Optical Engineering • Open AccessTechnique for passive scene imaging of gas and vapor plumes using transmission-waveband modulation
A new approach to locating gas and vapor plumes is proposed that is entirely passive. By modulating the transmission waveband of a narrow-band filter, an intensity modulation is established that allows regions of an image to be identified as containing a specific gas with absorption characteristics aligned with the filter. A system built from readily available components was constructed to identify regions of NO2. Initial results show that this technique was able to distinguish an absorption cell containing NO2 gas in a test scene.