Isn't this almost exactly what Loch Harris and now CDEx claim are potential applications? (bold at bottom)
Multispectral Ultraviolet Fluorescence Lidar System Identifies
Chemical Mixtures in Field Tests
by P. J. Hargis, Jr., G. C. Tisone, T. D. Raymond, J. G. Taylor, J. S. Wagner, I. S. Shokair,
R. D. Mead, J. D. Daniels, T. J. Sobering, M. S. Johnson, M. W. Trahan,
B. F. Clark, C. Wakefiled-Reyes, and F. R. Franklin
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Motivation
Highly sensitive ultraviolet (UV) measurements are generally thought to be of limited use in lidar systems designed to detect chemical species in the atmosphere. Recent work at Sandia National Laboratories has changed this perception and led to the development of a new multispectral UV fluorescence lidar system designed for remote chemical analysis. Briefly, a broadly tunable UV laser is used to transmit multiple laser wavelengths, some of which are selectively absorbed and subsequently excite fluorescence in specific chemical species. The resulting fluorescence spectra at each excitation wavelength are compared to a database of fluorescence spectra from individual species to determine species concentrations. The com-parison is carried out using a unique multivariate analysis algorithm developed at Sandia to determine species concentrations from multi-spectral UV fluorescence measurements.
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Accomplishment
Sandia’s multispectral UV fluorescence lidar system was tested in July 1995 at the Nevada Test Site. Measurements were made on vapor plumes consisting of mixtures of benzene, m-xylene, p-xylene, and toluene ranging in concentration from 1 to 500 ppm. All measurements were made at a standoff distance of 0.5 km. Atmospheric attenuation coefficients derived from elastic backscatter measurements were used in the multivariate analysis algorithm to correct measured fluorescence spectra for distortions due to transmission of the fluorescence radiation through the atmosphere. The analysis algorithm was then used to determine species concentrations and time-dependent concentration profiles. Almost 95% accuracy was achieved in identifying species in chemical plumes containing up to four species. Fluorescence detection limits for individual species ranged from about 5 to 10 ppm-m for all measured species. Highlights of the field test results include the first multivariate analysis of multispectral absorption and fluorescence data and the capability of UV fluorescence lidar measurements to map species concentrations in chemical plumes.
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Significance
Data obtained at the July 1995 field test demonstrates the potential of multispectral UV fluorescence measurements to detect nuclear, chemical, and biological proliferation activities. Other areas of national importance that benefit from the new technology are counterterrorism, drug interdiction, environmental monitoring, and global climate change.
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