Experimentally Researched Statistical Characteristics of Aerosol Lidar–Recorded Laser Signal at the Eye-Safe Wavelength of 0.355 μm

Abstract

To date the developed and newly created laser systems (radar, range finding, altimetry, etc.) use (to ensure eye safety) the infrared (> 1.4 μm) range. At the same time, an ultraviolet range is of interest too. The most promising here is a wavelength of 0.355 μm (third harmonic of a YAG laser: Nd), since the atmospheric ozone absorption is still low (in the spectral range of 0.25 - 0.38 μm ozone absorption is increased with decreasing wavelength). The paper presents an experimental study of the statistical characteristics of lidar signals at the eye-safe wavelength of 0.355μm. As the statistical characteristics, were used a mean value and a standard deviation of lidar signal. Aerosol inhomogeneity available in the atmosphere has impact on the statistical characteristics of the received signal. Thus, the analysis of these characteristics allows us to view that in the atmosphere there is aerosol inhomogeneity. The article shows that the standard deviation of the signal caused by inhomogeneity is much higher than the standard deviation caused by the shot noise of signal and background as well as by the noise of electronic circuit. The article gives examples of the field of a coefficient of variations. After filtration the field also permits viewing the available atmospheric inhomogeneity of the backscattered signal.