Investigation of Atmospheric Laser Optics Test Bed (A_LOT) Optical Turbulence Intensity for Free-space Laser Communications
Author: Arnold Tunick
Publisher:
Published: 2006
Total Pages: 37
ISBN-13:
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Author: Arnold Tunick
Publisher:
Published: 2006
Total Pages: 37
ISBN-13:
DOWNLOAD EBOOKAuthor: Angel Fernandez
Publisher:
Published: 2016
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKAtmospheric turbulence, generated by a differential temperature between the Earth's surface and the atmosphere, causes effects on optical waves that have been of great interest to scientists for many years. Wave front distortions in the optical wave induced by atmospheric turbulence result in a spreading of the beam beyond that due to pure diffraction, random variations of the position of the beam centroid, and a random redistribution of the beam energy within a cross section of the beam leading to irradiance fluctuations. Those effects have far-reaching consequences on astronomical imaging, free space optics (FSO) communications, remote sensing, laser satellite communication, astronomical imaging, adaptive optics, target designation, hyperspectral LiDAR, and other applications that require the transmission of optical waves through the atmosphere. Throughout this thesis, we introduce a globally concept of turbulence, focusing in atmospheric turbulence.Diverse experiments have been carried out, for instance, the propagation of two parallel thin beams under geometrical optics condition for studying the parameters of optical turbulence, and besides, the same optical configuration was used to investigate the best sampling rate for optical turbulence. Furthermore, we have measured evapotranspiration by remote sensing, in which we have heeded the fluctuations of the refractive index through the intensities of the turbulence. Finally, experiments which involve a new beam are also developed, such as phase-flipped Gaussian beam. This beam shows an experimental reduction on its irradiance fluctuations induced by the turbulence, which means that it has a high performance in optical communications. The experimental reduction aforementioned is proved through the comparison with the theory developed.
Author: Michael W. Fitzmaurice
Publisher:
Published: 1971
Total Pages: 196
ISBN-13:
DOWNLOAD EBOOKThe pertinent theoretical background and the results of a group of experiments conducted over 0.4- and 1.17-km near-ground horizontal ranges are presented. (1) The log-amplitude variances for HeNe (0.633 μm) and CO2 (10.6 μm) laser beams were found to have a ratio of 26.8, which is in close agreement with the predictions of Rytov-based spherical-wave theory. (2) Published measurements of the saturation level of the log-amplitude variance are reviewed and several inconsistencies noted. (3) The spatial correlation function of irradiance field was measured and found to agree with theory. The degree of correlation between different frequency beams which had traversed the same optical path was also measured and compared to theory. The data exhibited an unacceptably large scatter and did not show the wavelength dependence. (4) The log-normal, Rayleigh, and Rice probability distributions are discussed in terms of their applicability to irradiance statistics. Relatively weak 10.6 μm irradiance fluctuations were found to be equally well described by the log-normal and Rice distributions; strong fluctuations obtained at 0.488 μm were clearly best described by the log-normal distribution.
Author: Arun K. Majumdar
Publisher:
Published: 2011
Total Pages: 248
ISBN-13: 9780819487728
DOWNLOAD EBOOKIncludes Proceedings Vol. 7821
Author: Hugo Weichel
Publisher: SPIE-International Society for Optical Engineering
Published: 1990
Total Pages: 118
ISBN-13:
DOWNLOAD EBOOKAuthor: Hamid Hemmati
Publisher:
Published: 2015
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKThis series offers access to the latest innovations in research and technology and are among the most cited references in patent literature.
Author: Arun K. Majumdar
Publisher:
Published: 2010
Total Pages: 318
ISBN-13: 9780819483102
DOWNLOAD EBOOKIncludes Proceedings Vol. 7821
Author: Nathan Blaunstein
Publisher:
Published: 2017-09-21
Total Pages: 0
ISBN-13: 9781138105201
DOWNLOAD EBOOKCover -- Half Tilte -- Title Page -- Copyright Page -- Contents -- Preface -- Editors -- Contributors -- Symbols and Abbreviations -- 1. Atmosphere Fundamentals -- 2. Basic Aspects of Optical Wave Propagation -- 3. Atmospheric Turbulence in the Anisotropic Boundary Layer -- 4. Nonlinear Propagation of Laser Radiation in the Atmosphere -- 5. Peculiarities of Propagation of Ultrashort Laser Pulses and Their Use in Atmospheric Sensing -- 6. Isoplanarity Problem in Vision Theory -- Index
Author: Heba Yuksel
Publisher:
Published: 2005
Total Pages:
ISBN-13:
DOWNLOAD EBOOKAuthor: Hamid Hemmati
Publisher:
Published: 2017
Total Pages:
ISBN-13: 9781510606340
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