PNNL-13501 - Pacific Northwest National Laboratory

Single Channel Signal
0.0025
0.0020
0.0015
0.0010
0.0005
Single Channel Reflectance Spectra vs. Wavenumber (cm -1 )
Single channel spectrum: quartz sand
200 to 290 µm grain size, dry
Single channel spectrum: quartz sand
200 to 290 µm grain size,
coated with dimethyl methylphosphonate
Reflectance spectrum is the ratio of coated
sand to dry sand. Reflectance angle is 63°.
0.0000
4000 3600 3200 2800 2400 2000 1600
Wavenumbers (cm
1200 800 400
-1 )
Figure 3. Infrared spectra of dimethyl methylphosphonate
on quartz sand
Single Channel Signal
Single Channel Signal
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
4000 3600 3200 2800 2400 2000
Wavenumbers (cm
1600 1200 800 400
-1 Comparison of Single Channel Reflectance Signal for Mirror, Sand, and Quartz Crystal
(reflectance angle ca. 45°)
mirror reflectance
quartz slab reflectance
)
0.0020
0.0015
0.0010
0.0005
Ottawa quartz sand (540-840 µm particle size) reflectance
0.0000
4000 3600 3200 2800 2400 2000 1600
Wavenumbers (cm
1200 800 400
-1 )
Figure 4. Comparison of reflectance signal strength for a
flat mirror, a quartz slab, and quartz sand
We found that for the same compound, dimethyl
methylphosphonate for example, its evaporation rate off
of metal surfaces is extremely slow compared to that off
of quartz crystal, and is different than that off the quartz
3.0
2.5
2.0
1.5
1.0
0.5
Ratio Coated Spec./Dry Spec.
sand. Research into this would provide invaluable
information to modelers calculating the accumulation of
effluent compounds on surfaces surrounding proliferation
sites.
Summary and Conclusions
We established a spectroscopic facility for recording
reflectance spectra of chemical compounds coated onto
terrestrial surfaces. Prominent spectral feature changes
take place when these surfaces are coated. The continued
research will provide a database of compounds and
surfaces that should prove valuable to the intelligence
community for evaluating possible weapons of mass
destruction proliferation sites.
References
Asrar G. 1989. Theory and Applications of Optical
Remote Sensing. Chapter 12, John Wiley & Sons, New
York.
Barettino EL-PD, C Anton-Pacheco, G Ortiz, JC Arranz,
JC Gumiel, B Martinez-Pledel, M Aparicio, and
O Montouto. 1999. “The Extent of the Aznalcollar
Pyritic Sludge Spill and its Effects on Soils.” Sci. Tot.
Environ. 242:57-88.
Brodskii ES, SA Savchuk. 1998. “Determination of
Petroleum Products in the Environment.” J. Anal. Chem.
53:1070-1082.
Mikati GOF. 1997. Temporal Analysis of Multispectral
Video/Satellite Imagery for the Detection and Monitoring
of Salinity on Agricultural Lands. Dissertation, Utah
State University, UMI order no. DA9822024.
Wolfe WL, GJ Zissis, eds.. 1985. The Infrared
Handbook. pp 19-10 – 19-17. ERIM, Ann Arbor,
Michigan.
Sensors and Electronics 403