Research On Modeling And Acquisition Of Skylight Polarization Patterns In Real Scene

The skylight polarization patterns contains abundant space-time information.By studying the modeling and measurement methods of the skylight polarization patterns,analyzing its distribution characteristics,we can obtain time information,spatial orientation information,atmospheric composition and other information.It has a significant research in the fields of autonomous navigation,target detection,atmospheric remote sensing,atmospheric optical analysis using polarized light significance.In this thesis,by analyzing the actual distribution of the skylight polarization patterns after the polarization imaging system,a modeling method of the air polarization mode representation based on the imaging theory is proposed.Considering that the skylight polarization patterns after the polarization imaging system will be distorted,an analysis method of the degree of the skylight polarization patterns distortion based on the imaging theory is proposed.In addition,an adaptive acquisition method of skylight polarization patterns is proposed on the acquisition level of measured data of skylight polarization patterns.The main work of this thesis includes:(1)Based on the theory of Rayleigh scattering,the distribution of the skylight polarization patterns in the imaging plane in three-dimensional space is analyzed,and the characterization model of the skylight polarization patterns based on the imaging theory is established by combining the skylight polarization patterns with the imaging system.Then the accuracy of the analytical model is verified by comparing the model with the Rayleigh mode.(2)Based on the analysis of the internal structure and imaging results of the imaging system and fisheye lens,this paper discusses the distortion phenomenon of sky light after entering the imaging system,studies its distortion principle,analyzes the degree of distortion of the skylight polarization patterns based on the three imaging modes,and puts forward the analysis method of the skylight polarization patterns distortion based on the imaging theory.(3)Based on the Stokes method to obtain the polarization state,an adaptive method to obtain the skylight polarization patterns is proposed.The single channel time-series polarization information measuring instrument is used as the experimental instrument to rotate a certain number of polarizers and select a certain number of pixels.The algorithm to obtain the measured skylight polarization patterns is improved by using the Gauss Newton method and the alternating minimization iteration method,so that no need to know the skylight polarization patterns can be obtained by the rotation angle of the channel polarizer.