extremely difficult but extremely exciting application of adaptive optics. Typical contrast levels for an extrasolar planet would be 109-Jupiter is a billion times fainter than the sun. Current adaptive optics systems can only achieve contrast levels of 106, but so-called ''extreme'' adaptive optics systems with 104-105 degrees of freedom could potentially detect extrasolar planets. We explore the scaling laws defining the performance of these systems, first set out by Angel (1994), and derive a different definition of an optimal system. Our sensitivity predictions are somewhat more pessimistic than the original paper, due largely to slow decorrelation timescales for some noise sources, though choosing to site an ExAO system at a location with exceptional r0 (e.g. Mauna Kea) can offset this. We also explore the effects of segment aberrations in a Keck-like telescope on ExAO; although the effects are significant, they can be mitigated through Lyot coronagraphy.
Download or read book Adaptive Optics for Direct Detection of Extrasolar Planets written by and published by . This book was released on 2007 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The direct detection of photons emitted or reflected by extrasolar planets, spatially resolved from their parent star, is a major frontier in the study of other solar systems. Direct detection will provide statistical information on planets in 5-50 AU orbits, inaccessible to current Doppler searches, and allow spectral characterization of radius, temperature, surface gravity, and perhaps composition. Achieving this will require new dedicated high-contrast instruments. One such system under construction is the Gemini Planet Imager (GPI.) This combines a high-order/high-speed adaptive optics system to control wavefront errors from the Earth's atmosphere, an advanced coronagraph to block diffraction, ultrasmooth optics, a precision infrared interferometer to measure and correct systematic errors, and a integral field spectrograph/polarimeter to image and characterize target planetary systems. We predict that GPI will be able to detect planets with brightness less than 10−7 of their parent star, sufficient to observe warm self-luminous planets around a large population of targets.
Download or read book Adaptive Optics Systems and Technology written by and published by . This book was released on 2002 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Optics for Astronomy written by D.M. Alloin and published by Springer Science & Business Media. This book was released on 1994-03-31 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: The blossoming of adaptive optical techniques has brought about a revolution in the field of astronomical observation. Coupled with the new generation of large, ground-based telescopes, it allows us to achieve an unprecendented angular resolution in the analysis of faint astronomical sources at optical wavelengths. This book provides the basic concepts of adaptive optics, discusses the possible instrumental strategies and the state-of-the-art technical achievements of this development and presents the key astrophysical programs which will most benefit from it. Over fifteen well-known experts have contributed to making this volume a comprehensive one, with steady progression as well as full coverage of the various aspects of the field. Students graduating in optical sciences and astrophysics, astronomers, engineers interested in atmospheric turbulence compensation will find this book a reference text on the subject.
Download or read book Journal of the Optical Society of America written by and published by . This book was released on 2004 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Optics for Vision Science written by Jason Porter and published by John Wiley & Sons. This book was released on 2006-06-12 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading experts present the latest technology and applications in adaptive optics for vision science Featuring contributions from the foremost researchers in the field, Adaptive Optics for Vision Science is the first book devoted entirely to providing the fundamentals of adaptive optics along with its practical applications in vision science. The material for this book stems from collaborations fostered by the Center for Adaptive Optics, a consortium of more than thirty universities, government laboratories, and corporations. Although the book is written primarily for researchers in vision science and ophthalmology, the field of adaptive optics has strong roots in astronomy. Researchers in both fields share this technology and, for this reason, the book includes chapters by both astronomers and vision scientists. Following the introduction, chapters are divided into the following sections: * Wavefront Measurement and Correction * Retinal Imaging Applications * Vision Correction Applications * Design Examples Readers will discover the remarkable proliferation of new applications of wavefront-related technologies developed for the human eye. For example, the book explores how wavefront sensors offer the promise of a new generation of vision correction methods that can deal with higher order aberrations beyond defocus and astigmatism, and how adaptive optics can produce images of the living retina with unprecedented resolution. An appendix includes the Optical Society of America's Standards for Reporting Optical Aberrations. A glossary of terms and a symbol table are also included. Adaptive Optics for Vision Science arms engineers, scientists, clinicians, and students with the basic concepts, engineering tools, and techniques needed to master adaptive optics applications in vision science and ophthalmology. Moreover, readers will discover the latest thinking and findings from the leading innovators in the field.
Download or read book MEMS based Extreme Adaptive Optics for Planet Detection written by J. R. Graham and published by . This book was released on 2005 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The next major step in the study of extrasolar planets will be the direct detection, resolved from their parent star, of a significant sample of Jupiter-like extrasolar giant planets. Such detection will open up new parts of the extrasolar planet distribution and allow spectroscopic characterization of the planets themselves. Detecting Jovian planets at 5-50 AU scale orbiting nearby stars requires adaptive optics systems and coronagraphs an order of magnitude more powerful than those available today--the realm of ''Extreme'' adaptive optics. We present the basic requirements and design for such a system, the Gemini Planet Imager (GPI.) GPI will require a MEMS-based deformable mirror with good surface quality, 2-4 micron stroke (operated in tandem with a conventional low-order ''woofer'' mirror), and a fully-functional 48-actuator-diameter aperture.
Download or read book Principles of Adaptive Optics written by Robert K. Tyson and published by CRC Press. This book was released on 2022-02-28 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Adaptive Optics describes the foundations, principles, and applications of adaptive optics (AO) and its enabling technologies. This leading textbook addresses the fundamentals of AO at the core of astronomy, high-energy lasers, biomedical imaging, and optical communications. Key Features: Numerous examples to explain and support the underlying principles Hundreds of new references to support the topics that are addressed End-of-chapter questions and exercises A complete system design example threaded through each chapter as new material is introduced
Download or read book High contrast Imaging Using Adaptive Optics for Extrasolar Planet Detection written by Julia Wilhelmsen Evans and published by . This book was released on 2006 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extreme Adaptive Optics for the Thirty Meter Telescope written by B. Macintosh and published by . This book was released on 2006 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct detection of extrasolar Jovian planets is a major scientific motivation for the construction of future extremely large telescopes such as the Thirty Meter Telescope (TMT). Such detection will require dedicated high-contrast AO systems. Since the properties of Jovian planets and their parent stars vary enormously between different populations, the instrument must be designed to meet specific scientific needs rather than a simple metric such as maximum Strehl ratio. We present a design for such an instrument, the Planet Formation Imager (PFI) for TMT. It has four key science missions. The first is the study of newly-formed planets on 5-10 AU scales in regions such as Taurus and Ophiucus--this requires very small inner working distances that are only possible with a 30m or larger telescope. The second is a robust census of extrasolar giant planets orbiting mature nearby stars. The third is detailed spectral characterization of the brightest extrasolar planets. The final targets are circumstellar dust disks, including Zodiacal light analogs in the inner parts of other solar systems. To achieve these, PFI combines advanced wavefront sensors, high-order MEMS deformable mirrors, a coronagraph optimized for a finely-segmented primary mirror, and an integral field spectrograph.
Download or read book Signal Processing for High precision Wavefront Control in Adaptive Optics written by Lisa Ann Poyneer and published by . This book was released on 2007 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Optics in Astronomy written by François Roddier and published by Cambridge University Press. This book was released on 1999-06-17 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics is set to revolutionise the future of astronomy; this is the first book on the subject and is set to become the standard reference.
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 EXtreme Adaptive Optics Planet Imager written by K. Wallace and published by . This book was released on 2004 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: As adaptive optics (AO) matures, it becomes possible to envision AO systems oriented towards specific important scientific goals rather than general-purpose systems. One such goal for the next decade is the direct imaging detection of extrasolar planets. An 'extreme' adaptive optics (ExAO) system optimized for extrasolar planet detection will have very high actuator counts and rapid update rates - designed for observations of bright stars - and will require exquisite internal calibration at the nanometer level. In addition to extrasolar planet detection, such a system will be capable of characterizing dust disks around young or mature stars, outflows from evolved stars, and high Strehl ratio imaging even at visible wavelengths. The NSF Center for Adaptive Optics has carried out a detailed conceptual design study for such an instrument, dubbed the eXtreme Adaptive Optics Planet Imager or XAOPI. XAOPI is a 4096-actuator AO system, notionally for the Keck telescope, capable of achieving contrast ratios>10{sup 7} at angular separations of 0.2-1'. ExAO system performance analysis is quite different than conventional AO systems - the spatial and temporal frequency content of wavefront error sources is as critical as their magnitude. We present here an overview of the XAOPI project, and an error budget highlighting the key areas determining achievable contrast. The most challenging requirement is for residual static errors to be less than 2 nm over the controlled range of spatial frequencies. If this can be achieved, direct imaging of extrasolar planets will be feasible within this decade.
Download or read book Adaptive Optics written by Michael S. Tarov and published by Nova Publishers. This book was released on 2002 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive optics is a field which is coming into its own with new discoveries occurring almost daily both in astronomy and in applications of AO in applied fields. In an adaptive optics system, the output from a wavefront sensor is used to calculate corrections that actively remove distortions from an image. The applications of adaptive optics in vision science have received considerable impetus from the knowledge developed by astronomers about how to correct images using AO technology. It is expected that developments in adaptive optics will radically change the face of astronomy in the 21st century. These systems will largely overcome the main limitation of ground-based telescopes, namely the severe reduction in image quality caused by turbulence in the Earth's atmosphere. Intended for use at near infrared wavelengths, adaptive optics allow imaging and spectroscopy at the limit of resolution imposed by optical diffraction an advance in astronomer's ability to view the heavens unparalleled since the invention of the telescope. AO is now also entering clinical medicine in the field of ophthalmology and other related fields. This new book presents several hundred current abstracts in the field, each fully indexed, for ease of access and contains a CD ROM for further research.
Download or read book Non redundant Aperture Masking Interferometry with Adaptive Optics written by David Wesley Bernat and published by . This book was released on 2012 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents my study of Non-Redundant Aperture Masking Interferometry (or NRM) with Adaptive Optics, a technique for obtaining high-contrast infrared images at diffraction-limited resolution. I developed numerical, statistical, and on-telescope techniques for obtaining higher contrast, in order to build an imaging system capable of resolving massive Jupiter analogs in tight orbits around nearby stars. I used this technique, combined with Laser Guide Star Adaptive Optics (LGSAO), to survey known brown dwarfs for brown dwarf and planetary companions. The diffraction-limited capabilities of this technique enable the detection of companions on short period orbits that make Keplerian mass measurement practical. This, in turn, provides mass and photometric measurements to test brown dwarf evolution (and atmosphere) models, which require empirical constraints to answer key questions and will form the basis for models of giant exoplanets for the next decade. I present the results of a close companion search around 16 known brown dwarf candidates (early L dwarfs) using the first application of NRM with LGSAO on the Palomar 200" Hale Telescope. The use of NRM allowed the detection of companions between 45-360 mas in Ks band, corresponding to projected physical separations of 0.6-10.0 AU for the targets of the survey. Due to unstable LGSAO correction, this survey was capable of detecting primary-secondary contrast ratios down to [INCREMENT]Ks ~1.5-2.5 (10:1), an order of magnitude brighter than if the system performed at specification. I present four candidate brown dwarf companions detected with moderate-to-high confidence (90%-98%), including two with projected physical separations less than 1.5 AU. A prevalence of brown dwarf binaries, if confirmed, may indicate that tight-separation binaries contribute to the total binary fraction more significantly than currently assumed, and make excellent candidates for dynamical mass measurement. For this project, I developed several new, robust tools to reject false positive detections, generate accurate contrast limits, and analyze NRM data in the low signal-to-noise regime. In order to increase the sensitivity of NRM, a critical and quantitative study of quasi-static wavefront errors needs to be undertaken. I investigated the impact of small-scale wavefront errors (those smaller than a sub-aperture) on NRM using a technique known as spatial filtering. Here, I explored the effects of spatial filtering through calculation, simulation, and observational tests conducted with an optimized pinhole and aperture mask in the PHARO instrument at the 200" Hale Telescope. I find that spatially filtered NRM can increase observation contrasts by 10-25% on current AO systems and by a factor of 2-4 on higher-order AO systems. More importantly, this reveals that small scale wavefront errors contribute only modestly to the overall limitations of the NRM technique without very high-order AO systems, and that future efforts need focus on temporal stability and wavefront errors on the scale of the sub-aperture. I also develop a formalism for optimizing NRM observations with these AO systems and dedicated exoplanet imaging instruments, such as Project 1640 and the Gemini Planet Imager. This work provides a foundation for future NRM exoplanet experiments.
Download or read book Advances in Adaptive Optics II written by and published by . This book was released on 2006 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
