Experimental And Simulation Investigation On Retro-reflective Laser Imaging In Turbulent Atomosphere

It is necessary to understand and master the spatial structure characteristics of the optical turbulence intensity in the space-time distribution and feature scales,and to obtain a qualitative and quantitative description of the turbulence effects in atmospheric transport of light waves.At the same time,this research has important academic significance and extensive application value in the fields of laser radar detection,guidance,and confrontation.In this paper,the laser spot detection experiment was carried out on a 1km transmission path in a turbulent atmosphere under typical weather conditions using a red laser,a 3M microcrystalline prism array reflector and a telephoto high speed CCD.Scintillmeter and atmospheric coherence meter for 24-hour real-time monitoring of turbulence parameters.A preliminary discussion was made on some basic issues in the laser atmospheric transmission.The intensity distribution of laser echoes was visually analyzed,and the differences in the laser spot shape of the reentry path under different turbulent intensities were compared;the spot image was analyzed using a certain period of time.Spectral intensity probability density distribution;The relationship between the scintillation index in the receiving aperture and the receiving aperture is further studied under the turbulence effect,and the turbulent refractive index structure constant calculated from the scintillation index is compared with the real-time monitoring data.The turbulent refractive index structure constant obtained by this method and the measured value of the laser scintillometer have a good consistency in the changing trend.A complete laser transmission link simulation model was established based on the experimental system.The single-pass and two-way transmission processes on the Gaussian beam horizontal path in the turbulent atmosphere were simulated by the step-by-step Fourier transform algorithm.Statistical analysis was performed on a large number of laser spots simulated.Compared with the experimental values,the influences of the selection of the link model,the turbulence intensity and the target roughness on the statistical characteristics of the beam are analyzed,and the differences in the statistical properties of the beams between one-way and two-way paths are compared.The experimental system established in this paper can not only be used to observe the complete far-field laser spot affected by the atmospheric turbulence,but also can be used as a single-end atmospheric optical turbulence parameter imaging and detection technology through quantitative theoretical modeling.Therefore,the research results of this paper have important guiding significance and reference value.