Simulants: Nonpathogenic or nontoxic warfare agent surrogates that provide useful evaluative information on the performance of a biological detection system and can sometimes be directly correlated with the biological warfare agent being simulated.

Standoff detection: Detection at a distance away from the aerosol/plume or detector system (Joint Program Executive Office for Chemical and Biological Defense 2004).

Surrogate: an organism or material that serves as a substitute for biological warfare agent.