Rough Surface Scattering Of Gauss-shell Model Beam

In the laser radar target detection, atmospheric turbulence is one of the main factors, which affecting the performance of target detection. In the transmission process, coherent light could be degradated into partial coherent light under the effect of atmosphere. The propagation properties of partial coherent light can effectively suppress the influence of atmosphere turbulence, such as the intensity twinkle, phase fluctuation etc. In the new system of laser coincidence imaging radar, using the partial coherent light as the light source. When describing the scattering characteristics of a target, the laser radar cross section(LRCS) is one of the most important quantity, which related to the target material, geometry, surface roughness and wavelength of incident light etc. It is defined under the condition that the incident light is partial coherent light. When the incident light is partial coherent light, the scattering characteristics of rough surface will change. The study of the scattering characteristics of target under partial coherent light is still in the initial stage, therefore, the LRCS angular distribution of gauss rough surface under the typical partial coherent light—Gauss Schell model beams(GSM) is researched.In the study of rough surface scattering of Gauss Schell model beams, the incident light can be viewed as the combination of Gauss beam and random phase. Using the angular spectrum theory, the incident light of Gauss Schell model beams expand into a set of plane waves. Based on the superposition principle of vector field and KA method in the rough surface scattering, the scattering field formula and the scattering coefficient formula is derived with the GSM beam incident light. The scattering coefficient of sample under different spatial coherent length and wavelength is analyzed. When the beam width or the coherent length of incident light increased to a certain degree, the results can be degenerated into coherent light.On the basis of theoretical research, the experimental measurement is carried out. Using the method of rotating ground glass, by changing the focal length of the collimating lens, partial coherent light with different spatial coherent length is produced. Using the measurement system of target scattering. The experimental data laser radar cross section of samples are obtained, comparison of different beam coherence length and different wavelength of incident and scattering cross section distribution of samples, such as 532 nm, 632.8nm and 650 nm.At last, make a comparison of the experiment data and the simulation results. Get a conclusion.