The directional polarimetric camera (DPC) is a polarization sensor with the characteristics of ultra-wide-angle and low-distortion imaging. The multi-angle polarization information is helpful to obtain the spatial distribution of target radiation, and multiple data fusion relies on the non-uniformity calibration of image plane. The non-uniformity consists of many factors such as lens, detector assembly, spatial stray light, etc. The single correction method can not distinguish the error source effectively. In consideration of the in-flight operation mode of DPC based on the adjustment of exposure time, the non-uniformity correction method of the detector based on multi parameters is proposed. Through the electro-optical performance measurement system of the CCD detector, the sensitive factors such as temperature, dark current, exposure time and spectral response are obtained. After a series of preprocessing of the image including removal of dark signal, removal of smearing effect and temperature compensation, the non-uniformity calibration based on multi-parameters is imposed on the detector. The low-frequency unbalanced response difference of the image surface is eliminated, and the high-frequency difference is effectively suppressed. The experimental results show that the photo response non-uniformity of 95% full well single frame data is reduced from 2.86% to 0.36%. After correction, the data noise is shown as shot noise, and the detector has good ability of dynamic range adjustment. The non-uniformity calibration by the proposed method can offer data support for the instrumental calibration and in-flight fast calculation, and provide effective reference for the subsequent polarization remote sensing instruments.

中文翻译：

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定向偏振相机星载CCD的非均匀性标定方法

定向偏振相机（DPC）是一种具有超广角和低失真成像特性的偏振传感器。多角度偏振信息有助于获得目标辐射的空间分布，多数据融合依赖于像平面的非均匀性校准。不均匀性由许多因素组成，例如透镜，检测器组件，空间杂散光等。单一校正方法无法有效地区分错误源。考虑到基于曝光时间调整的DPC空中运行模式，提出了基于多参数的探测器非均匀性校正方法。通过CCD检测器的电光性能测量系统，温度，暗电流，获得曝光时间和光谱响应。在对图像进行一系列预处理（包括消除暗信号，消除拖尾效应和温度补偿）之后，将基于多参数的非均匀性校准应用于检测器。消除了图像表面的低频不平衡响应差异，并且有效地抑制了高频差异。实验结果表明，95％全孔单帧数据的光响应不均匀度从2.86％降低到0.36％。校正后，数据噪声显示为散粒噪声，检测器具有良好的动态范围调节能力。所提出方法的非均匀性校准可以为仪器校准和飞行中快速计算提供数据支持，