Download or read book Image Ellipticity from Atmospheric Aberrations written by and published by . This book was released on 2007 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand the errors in shape measurements of astronomical objects, such as those used to study weak gravitational lensing of field galaxies. The PSF modeling involves either a Fourier transform of the phase information in the pupil plane or a ray-tracing approach, which has the advantage of requiring fewer computations than the Fourier transform. Using a standard method, involving the Gaussian weighted second moments of intensity, we then calculate the ellipticity of the PSF patterns. We find significant ellipticity for the instantaneous patterns (up to more than 10%). Longer exposures, which we approximate by combining multiple (N) images from uncorrelated atmospheric realizations, yield progressively lower ellipticity (as 1/(square root)N). We also verify that the measured ellipticity does not depend on the sampling interval in the pupil plane using the Fourier method. However, we find that the results using the ray-tracing technique do depend on the pupil sampling interval, representing a gradual breakdown of the geometric approximation at high spatial frequencies. Therefore, ray tracing is generally not an accurate method of modeling PSF ellipticity induced by atmospheric turbulence unless some additional procedure is implemented to correctly account for the effects of high spatial frequency aberrations. The Fourier method, however, can be used directly to accurately model PSF ellipticity, which can give insights into errors in the statistics of field galaxy shapes used in studies of weak gravitational lensing.
Download or read book Reviews in astronomy and space sciences written by Christopher H. K. Chen and published by Frontiers Media SA. This book was released on 2024-05-24 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Image Propagation Through the Atmosphere written by J. C. Dainty and published by SPIE-International Society for Optical Engineering. This book was released on 1996 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical Determination of Geometrical Image Aberrations in Single and Double mirror Systems written by Martin G. Hurwitz and published by . This book was released on 1968 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Imaging and Aberrations written by Virendra N. Mahajan and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Digital Image Recovery and Synthesis written by and published by . This book was released on 1996 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Imaging Sensors and Technologies written by Gonzalo Pajares Martinsanz and published by MDPI. This book was released on 2018-07-06 with total page 635 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Imaging: Sensors and Technologies" that was published in Sensors
Download or read book The NOT in the 2000 s written by Nils Bergvall and published by . This book was released on 2000 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gravitational Lensing written by Scott Dodelson and published by Cambridge University Press. This book was released on 2017-06-08 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gravitational lensing is a consequence of general relativity, where the gravitational force due to a massive object bends the paths of light originating from distant objects lying behind it. Using very little general relativity and no higher level mathematics, this text presents the basics of gravitational lensing, focusing on the equations needed to understand the phenomena. It then applies them to a diverse set of topics, including multiply imaged objects, time delays, extrasolar planets, microlensing, cluster masses, galaxy shape measurements, cosmic shear, and lensing of the cosmic microwave background. This approach allows undergraduate students and others to get quickly up to speed on the basics and the important issues. The text will be especially relevant as large surveys such as LSST and Euclid begin to dominate the astronomical landscape. Designed for a one semester course, it is accessible to anyone with two years of undergraduate physics background.
Download or read book Geodetic Glossary written by National Geodetic Survey (U.S.) and published by . This book was released on 1986 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Missions to the Moon and Exploring the Cold Universe written by COSPAR. Scientific Commission E. E1 Symposium and published by . This book was released on 1996 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Astronomical Instrumentation written by and published by . This book was released on 1998 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mantles of the Earth and Terrestrial Planets written by S. K. Runcorn and published by . This book was released on 1967 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Course of Lectures on Natural Philosophy and the Mechanical Arts written by Thomas Young and published by . This book was released on 1807 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact of Gravitational Lensing on Cosmology IAU S225 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2005-09-05 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the International Astronomical Union Symposium no. 225, held in July 2004 at the Ecole Polytechnique Federale de Lausanne (EPFL), in Lausanne, Switzerland. The meeting focused on the applications of gravitational lensing to cosmological physics, and this book summarizes the most recent theoretical and observational developments. With chapters written by leading scientists in the field, this is a valuable resource for professional astronomers and graduate students in astronomy, physics and astro-particle physics.
Download or read book Physics of Light and Optics Black White written by Michael Ware and published by Lulu.com. This book was released on 2020 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science Abstracts written by and published by . This book was released on 1959 with total page 1478 pages. Available in PDF, EPUB and Kindle. Book excerpt:
