Undisturbed soil generally consists of larger silica particles where the smaller particles have been removed from the surface by weathering, i.e., rain. Large silica particles exhibit a significant reflectance in the 7 – 12 μm spectral region called the Reststrahlen band. It has been demonstrated that the Reststrahlen band intensity is proportional to the particle size distribution of silica in the soil; as the proportion of small to large silica particles increases the Reststrahlen band also decreases in intensity. When soil is disturbed, for example when an object is buried, the distribution of silica particles is changed such that the “new” surface consists of a greater proportion of small to large silica particles. The increased number of small silica particles decreases the intensity of the Reststrahlen band therefore enabling detection of buried objects by imaging in the 7 – 12 μm spectral range. There is a second reflectance band in the 17 – 25 μm spectral region which has not been used for detection of buried objects. We investigate the behavior of this second Reststrahlen band for disturbed earth and evaluate its use for enhanced detection of buried objects when combined with the first Reststrahlen band.

Date Published: 29 May 2014
PDF: 6 pages
Proc. SPIE 9072, Detection and Sensing of Mines, Explosive Objects, and Obscured Targets XIX, 90721E (29 May 2014); doi: 10.1117/12.2058869

Published in SPIE Proceedings Vol. 9072:
Detection and Sensing of Mines, Explosive Objects, and Obscured Targets XIX
Steven S. Bishop; Jason C. Isaacs, Editor(s)