Lidar sensing of the turbulence based on the backscattering enhancement effect

Backscattering enhancement (BSE) effect is due to the fact that both the initial and back-scattered waves propagate through the same inhomogeneities of the refractive index. Mean value of the back-scattered intensity is higher than it would be with the same obstacle but no inhomogeneities. This effect is named backscattering enhancement (BSE) effect. Numerical modeling of lidar that based on BSE effect was carried out in Rutov-Obukhov approximation in our work. The integral equation was considered which bundles up the distribution of turbulence intensity throughout the space between the source and a scatterer. Coefficient BSE was determined as ratio of relation dispersions of radiation intensity fluctuation that scattered straight back and at an angle. BSE coefficient does not depend on the nature of scatterings in cases of aerosol or molecular scatterers. As example variants of turbulence intensity distribution Cn2 between sources in form select layer or boundaries of half-space with enhanced turbulence intensity scatterers were considered. Possibility of detection the sort out the regions with enhanced turbulence intensity was showed in the case isotropic turbulence for molecular or aerosol scatterings. Inhomogeneous distribution of turbulence intensity is reliably picked out on dependence of BSE coefficient on distance between source and probing laser beam. The lidar scheme for BSE measurements with space modulation of probing beam is suggested. It allows suppressing systematic errors. Lidar allows measure BSE coefficient along with the routine lidar sensing. The dependence of BSE coefficient on the line along propagation path has considered for finite receiving aperture and finite diameter of probing laser beam. The results of modeling demonstrate that BSE measurements make it possible to remotely sort out the regions with enhanced turbulence intensity at distances determined by the maximum sensing range.