High-Spectral Resolution Lidar Measurement of Tropospheric Backscatter Ratio Using Barium Atomic Blocking Filters

Abstract Initial measurements of the aerosol backscatter ratio using a new atomic barium filter (FWHM from 2.0–3.0 GHz at 553.7 nm) in conjunction with a narrowband-pulsed dye laser system are reported. Using analog detection and a 0.2 m diameter receiving telescope, variation of about 10 percent are obtained over a range of 0.25–2.0 km with 30 m resolution within two minutes. Dense regions of aerosols (e.g., clouds) as thin as 10 m and at ranges of up to 6.5 km have been observed in the backscattered signal. Under appropriate climate conditions, sequential measurements of backscatter ratio profiles can be used to follow cloud dispersal dynamics. Techniques for improving accuracy and the potential of using this technique for measuring temperatures throughout the troposphere are discussed.