Laser echo signal amplification in a turbulent atmosphere

A lidar system for registration of laser return amplification in a turbulent atmosphere due to backscatter amplification effect is considered in this paper. In the system, two receiving channels are used. One of them (axial) coincides with the transmitter channel, while another channel (nonaxial) receives the backscattered radiation at a small angle to the probing beam axis. The power ratio of the echo signal recorded in the axial channel to that recorded in the nonaxial one is a measure of the return amplification. The results of long-duration lidar atmospheric experiments show that the power of the echo signal registered in the axial channel usually exceeds that in the nonaxial one.