Standoff sensing of bioaerosols using intensified range-gated spectral analysis of laser-induced fluorescence

• Published in: IEEE transactions on geoscience and remote sensing Vol. 42; no. 4; pp. 865 - 874
• Main Authors: Simard, J.-R., Roy, G., Mathieu, P., Larochelle, V., McFee, J., Ho, J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-04-2004; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aerosols; Applied geophysics; Bacteria; Biological materials; Composite materials; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fluorescence; Internal geophysics; Laser radar; Light scattering; Optical materials; Particle scattering; Raman scattering; Spectral analysis; Canada; models; detection; laser methods; density; aerosols; nitrogen; spectral analysis; air; Raman spectroscopy; North America; laser-induced fluorescence (LIF); spatial distribution; spectral signature; Bioaerosol; fluorescence; spectroscopy; light detection and ranging (LIDAR); intensified charge-coupled device (ICCD); Raman; programs; calibration
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2003.823285

In atmospheric sensing, one application that has demonstrated several impressive successes over the last two decades is the light detection and ranging (LIDAR). Elastic LIDAR has shown an important capability in providing aerosol density and spatial distribution from a standoff position. However, it provides limited information on the material composition of the aerosol component. On the other hand, inelastic LIDARs (including laser-induced fluorescence and Raman LIDARs) measure the spectrally distributed returned signal that may contain important clues about the nature of the scatterers. In order to investigate the capability of these LIDARs in characterizing bioaerosols from a standoff position, Defence Research & Development Canada initiated a three-year program in spring 1999, named SINBAHD (Standoff Integrated Bioaerosol Active Hyperspectral Detection). The aim of the program was to investigate the sensitivity and discrimination capabilities of an inelastic LIDAR based on the intensified range-gated spectral detection of laser-induced fluorescence. An exploratory prototype based on this technique has shown sensitivity of a few living bioaerosol particles per liter of air for a range of 1.4 km at night. Furthermore, based on spectral signatures measured during open-air releases, good discrimination capabilities were obtained between Bacillius subtilis var globiggi (BG) and Erwinia herbicola (EH). These results agree well with a performance model using Raman returns from atmospheric nitrogen as a calibration tool.