Liang Tianquan, Tang Qingxin, Yu Quanzhou
School of Geography and Environment, Liaocheng University, Liaocheng 252059, PR China.
Heliyon. 2023 Jul 19;9(8):e18454. doi: 10.1016/j.heliyon.2023.e18454. eCollection 2023 Aug.
Polarization is one of the fundamental properties of light, which has a wide range of applications and is developing rapidly. To meet the needs of polarization detection, different types of polarization instruments came into being. The precision of the polarization detection instruments is vital to the result analysis. In this paper, a full polarization imager is designed, and the radiometric calibration and polarization calibration of this instrument are studied. In radiometric calibration, the different numbers lights are set to verify the light intensity response of the imager. The mathematical model was constructed for numerical fitting, and the correlation between the fitted values and the measured values in the 490 nm, 550 nm, and 670 nm bands was above 0.99. Fixed the radiance of the integrating sphere, and adjusted exposure times. The correlation of the three bands is above 0.99, which verifies that the radiative stability of the imager is good. The polarimetric calibration system adopts the adjustable degree of polarization reference light source (APOL). The theoretical and measured values of the degree of polarization of reference light sources in three different bands are analyzed. The results show that the measurement accuracy of the 490 nm band is less than 2%. The precision of polarization measurement in the 550 nm band is less than 1.5%, and the precision of polarization calibration in the 670 nm band is less than 1%. The imager is verified to have high polarization calibration accuracy and meets the requirements of high-precision polarization detection.
偏振是光的基本特性之一，具有广泛的应用且发展迅速。为满足偏振检测的需求，不同类型的偏振仪器应运而生。偏振检测仪器的精度对于结果分析至关重要。本文设计了一种全偏振成像仪，并对该仪器进行了辐射定标和偏振定标研究。在辐射定标中，设置不同数量的光源以验证成像仪的光强响应。构建数学模型进行数值拟合，在490nm、550nm和670nm波段拟合值与测量值之间的相关性高于0.99。固定积分球的辐亮度，并调整曝光时间。三个波段的相关性均高于0.99，这验证了成像仪的辐射稳定性良好。偏振定标系统采用可调偏振度参考光源（APOL）。分析了参考光源在三个不同波段的偏振度理论值和测量值。结果表明，490nm波段的测量精度小于2%。550nm波段的偏振测量精度小于1.5%，670nm波段的偏振定标精度小于1%。验证了该成像仪具有较高的偏振定标精度，满足高精度偏振检测的要求。
