Research On Spectral Polarization Imaging Measurement Technology Of Coded Aperture Based On Intensity Modulation

Spectral polarization imaging technology is a new information acquisition and application technology that integrates Spatial two-dimensional image,spectrum and polarization of target.Based on the spectral imaging technology,this technology increases the polarization characteristics of the target to be measured.The effective acquisition of multi-dimensional information has significant advantages in target recognition detection,and can be widely used in military detection,medical detection and atmospheric environmental monitoring.In order to solve the problems of scanning and information loss in the existing spectral polarization imaging measurement technology,a new spectral polarization imaging measurement method combining intensity modulation technology and coded aperture spectral imaging technology is proposed in this paper,which achieves the acquisition of spectral polarization information in a single measurement.This paper will mainly carry on the elaboration research from the following aspects.Firstly,based on the compressed sensing theory,which is the core of coded aperture spectral imaging technology,The three basic problems of compressed sensing are studied in detail:sparse representation,measurement matrix selection and signal reconstruction.The working principle and performance of the coded aperture spectral imaging system are deeply analyzed,which provides a solid theoretical basis for further study of spectral polarization imaging measurement.Secondly,a new technique based on intensity modulation for Spectral Polarization Imaging measurement of coded aperture is proposed.Based on the analysis of the polarization characteristics of light and its representation method,the modulation principle of intensity modulation module is deduced and analyzed by Stokes vector representation.A achromatic1/4 wave plate,a multi-stage phase retarder or two multi-stage phase retarders are selected as the core of intensity modulation module respectively.Two sets of spectral polarization imaging measurement systems are designed to select Stokes parameters S,respectively,using an achromatic 1/4 wave plate and a multi-stage phase retarder or two multi-stage phase retarders as the core of the intensity modulation module.The measurement of the first three parameters and all four parameters in the Stokes parameter S=[S₀,S₁,S₂,S₃]can be realized separately.The whole process of polarization spectrum modulation and modulation spectrum data cube compression coding is modeled,and the reconstruction of polarization spectrum image is theoretically analyzed.The two-step iterative shrinkage threshold algorithm is used to reconstruct the spectral data cube,and the reconstructed modulation spectrum is demodulated to restore the original Stokes parameters.Finally,the algorithm simulation of the coded aperture spectral polarization imaging measurement technology based on intensity modulation is carried out by using MATLAB,including polarization modulation process,spectral image coding compression process,data cube reconstruction process and polarization spectrum demodulation process.The simulation results show that the polarization spectral imaging measurement technology has the ability to efficiently acquire spatial,spectral and polarized four-dimensional information,and effectively validates the feasibility of the coded aperture spectral polarization imaging measurement technology,and provides a theoretical basis for further construction of the experimental system.