Research On Active Polarization Imaging And Performance Analysis In Vertical Atmospheric Dispersion System

With the development of science and technology,how to obtain clear images and effective information in complex environment has become a very important topic.In recent years,with the development of polarization technology,the use of polarized light as a carrier of information transmission is playing an increasingly important role in the fields of information transmission,underwater detection,remote sensing,military target detection and biomedicine.Polarization,like the intensity,wavelength and phase of light,is a fundamental physical property of light.Compared with the traditional imaging methods,polarization imaging can not only obtain the irradiance information of the target,but also the polarization information of the target,thus improving the ability of detecting and rebuilding the target image from the complex scene.However,polarized light must be scattered and absorbed when it is transmitted in a complex environment.In this regard,the predecessors mainly used the improved algorithm based on the scattering model to remove the scattered light to optimize the image,and did not restore the original image from the nature of light transmission.Based on the layered scattering theory and Monte Carlo algorithm,this paper constructs an atmospheric scattering model and analyzes the transmission and transformation characteristics of polarized light in the atmospheric dispersion system.Based on the improved polarization recovery algorithm,the uniqueness of the Mueller matrix of the atmospheric scattering system is used to recover the original image of the target.According to the simulation results,compared with the traditional imaging method,clearer images can be obtained,especially for larger optical thickness.Furthermore,we also explored the applicable scale of Mueller matrix for image restoration,and found that even if there is some fluidity in the atmosphere,the target image can be recovered well within a certain range.We also discuss the effect of transmission wavelength on image quality.The main research contents of this paper are as follows:(1)Construction of atmospheric simulation model and analysis of polarization transmission characteristics.Based on the basic theory of polarization and scattering,the atmospheric layered scattering algorithm and Monte Carlo algorithm are used to build the simulation transmission model,and the simulation calculation is carried out with the actual atmospheric parameters.Based on the simulation 3-d diagram,the variation law of linear and circularly polarized light in the process of up and down transmission is studied,and the transmission characteristics and polarization transformation characteristics of linear and circularly polarized light in different environments are calculated.(2)The modified polarization retrieve algorithm is used to image atmosphere remote sensing.The modified polarization retrieve algorithm was proposed.In view of the high complexity and long distance transmission characteristics of the atmospheric environment,we calculate the scatterer effective Mueller matrix by emitting a variety of polarized light to retrieve the target image.By changing the optical thickness of the simulation environment,it can be compared with traditional imaging.Finally,the effectiveness and superiority of our method are verified by using image quality index.(3)The effects of Mueller matrix retrieve scale,wavelength and different polarized light on imaging quality were studied.The atmospheric fluidity leads to the time-varying of Mueller matrix.In order to prove the practicability of the method in this paper,we use the initial Mueller matrix to retrieve the target image in different atmospheric environments and calculate its retrieve scale.In addition,different wavelengths or polarized states of light have different scattering characteristics during transmission.By emitting light of different wavelengths and different polarization states,we analyzed the effect on the image quality.