Atmospheric temperature profiling in the presence of clouds with a pure rotational Raman lidar by use of an interference-filter-based polychromator

A Lidar polychromator design for the measurement of atmospheric temperature profiles in the presence of clouds with the rotational Raman method is presented. The design utilizes multicavity interference filters mounted sequentially at small angles of incidence. Characteristics of this design are high signal efficiency and adjustable center wavelengths of the filters combined with a stable and relatively simple experimental setup. High suppression of the elastic backscatter signal in the rotational Raman detection channels allows temperature measurements independent of the presence of thin clouds or aerosol layers; no influence of particle scattering on the Lidar temperature profile was observed in clouds with a backscatter ratio of at least 45. The minimum integration time needed for temperature profiling with a statistical temperature error of +/-1 K at, e.g., 20-km height and 960-m height resolution is 1.5 h. (C) 2000 Optical Society of America OCIS codes: 280.3640, 300.6450.