Material Identification Algorithm

Abstract

We developed numerical techniques for simulating radar returns from large realistic scenes composed of uneven ground, trees, and reflecting objects. The simulation includes effects of ionospheric dispersion on the radar pulses. We developed an integral-equation code and performed numerical simulation of radiation for small-loop large-current antennas, with loops radiating in open space or partly shielded by enclosures of various material properties. The code implements regularization methods for handling of subwavelength electromagnetic radiation problems in the presence of materials. We developed a fast integral-equation based solver for simulating propagation of thermo-acoustic waves induced by short microwave pulses in biological media, in particular in the human head. The code implements a matrix compression based on fast Fourier transforms (FFTs), as well as a rescaling technique which allows us to treat problems with large contrasts of material parameters. We analyzed propagation of infra-red (IR) radiation through dilute and dense media composed of discrete scatterers. In application to propagation of short IR pulses through atmospheric clouds we established conditions under which the waves may experience reduced attenuation. To allow simulation of propagation in dense media, we developed a fast integral-equation solver for a two-dimensionally periodic system modeling a laterally infinite slab of the medium.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2007
Accession Number
ADA478950

Entities

People

  • Elizabeth Bleszynski
  • Marek Bleszynski
  • Thomas Jaroszewicz

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Acoustic Waves
  • Acoustics
  • Algorithms
  • Attenuation
  • Contrast
  • Electromagnetic Fields
  • Electromagnetic Pulses
  • Electromagnetic Scattering
  • Electromagnetic Wave Propagation
  • Equations
  • Integral Equations
  • Integrals
  • Materials
  • Metamaterial Absorbers
  • Scattering
  • Simulations
  • Waves

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Wave Propagation and Nonlinear Chaotic Dynamics.

Technology Areas

  • Space