Extracting Scattering Observables From Digital Holograms: Application to Aerosol Particle Characterization
Abstract
The objective of this project is to expand the recent efforts in holography of aerosol particles to extract specific scattering parameters. The major objectives of this work are divided into the four projec1 phases. The overarching goal is to build the first experimental survey of qerosol-particle morphology simultaneous with scattering observables. The work will be undertaken as follows: I. The first phase of work will demonstrate that the single-particle extinction can be extracted from a measured digital contrast hologram. Image-resolution improvements will be implemented using a large-format 6000x6000 CCD sensor and a 351 nm Q-switched Nd:YLF laser through a DURIP grant. The work will begin with spherical PSL calibration-particles where the extracted extinction can be compared to Mie theory. Once this validation step is completed, the study will be extended to particles of increasingly more complex morphology. II. This effort will begin with PSL calibration particles to enable direct comparison of the patterns to Mic theory. It also will begin with large particles > 10 µm in size. Once this validation is perfom1ed, smaller particles will be investigated to establish the practical limitations of the pattern extraction. The procedure will continue with complex shaped particles results will be compared to studies in the literature where, e.g., forward-scattering measurements have been made to size such particles. III. A polarimetric component will be incorporated into the system, and the polarimetric measurements will be made. As with the previous steps, the study will begin with spheres and continue with complex particles. IV. The final phase of this work will involve a summer site-visit to A RL to work with staff scientists in the Atmospheric Sensing Branch of the Battlefield Environment Division in the Computational and lnfonnation Sciences Directorate, in particular Ors. Yong-Le Pan and Steven Hill. The objective will be to integrate the holography-based concepts with ARL methods to establish how well the former can enhance these characterization efforts.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510549
Entities
People
- Matthew J. Berg
Organizations
- Army Contracting Command
- Mississippi State University
- United States Army