The Spectrum of Electromagnetic Scatter from an Ensemble of Bodies with Angular Periodicity, as a Model for Jet Engine Modulation

Abstract

A rotating ensemble of bodies of arbitrary shape with angular periodicity scatters an electromagnetic wave to produce a spectrum of frequency components characteristic of the structure and its rotation. The spectrum and its properties are predicted through electromagnetic field theory. The theory has been developed such as to exploit the angular periodicity and therefore reduce the computational load by a large factor. A consequence of the approach is that the spectrum is found directly. Many of the predictions have been confirmed by direct computation of the scattered field for a series of rotational positions to simulate a time series, followed by a discrete Fourier transforming to produce the spectrum.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2001
Accession Number
ADA392294

Entities

People

  • John Cashman

Organizations

  • Defence Science and Technology Group

Tags

Communities of Interest

  • Air Platforms
  • C4I
  • Space

DTIC Thesaurus Topics

  • Australia
  • Coordinate Systems
  • Current Density
  • Department Of Defense
  • Diffraction
  • Doppler Effect
  • Electric Fields
  • Electromagnetic Fields
  • Frequency
  • Integral Equations
  • Jet Engines
  • Periodic Variations
  • Plane Waves
  • Radar
  • Spectra
  • Spectral Lines
  • Surveillance

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Plasma Physics / Magnetohydrodynamics
  • Radio communications and signal processing.