Investigation on the distribution of target echo based on point target atmospheric scintillation

In the process of propagation in the atmosphere, the laser is randomly disturbed by atmospheric turbulence, which leads to the laser intensity scintillation effect, and influences imaging lidar's target detection. In order to explore the influence of atmospheric turbulence on the power distribution of target echo, in this paper, a numerical simulation method was used to investigate the target-echo power distribution caught by imaging lidar of 5 m×5 m gray ceramic tile in the situation of turbulence. Based on the FFT spectral inversion method which can construct atmospheric turbulence phase screens, lidar equation and the analyzing of the aperture smoothing theory on scintillation effect, the target echo, which is in front of the detector, caught by 128×128-pixel imaging lidar with different turbulence intensity was simulated; at the distance of 2 000 m, and the atmospheric refractive index structure constant is 2×10^-16 m^-2/3- 2 ×10^-13 m^-2/3, the target echo-power normalized mean square deviation relative to which considered the situation of no turbulence was 0.72 -0.93, and the actual atmospheric refractive index structure constant which is 3.32×10^-16 m^-2/3 was obtained, under actual conditions, at the distance of 500-2 000 m, the target echo-power normalized mean square deviation relative to which considered the situation of no turbulence was 0.19 -0.81, Simulation experimental results show that, under the strong atmospheric turbulence and long-distance transmission conditions, considering the influence of atmospheric turbulence on the laser echo, the laser echo power distribution fluctuates larger relative to which not considering the influence of turbulence, so the influence of turbulence on imaging lidar target detection can't be ignored.