Application of a natural-resonance based feature extraction technique to small-scale aircraft wires for electromagnetic target classification

Download

index.pdf

Date

2004

Author

Ersoy, Mehmet Okan

Metadata

Show full item record

Item Usage Stats

213
views

69
downloads

The problem studied in this thesis, is the classification of the small-scale aircraft targets by using a natural resonance based electromagnetic feature extraction technique. The aircraft targets are modeled by perfectly conducting, thin wire structures. The electromagnetic back-scattered data used in the classification process, are numerically generated for five aircraft models. A contemporary signal processing tool, the Wigner-Ville distribution is employed in this study in addition to using the principal components analysis technique to extract target features mainly from late-time target responses. The Wigner-Ville distribution (WD) is applied to the electromagnetic back-scattered responses from different aspects. Then, feature vectors are extracted from suitably chosen late-time portions of the WD outputs, which include natural resonance related v information, for every target and aspect to decrease aspect dependency. The database of the classifier is constructed by the feature vectors extracted at only a few reference aspects. Principal components analysis is also used to fuse the feature vectors and/or late-time aircraft responses extracted from reference aspects of a given target into a single characteristic feature vector of that target to further reduce aspect dependency. Consequently, an almost aspect independent classifier is designed for small-scale aircraft targets reaching high correct classification rate.

Subject Keywords

Applications of Electric Power.

URI

http://etd.lib.metu.edu.tr/upload/3/12605522/index.pdf
https://hdl.handle.net/11511/14592

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Series active filter design, control, and implementation with a novel load voltage harmonic extraction method Şentürk, Osman Selçuk; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2007) Series Active Filters (SAF) are designed for harmonic isolation and load voltage regulation of single-phase and three-phase voltage harmonic source type nonlinear loads. The novel Absolute Value Method (AVM) for load voltage harmonic extraction is proposed and applied in the control algorithm of SAF. The SAF compensated systems are represented by simplified linear models such that SAF controller gains can be easily determined. Harmonic isolation and load voltage regulation performances of 2.5 kW single-phas...
Design and implementation of an ultracapacitor test Eroğlu, Hasan Hüseyin; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2010) In this thesis, a test system is designed and implemented in order to evaluate the basic electrical performance and determine the parameters of ultracapacitors (UC). The implemented UC test system is based on power electronics converters and it is capable of charging and discharging the UC under test with predetermined current profiles. The charging operation is provided by a configuration involving the AC utility grid, a step-down transformer, a diode bridge, and a DC bus filter capacitor followed by a ste...
Optimizing transient and filtering performance of a C-type 2nd harmonic power filter by the use of solid-state switches Gerçek, Cem Özgür; Ertaş, Arif; Department of Electrical and Electronics Engineering (2007) In this research work, the performance of a C-type, 2nd harmonic power filter is optimized by the use of a thyristor switched damping resistor. In the design of conventional C-type, 2nd harmonic filters; the resistance of permanently connected damping resistor is to be optimized for minimization of voltage stresses on filter elements arising from switchings in transient state and for maximization of filtering effectiveness in the steady-state. Transformer inrush current during energization of power transfor...
Design and implementation of advanced pulse width modulation techniques and passive filters for voltage source inverter driven three-phase ac motors Nebi, Onur Çetin; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2010) Advanced pulse width modulation (PWM) techniques such as space vector PWM, active zero state PWM, discontinuous PWM, and near state PWM methods are used in three-phase AC motor drives for the purpose of obtaining low PWM current ripple, wide voltage linearity range, and reduced common mode voltage (CMV). In some applications, a filter is inserted between the inverter and the motor for the purpose of reducing the stresses in the motor. The motor current PWM ripple components, terminal voltage overshoots, sha...
Recognition of human face expressions Ener, Emrah; Severcan, Mete; Department of Electrical and Electronics Engineering (2006) In this study a fully automatic and scale invariant feature extractor which does not require manual initialization or special equipment is proposed. Face location and size is extracted using skin segmentation and ellipse fitting. Extracted face region is scaled to a predefined size, later upper and lower facial templates are used for feature extraction. Template localization and template parameter calculations are carried out using Principal Component Analysis. Changes in facial feature coordinates between ...

Citation Formats

M. O. Ersoy, “Application of a natural-resonance based feature extraction technique to small-scale aircraft wires for electromagnetic target classification,” M.S. - Master of Science, Middle East Technical University, 2004.