A polarimetric calibration method based on non-polarized light source was proposed to solve the problem of polarimetric calibration of the multi-channel polarimetric imager.Through the study of the interaction between polarized beam and optics, the vector radiative transfer model of multi-channel polarimetric imager was deduced and the calibrated parameters were determined.The key parameters such as absolute radiometric calibration coefficients of center viewing field, polarization degree of optical lenses and relative transmittance with system low frequency were calibrated based on the vector radiative transfer model by application of polarimetric effects of the system with non-polarized light source.By analyzing the calibration result, the Mueller matrix of full field of view was solved.Furthermore, the accuracy of polarimetric calibration on typical field of view was verified with a light source with variable polarization degrees.The results show that the polarimetric calibration method based on non-polarized light source can effectively improve the polarization calibration efficiency of multi-channel polarimetric imager with the measured error of polarization less than 1% and the target degree of polarization less than 20%, thus meeting the requirements of measurement accuracy of atmospheric aerosol.%为了解决多通道型偏振成像仪的偏振定标问题,提出了一种基于积分球无偏光源的偏振定标方法.通过研究偏振光束与光学器件的相互作用,推导出多通道型偏振成像仪的矢量辐射传输模型,确定了需要标定的参数.运用无偏光源标定系统的偏振效应,基于矢量辐射传输模型对中心视场绝对辐射定标系数、光学镜头起偏度和系统低频相对透过率等关键参数进行了标定,通过分析标定结果求解了系统全视场的穆勒矩阵.最后,使用可调偏振度光源验证了仪器典型视场的偏振定标精度.研究结果表明,基于无偏光源的偏振定标方法可以有效提高多通道型偏振成像仪的偏振定标效率;经偏振定标后仪器在目标偏振度低于20%时的偏振测量误差小于1%,满足大气气溶胶测量精度的要求.
展开▼
