Backscatter absorption gas imaging (BAGI) is a technique that uses infrared active imaging to generate real-time video imagery of gas plumes. We describe a method that employs imaging at two wavelengths (absorbed and not absorbed by the gas to be detected) to allow wavelength-differential BAGI. From the frames collected at each wavelength, an absorbance image is created that displays the differential absorbance of the atmosphere between the imager and the backscatter surface. This is analogous to a two-dimensional topographic differential absorption lidar or differential optical absorption spectroscopy measurement. Gas plumes are displayed, but the topographic scene image is removed. This allows a more effective display of the plume image, thus ensuring detection under a wide variety of conditions. The instrument used to generate differential BAGI is described. Data generated by the instrument are presented and analyzed to estimate sensitivity.
© 2000 Optical Society of America
(010.3640) Atmospheric and oceanic optics : Lidar
(280.1120) Remote sensing and sensors : Air pollution monitoring
(280.1910) Remote sensing and sensors : DIAL, differential absorption lidar
(280.3420) Remote sensing and sensors : Laser sensors
(280.3640) Remote sensing and sensors : Lidar
Peter E. Powers, Thomas J. Kulp, and Randall Kennedy, "Demonstration of Differential Backscatter Absorption Gas Imaging," Appl. Opt. 39, 1440-1448 (2000)