Gap Detection with Electromagnetic Terahertz Signals

Abstract

We apply an inverse problem formulation to determine characteristics of a defect from a perturbed electromagnetic interrogating signal. A defect (gap) inside of a dielectric material causes a disruption, via reflections and refractions at the material interfaces, of the windowed interrogating signal. We model the electromagnetic waves inside the material with Maxwell's equations. This leads to a non-standard, nonlinear optimization problem for the dimensions and location of the defect. Using simulations as forward solves, we employ a Newton-based, iterative optimization scheme to a novel modified least-squares objective function. Numerical results are given in tables and plots, standard errors are calculated, and computational issues are addressed.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2004
Accession Number
ADA444275

Entities

People

  • H. Thomas Banks
  • Nathan L. Gibson
  • William P. Winfree

Organizations

  • North Carolina State University

Tags

Communities of Interest

  • Advanced Electronics
  • Sensors

DTIC Thesaurus Topics

  • Algorithms
  • Boundaries
  • Computational Science
  • Computations
  • Detection
  • Dielectrics
  • Electric Fields
  • Electromagnetic Fields
  • Equations
  • Finite Element Analysis
  • Inverse Problems
  • Low Resolution
  • Magnetic Fields
  • Materials
  • Simulations
  • Simulators
  • Travel Time

Fields of Study

  • Physics

Readers

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