The availability of new laser sources that are tunable in the IR spectral region opens new perspectives for differential absorption lidar (DIAL) measurements. A region of particular interest is located in the near IR, where some of the atmospheric pollutants have absorption lines that permit monitoring of emissions from industrial plants and in urban areas. In DIAL measurements, the absorption lines for the species to be measured must be carefully chosen to prevent interference from other molecules, to minimize the dependence of the absorption cross section on temperature, and to optimize the measurements with respect to the optical depth. We analyze the influence of these factors and discuss a set of criteria for selecting the best pairs of wavelengths (λ<sub>on</sub> and λ<sub>off</sub>) to be used in DIAL measurements of several molecular species (HCl, CO, CO<sub>2</sub>, NO<sub>2</sub>, CH<sub>4</sub>, H<sub>2</sub>O, and O<sub>2</sub>). Moreover, a sensitivity study has been carried out for selected lines in three different regimes: clean air, urban polluted air, and emission from an incinerator stack.
© 2000 Optical Society of America
(280.0280) Remote sensing and sensors : Remote sensing and sensors
(280.1120) Remote sensing and sensors : Air pollution monitoring
(280.1910) Remote sensing and sensors : DIAL, differential absorption lidar
(280.3640) Remote sensing and sensors : Lidar
Paolo Francesco Ambrico, Aldo Amodeo, Paolo Di Girolamo, and Nicola Spinelli, "Sensitivity Analysis of Differential Absorption Lidar Measurements in the Mid-Infrared Region," Appl. Opt. 39, 6847-6865 (2000)