Round-the-clock temperature profiling in the troposphere with Raman lidar

We discuss the Raman-lidar technology of acquiring temperature profiles of the atmosphere that we have recently developed to facilitate the day-time temperature measurements with lidar. Information on the temperature profile is retrieved in this approach from the intensity ratio of two spectral portions of pure rotational Raman spectrum (PRRS) of molecular nitrogen isolated with a tandem of a Fabry-Perot interferometer and a double grating monochromator. Key items of the lidar technique, as well as of the lidar operation are discussed in detail. Also we discuss some instrumental effects due to imperfection of optical components that can cause a range-dependent bias of the atmospheric temperature values acquired with lidar relative to true ones. It is experimentally shown, in particular, that optical scrambling of the radiation flux coming from the lidar optical receiver is an efficient means to remove this bias.