Li Zhengqiang, Li Kaitao, Li Li, Xu Hua, Xie Yisong, Ma Yan, Li Donghui, Goloub Philippe, Yuan Yinlin, Zheng Xiaobing
Appl Opt. 2018 Feb 10;57(5):1011-1018. doi: 10.1364/AO.57.001011.
Polarization observation of sky radiation is the frontier approach to improve the remote sensing of atmospheric components, e.g., aerosol and clouds. The polarization calibration of the ground-based Sun-sky radiometer is the basis for obtaining accurate degree of linear polarization (DOLP) measurement. In this paper, a DOLP calibration method based on a laboratory polarized light source (POLBOX) is introduced in detail. Combined with the CE318-DP Sun-sky polarized radiometer, a calibration scheme for DOLP measurement is established for the spectral range of 440-1640 nm. Based on the calibration results of the Sun-sky radiometer observation network, the polarization calibration coefficient and the DOLP calibration residual are analyzed statistically. The results show that the DOLP residual of the calibration scheme is about 0.0012, and thus it can be estimated that the final DOLP calibration accuracy of this method is about 0.005. Finally, it is verified that the accuracy of the calibration results is in accordance with the expected results by comparing the simulated DOLP with the vector radiative transfer calculations.
天空辐射的偏振观测是改善大气成分（如气溶胶和云）遥感的前沿方法。地基太阳-天空辐射计的偏振校准是获得准确线性偏振度（DOLP）测量值的基础。本文详细介绍了一种基于实验室偏振光源（POLBOX）的DOLP校准方法。结合CE318-DP太阳-天空偏振辐射计，针对440-1640nm光谱范围建立了DOLP测量的校准方案。基于太阳-天空辐射计观测网络的校准结果，对偏振校准系数和DOLP校准残差进行了统计分析。结果表明，该校准方案的DOLP残差约为0.0012，由此可以估计该方法最终的DOLP校准精度约为0.005。最后，通过将模拟的DOLP与矢量辐射传输计算结果进行比较，验证了校准结果的准确性与预期结果一致。
