Abstract: A system having an optical remote sensor where sensing can be achieved from distance, and therefore without necessarily making contact with the threat chemical, with one or more in-situ sensors where sampling of air is required, and where at least one sensor is cross-reactive. Aspects of some of the various systems capable of achieving, but not limited to thereto, the following advantages: (a) by the optical sensor: long range advanced warning, rapid large volume analysis, fast response continuous monitoring for protection against bursts, safety to the operator, (b) by the in-situ sensor: high sensitivity, (c) by the combination of sensors, high specificity, better avoidance of interferences by chemicals and (d) by the inclusion of cross reactive characteristics, the ability to learn response to new chemicals.

Abstract: A method and a low-cost, robust and simple system for remote sensing and analyzing spectral properties of targets as a means to detect and identify them is introduced. The system can be highly portable but is usable in fixed locations or combination thereof. An aspect of the method and system includes the capability to distribute, modulate, aperture and spectrally analyze radiation emitted or absorbed by a volumetric target chemical species (solid, liquid or gas) or a target surface. Radiation is first collected by a single light gathering device, such as a lens, telescope, or mirror, and then distributed to multiple detectors through spectrally discriminating components and if desired through apertures to achieve this desired detection and identification.