A method and device for remotely analyzing an agent dispersed in the atmosphere is disclosed in which a body is dispensed into a volumetric region of the atmosphere overlapping the region containing the agent. The body is tailored to induce changes in an electromagnetic response of the volumetric region including the agent due to body the reactive probe and the agent. By sensing electromagnetic radiation from the region, information may be gained concerning the agent based upon the new electromagnetic response of the volumetric region induced by the reactions. Since a probe is used, source need not be known, and the electromagnetic signature may be tailored to atmospheric and device limitations.