One embodiment of the disclosure relates to a detection system including a chemical taggant and a detector. The chemical taggant may be a chemical not substantially present in an untagged target exhaust plume and able to be disposed in the exhaust system of a target and to enter the exhaust plume of the exhaust system in detectable quantities. The chemical taggant may have one or more distinct energy signatures, such as optical energy signatures, that allow its detection. The detector may be able to detect at least one of these one or more energy signatures of the chemical taggant in the exhaust plume. Another embodiment relates to a method of detecting a target by disposing a chemical taggant in the exhaust system of the target and then detecting the chemical taggant.