Relationships between Radiative Properties and Mass Content of Phosphoric Acid, HC, Petroleum Oil, and Sulfuric Acid Military Smokes.
Abstract
The tactical effectiveness of military electro-optical devices such as the forward looking infrared or high energy laser (HEL) systems requires a knowledge of the extinction (absorption and scattering) by the intervening atmosphere. In the case of intentionally produced obscurants such as smokes, a quantitative assessment of these effects generally requires knowledge of the size distribution and concentration of the particles. A relation between the radiative properties of smoke particles and their mass content, even if it is an approximate one, would reduce the complexity of this assessment. One would then only need to know the spacial distribution of the mass content of the smoke particles rather than the details of their particle size distributions and number concentrations. In this report, a linear relation, independent of particle size distribution, between aerosol volume extinction coefficient and mass content is derived and applied to several military smokes: solutions of orthophosphoric acid in water, zinc chloride in water (HC smoke), diesel fuel, fog oil, and sulfuric acid smoke. Comparison of the theoretical extinction-mass relation with infrared (IR) transmission measurements of Milham (1976), Milham et al (1977), and Carlon et al (1977) shows good agreement (generally within 30 percent) between theory and measurement for the highly absorbing phosphoric acid and sulfuric acid smokes , but only fair-to-poor agreement (up to factors of 2.5 to 10 differences) for weakly absorbing HC and fog oil smokes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1980
- Accession Number
- ADA084941
Entities
People
- R. G. Pinnick
- S. G. Jennings
Organizations
- Atmospheric Sciences Laboratory