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Computational fluid dynamics modeling of atmospheric flow applied to wind energy research /Russell, Alan, January 2009 (has links)
Thesis (M.S.)--Boise State University, 2009. / Includes abstract. Includes bibliographical references (leaves 69-71).
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Wind and turbulence structure in the boundary layer over the Antarctic PlateauDabberdt, Walter F. January 1969 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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Observations of convective scale turbulence over the tropical oceanBerman, Elizabeth Ashton. January 1975 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1974. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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THE EFFECT OF TURBULENT MOTION ON TROPOSPHERIC SCATTER PROPAGATION OF RADIO WAVESLatorre, Victor Robert, 1931- January 1960 (has links)
No description available.
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Position-sensitive devices and sensor systems for optical tracking and displacement sensing applicationsMäkynen, A. (Anssi) 11 October 2000 (has links)
Abstract
This thesis describes position-sensitive devices (PSDs) and optical sensor systems suitable for industrial tracking and displacement sensing
applications. The main application areas of the proposed sensors include automatic pointing of a rangefinder beam and measuring the lateral
displacement of an object.
A conventional tracking sensor is composed of a laser illuminator, a misfocused quadrant detector (QD) receiver and a corner cube retroreflector
(CCR) attached to the target. The angular displacement of a target from the receiver optical axis is detected by illuminating the target and
determining the direction of the reflection using the QD receiver. The main contribution of the thesis is related to the modifications proposed
for this conventional construction in order to make its performance sufficient for industrial applications that require a few millimetre to
submillimetre accuracy. The work includes sensor optical construction modifications and the designing of new types of PSDs.
The conventional QD-based sensor, although electrically very sensitive, is not considered optimal for industrial applications since its precision
is severely hampered by atmospheric turbulence due to the misfocusing needed for its operation. Replacing the CCR with a sheet reflector is found
to improve the precision of the conventional sensor construction in outdoor beam pointing applications, and is estimated to allow subcentimetre
precision over distances of up to 100 m under most operating conditions. Submillimetre accuracy is achievable in close-range beam pointing
applications using a small piece of sheet reflector, coaxial illumination and a focused QD receiver. Polarisation filtering is found to be
effective in eliminating the main error contributor in close-range applications, which is low reflector background contrast, especially in cases
when a sheet reflector has a specularly reflecting background.
The tracking sensor construction is also proposed for measuring the aiming trajectory of a firearm in an outdoor environment. This time an order
of magnitude improvement in precision is achieved by replacing the QD with a focused lateral effect photodiode (LEP). Use of this construction in
cases of intermediate atmospheric turbulence allows a precision better than 1 cm to be achieved up to a distance of 300 m. A method based on
averaging the positions of multiple reflectors is also proposed in order to improve the precision in turbulence-limited cases.
Finally, various types of custom-designed PSDs utilising a photodetector array structure are presented for long-range displacement sensing
applications. The goal was to be able to replace the noisy LEP with a low-noise PSD without compromising the low turbulence sensitivity achievable
with the LEP. An order of magnitude improvement in incremental sensitivity is achievable with the proposed array PSDs.
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Optical vortex detection and strongly scintillated beam correction using Vortex Dipole AnnihilationChen, Mingzhou 06 May 2009 (has links)
Please read the abstract on page i of this thesis / Thesis (PhD)--University of Pretoria, 2009. / Electrical, Electronic and Computer Engineering / unrestricted
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The relationships between several parameters which may be used to represent atmospheric vorticesUnknown Date (has links)
"The study was restricted to cyclones which appeared over Europe for at least two consecutive days during 1950"--Page v. The statistical relationships between five parameters which may be used to represent an atmospheric vortex are studied. These parameters are: the central height, ?h, the space change of height, ?h, a size factor, D, the mean gradient, h, and the "gradient-area index", I. The primary purpose of the study is to determine the relationship between the central height and each of the other parameters. The study was restricted to cyclones which appeared over Europe for at least two consecutive days during 1950. All measurements were made on the 500-mb chart. Each parameter was evaluated for 263 cyclones and the 24-hr change of each parameter was computed for 208 cyclones. The methods used to evaluate each parameter are discussed. For each pair of parameters, linear correlation coefficients were computed from grouped data. / "A Paper." / Typescript. / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Science." / Advisor: Thomas A. Gleeson, Professor Directing Paper. / Author's name handwritten on cover: Robert B. DesJardins. / Includes bibliographical references.
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Weakly inhomogeneous turbulence theory with applications to geophysical flowsHo, Lin, Ph. D. Massachusetts Institute of Technology January 1982 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1982. / Microfiche copy available in Archives and Science. / Supervised by Edward N. Lorenz. / Includes bibliographical references (leaves 141-145). / by Lin Ho. / Ph.D.
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Intermittent behavior in numerical solutions to a nonlinear system of equationsPollack, Jon Alan January 1979 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Microfiche copy available in Archives and Science. / Bibliography : leaves 71-72. / by Jon Alan Pollack. / M.S.
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A higher order closure turbulence model of the planetary boundary layerScire, Joseph Stephen January 1979 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Microfiche copy available in Archives and Science. / Bibliography : leaves 151-154. / by Joseph Stephen Scire. / M.S.
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