Accession Number:

ADA535596

Title:

Reconstruction of Aerosol Properties from Forward-scattering Intensities

Descriptive Note:

Corporate Author:

ARMY RESEARCH LAB ADELPHI MD COMPUTATIONAL AND INFORMATION SCIENCES DIRECTORATE

Personal Author(s):

Report Date:

2011-01-01

Pagination or Media Count:

24.0

Abstract:

This work describes the design and application of an apparatus to image aerosol particles using digital holography in a flowthrough, contact-free manner. Particles in an aerosol stream are illuminated by a triggered, pulsed laser and the pattern produced by the interference of this light with that scattered by the particles is recorded by a digital camera. The recorded pattern constitutes a digital hologram from which an image of the particles is computationally reconstructed using a fast Fourier transform. This imaging is validated using a cluster of ragweed pollen particles. Examples involving mineral-dust aerosols demonstrate the techniques in situ imaging capability for complex-shaped particles over a size range of roughly 15-500 micrometer. The focusing-like character of the reconstruction process is demonstrated using a sodium chloride NaCl aerosol particle and is compared to a similar particle imaged with a conventional microscope.

Subject Categories:

  • Physical Chemistry
  • Holography
  • Photography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE