A REAL TIME FOURIER TRANSFORM SYNTHESIZER

Abstract

A study of the relationship between the interferogram F(x) obtained in Fourier spectroscopy and the corresponding spectral distribution E is made. It is found that the spectral distribution is the Fourier cosine transform of the interferogram. Various computational techniques for performing the required transformation are studied, and a real time Fourier transform synthesizer is described. It has been designed to be compatible with a lamellar grating Michelson interferometer, but could be used just as well with a well-compensated Michelson interferometer. The system used to obtain the point of zero path difference is described in detail. A novel approach is used to obtain the cosine functions required in the synthesis of the cosine transform. All the computations except the summation are done in analog form, while the summation is done digitally. The result of the computation, the spectral distribution, is available as soon as the interferogram is obtained. Errors in the technique are discussed and methods of compensating for them are enumerated.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1966
Accession Number
AD0653200

Entities

People

  • Joseph E. Hoffman Jr

Organizations

  • Utah State University

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Amplifiers
  • Bandwidth
  • Birds
  • Circuit Analysis
  • Electrical Engineering
  • Fourier Series
  • Frequency
  • Frequency Domain
  • Frequency Synthesizers
  • Generators
  • Michelson Interferometers
  • Refraction
  • Shape
  • Signal Generators
  • Spectroscopy
  • Waveforms

Fields of Study

  • Engineering
  • Physics

Readers

  • Approximation Theory.
  • Optical Physics and Photonics.