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Full-Text Articles in Engineering
Statistical Fading Of A Plane Optical Wave In Atmospheric Turbulence, John F. O'Hara
Statistical Fading Of A Plane Optical Wave In Atmospheric Turbulence, John F. O'Hara
Retrospective Theses and Dissertations
A formula for the average fade time of the intensity of a plane optical wave traveling through atmospheric turbulence is developed. The model employed involves isotropic, homogeneous statistics using a lognormal distribution for the channel. The analysis is based on the fact that the logarithm of the irradiance is normally distributed and uses the work of S. O. Rice who developed such an expression for a zero mean, Gaussian process. The analysis employs the covariance function and the Taylor frozen turbulence hypothesis which results in an expression for the autocorrelation function.
Fade Time Statistics Of Laser Light Propagating Through Turbulent Atmosphere, Madjid A. Belkerdid
Fade Time Statistics Of Laser Light Propagating Through Turbulent Atmosphere, Madjid A. Belkerdid
Retrospective Theses and Dissertations
The average fade time of the fluctuations in the intensity of laser light propagation in the atmosphere is analyzed. Experimental results show that the average fade time for a propagation distance of 208 meters, in the weak turbulence regime, is well described by formulas developed from a Log-Normal distribution. A circuit that calculates real time statistics of fade time is designed, then validated using a sine wave input whose fade time statistics are predetermined. The experimental signal is then tested for stationarity, and the average fade time is measured. A curve fitting is then performed for the experimental data and …
The Silicon Solar Cell As An Optical Detector, Stephen O. Saltsman
The Silicon Solar Cell As An Optical Detector, Stephen O. Saltsman
Retrospective Theses and Dissertations
The optical detector characteristics of a silicon solar cell are examined. A general equivalent circuit model is developed and typical parameter values are determined. A comparison is made between the photovoltaic and short circuit operating modes and the short circuit mode is shown to be preferable in terms of linearity, extended frequency response, and temperature stability. A method is developed to determine the noise characteristics of the amplifier-detector system used in the short circuit mode. The silicon solar cell is shown to be an economical alternative to standard photodiodes in low to medium data rate systems.
Simulation Of A Fiber-Optical Communication System, Patricia Kay Scheffel
Simulation Of A Fiber-Optical Communication System, Patricia Kay Scheffel
Retrospective Theses and Dissertations
The feasibility of analyzing an optical communication system using standard electronic circuit analysis programs such as SCEPTRE and ASTAP is demonstrated in this thesis. The transmitter (laser and modulator) and receiver (detector and amplifier) are modelled using equivalent circuits for the various components. The transmission medium (optical fiber) is modelled using an impulse response function. Two fibers are investigated--a step-index fiber and a square-law (parabolic index) fiber.
A Computer Simulation Of A Weapons Fire Simulator Modeled By Sceptre As An Optical Communication Channel, John James Cormack
A Computer Simulation Of A Weapons Fire Simulator Modeled By Sceptre As An Optical Communication Channel, John James Cormack
Retrospective Theses and Dissertations
This paper presents a method of simulating various noise sources in a Weapons Fire Simulator System which has been modeled as an Optical Communication Channel. This Weapons Fire Simulator System is composed of laser transmitters mounted on weapons that fire blank cartridges, and laser receivers mounted on targets. The laser transmitter sends out 'kill' beam pulses to the target whenever blank cartridges are fired. Detection of these pulses at the target signifies a 'hit'. The entire system along with the optical communication channel is simulated in a general purpose computer program called SCEPTRE. This analysis package is an efficient means …