Characterization of Imaging System for Satellite-Borne Polarization Camera Based on Scientific Grade CCD

The cloud and aerosol polarization camera (CAPC) is an ultrawide angle satellite-borne polarization sensor, which adopts a scientific-grade array charge-coupled device (CCD) with the feature of smearing effect. To realize shorter exposure time and increase the dynamic range for the CCD imaging box of CAPC, the idea of charge dumping is introduced into the CCD timing driving design. Then, the design of power supply, driving timing, and analog front-end (AFE) is studied in detail. Finally, the comprehensive performance of the CCD imaging box is compared by utilizing the large aperture integrating sphere light source. The measurement results indicate that the exposure time of CCD is controlled between 5 and 80 ms, and the linearity error of CAPC at various bands is lower than 0.5%. Under the condition of 90% saturation exposure, the signal-to-noise ratio (SNR) of CAPC is 52.63 dB. The CCD dynamic range can achieve 62.91 dB. The experimental results meet the working requirements of the CAPC and verify the effectiveness of the CCD imaging design.