Dual differential absorption lidar for the measurement of atmospheric SO_(2) of the order of parts in 10~(9)

摘要

Vertical concentration profiles of atmospheric SO_(2) of the order of parts in 10~(9) (ppb) were measured by a multiwavelength differential absorption lidar system. The error that was due to O_(3) and aerosols was successfully reduced by a three-wavelength dual differential absorption lidar (DIAL), and a SO_(2) concentration of 1.2 ppb for 2400-3000-m altitude was obtained with 300-m range resolution. The measurement error in dual DIAL was estimated to be <1.1 ppb when several factors were considered. The influence of O_(3) on SO_(2) measurement error was experimentally evaluated from simultaneous measurements of atmospheric SO_(2) and O_(3) by two conventional DIAL pairs, each using two wavelengths.