Monitoring of aerosol inhomogeneities parameters in atmosphere at 355 nm

We present the results of experimental studies of aerosol inhomogeneities characteristics in atmosphere planetary boundary layer (PBL) at eye-safety 355 nm wavelength. For developed lidar system for monitoring aerosol inhomogeneities technical specifications of the key components are described. It includes a diode-pumped solid state (DPSS) laser with pulse energy 1.3 mJ, duration 7 ns and pulse repetition rate up to 500 Hz, Cassegrian telescope with prime mirror diameter 100 mm and photomultiplier tube (PMT) as photodetector. Lidar provides registration of aerosol elastic backscattering signal with high spatial (0.6 m) and temporal (0.002 s) resolution up to 1 km depending on atmosphere condition. The preprocessing algorithm to form lidar signal variation coefficient fields in "Range-Time" coordinates is discussed. Examples of these fields for different weather conditions are presented. Accumulated measurement data from 2015 to 2017 for spring-autumn period in Moscow region was analyzed and for more than 1 500 inhomogeneities shown histograms of size and average contrast. The obtained results are compared with the known measurement data in the visible spectral range.