多角度偏振成像仪温度校正方法

Temperature-Correction Method for Directional Polarimetric Camera

多角度偏振成像仪温度变化是影响辐射定标精度的因素之一,科学遥感数据处理首先进行温度校正。通过成像仪工作原理和偏振测量模型分析了温度变化的影响,结合热控设计和热真空实验情况,针对辐射测量的影响制定了温度补偿校正方法。设计覆盖在轨不同阶段的温度响应测试方案,监测影响实验数据的测试光源等外界条件,有效消除探测器帧转移效应影响,获取辐射定标系数与温度变化响应之间的关系。依据实验和在轨数据分析,通过暗背景通道实时测量及辐射响应系数补偿的温度校正方法,使温度变化带来的辐射测量误差减小至0.1%,满足在轨辐射校正需求。

Temperature change affects the accuracy of the radiometric calibration of the directional polarimetric camera(DPC).The first step in scientific remote-sensing data processing is temperature correction.Herein,we analyze the influence of temperature change based on the DPC working principle and the polarization-measurement model.Combined with the thermal-control design and thermal vacuum test,we develop a temperature-compensation-correction method aiming at the influence of radiation measurement.We design a temperature-response test scheme for in-orbit temperature conditions at different stages to monitor external conditions which affect test data and effectively eliminate the influence of the detector-frame transfer effect,and obtain the relationship between the radiation calibration coefficient and the temperature-change response.According to the analysis of experimental data and in-orbit data,the radiation measurement error caused by temperature change reduces to less than+0.1%through real-time measurement of the dark-background channel and through the temperature-correction method of radiation-response-coefficient compensation,which meets the requirements of in-orbit radiation correction.