Technologies for standoff detection of liquid warfare agents

The topic of this report is a review of technologies that can be used for standoff detection of chemical warfare agents in the liquid phase, with the aim to point out technologies that could be topic of a further study. Required sensitivity for the technology to be operationally interesting is estimated both in view of exposure limits and existing capacities. An attempt is made to evaluate the potential sensitivity, standoff distance and special features of the different technologies. It is found that several technologies that use active illumination of the target are likely required to obtain sufficient sensitivity to be of interest in a further study. For long range standoff detection (>10 m) technologies involving short-pulse (femtosecond) lasers are most interesting, but infrared spectroscopy with either wavelength scanning lasers or Fouriertransform spectroscopic systems should also be considered. For short range (~1 meter) detection, several other potential technologies are also identified that could be a topic for a further study. A few short range technologies also have the capacity to detect subsurface contamination. Two of the promising techniques that could easily be started at FFI are pointed out. These are particularly interesting because the Institute both have high level competence in the field as well as most of the expensive instruments required to initiate an investigation, and include wavelength scanning with an infrared laser and Fourier-transform spectroscopy with active illumination. The final choice of technologies for a further study would, however, depend on the intended mode of operation as defined by the user. This has not been a topic of this work.