RTO-TR-SET-098 - FTP Directory Listing - Nato

1.0 INTRODUCTION
LASER BASED STAND-OFF DETECTION
OF BIOLOGICAL AGENTS
Biological weapons have become an increasingly important potential threat in today’s military and civilian
arenas. They are relatively inexpensive to produce and can yield a significant impact as a terrorist weapon.
Early warning of a biological attack is essential to establish a timely defence and to sustain operational tempo
and freedom of action. In addition, the mapping of a biological attack is needed to obtain intelligence on
affected areas. For these reasons the need to develop methods to remotely detect and discriminate biological
aerosols from background aerosols, and ultimately, to discriminate biological warfare agents from naturally
occurring aerosols, is paramount.
Figure 1: Stand-Off Detection for Early Warning of a Biological Attack.
Discriminating clouds that contain biological warfare agents from background aerosols with stand-off detection
is extremely challenging because the distinction between innocuous, ambient bacteria and other biota and
virulent microbes amounts to subtle differences in the molecular make-up. Since these subtle changes involve
such a small percentage of the molecules, only a slight effect on their optical signatures is observed, making a
high confidence detection and discrimination difficult. In addition, variations in growth media and contaminants
associated with the processing of bio-warfare agents can affect their optical signatures, further exacerbating the
task of analyzing and successfully discriminating the agent.
In order to address these fundamental challenges several stand-off technologies covering a broad region of the
electromagnetic spectrum are being investigated under RTG-055. These technologies include spectrally
resolved Ultraviolet Laser Induced Fluorescence (UV-LIF) at several different excitation wavelengths,
Infrared Depolarization, and Long-Wave Infrared (LWIR) Differential Scattering (DISC). Each of these
technologies offers its own strengths and challenges and all of them have demonstrated the ability to detect
and discriminate biological aerosol clouds to varying degrees. Annex A documents the brief review conducted
at the start of this TG of the lasers that were available and suitable for use in these systems. Annex B
documents a portion of the market survey conducted to evaluate the scientific validity of the technology for
short range stand-off biological detection. Annex C contains the final presentation of RTG-055 given to the
SET Business Panel in May 2008.
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