Lidar Signals Induced by Spatial Variability of the Atmospheric Refractive Index(Over Lidar Signalen, Geinduceerd Door Ruimtelijke Variaties van de Atmosferische)

摘要

It is generally assumed that the intensity and the variation of lidar signals arecaused by reflection of laser light by atmospheric aerosols of which concentration and size distributions are spatially inhomogeneous. However, lidar signals with strong variations are sometimes also detected during periods with low aerosol concentrations. It will be shown in this report that these variations might also be caused by spatial inhomogeneities of the atmospheric refractive index, which in turn are determined by variations in the atmospheric temperature, pressure and humidity. Furthermore, it is shown that the amount of reflection from turbulence cells can also be derived from the refractive index structure parameter, Cn(2).