Accession Number:

ADA622740

Title:

Imaging Through Random Discrete-Scatterer Dispersive Media

Descriptive Note:

Final rept. 15 Apr 2012-14 Apr 2015

Corporate Author:

MONOPOLE RESEARCH THOUSAND OAKS CA

Report Date:

2015-08-27

Pagination or Media Count:

39.0

Abstract:

The objective of the effort was to develop a methodology which would allow enhanced signal transmission, high resolution range imaging andor target detection through optically obscuring, dilute, discrete-scatterer media such as clouds, fog, dust and other aerosols. A Properties of chirped-train waveforms such as their multi-band power spectra and the resulting point spread and ambiguity functions were analyzed. Advantages of the utilization of chirped trains in multi-spectralimaging i.e., imaging based on frequency sub-bands of the chirped train signal allowing extraction of frequency dependent information with improved signal-to-noise ratio was observed. B Propagation of short infraredoptical pulses in dilute random media consisting of large, compared to the wavelength, scatterers was analyzed. A rigorous approach based on analytic complex-contour integration of numerically determined cut and pole singularities of the radiative transport equation solution in the Fourier space was developed. It was found that the intensity of a propagating pulse, in addition to the coherent ballistic contribution and a long late-time diffusive tail, also exhibits a sharply rising early-time component that i can be attributed to the small-angle diffractive part of the scattering cross-section on medium particles, ii is attenuated proportionally to the nondiffractive rather than total cross-section, and iii can be extracted by high-pass filtering of the received pulse.

Subject Categories:

  • Atmospheric Physics
  • Electricity and Magnetism
  • Optics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE