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Full-Text Articles in Signal Processing
A Diffraction-Based Model Of Anisoplanatism Effects In Adaptive Optic Systems, Steven E. Troxel
A Diffraction-Based Model Of Anisoplanatism Effects In Adaptive Optic Systems, Steven E. Troxel
Theses and Dissertations
This dissertation presents a new model for computing the angle dependent performance measures of an adaptive-optics system. By incorporating diffraction caused by the index-of-refraction variations of the atmosphere, the phase and amplitude fluctuations of the propagating wave are computed. New theory is presented, that uses the diffraction-based propagation model to yield optical transfer function (OTF) expressions that are more accurate as compared to current theory that neglects diffraction. An evaluation method for calculating the OTF is presented that utilizes a layered atmospheric model and normalized OTF expressions. The diffraction model is also used to present the first OTF signal-to-noise ratio …
Spatio-Temporal Pattern Recognition Using Hidden Markov Models, Kenneth H. Fielding
Spatio-Temporal Pattern Recognition Using Hidden Markov Models, Kenneth H. Fielding
Theses and Dissertations
A new spatio-temporal method for identifying 3D objects found in 2D image sequences is presented. The Hidden Markov Model technique is used as a spatio-temporal classification algorithm to identify 3D objects by the temporal changes in observed shape features. A new information theoretic argument is developed that proves identifying objects based on image sequences can lead to higher classification accuracies than single look methods. A new distance measure is proposed that analyzes the performance of Hidden Markov Models in a multi-class pattern recognition problem. A three class problem identifying moving light display objects provides experimental verification of the sequence processing …
Feasibility Analysis For Predicting A Kinetic Kill Zone For Aircraft Homing Missile Defense, Mark E. Ennis
Feasibility Analysis For Predicting A Kinetic Kill Zone For Aircraft Homing Missile Defense, Mark E. Ennis
Theses and Dissertations
An extended Kalman filter is used to predict a kinetic kill zone for use in aircraft self defense versus homing missiles. The analysis is limited to an in-the-plane analysis and focuses on finding the model parameters which have the largest impact on the predicted kill zone. No attempt is made to optimize the design of the filter model itself. The analysis computes the kill zone relative to an assumed aircraft trajectory using strictly filter computed statistics. No Monte-Carlo simulations are used throughout the thesis. The filter assumed to be on the evading aircraft, uses an onboard laser radar (ladar) to …