Design Of SCMOS Imaging System For Space-borne Polarization Spectral Camera

In polarized spectral imaging technology,high dynamic range and low noise detectors are one of the key technologies.Typically,CCD is the first choice for detectors because of its high sensitivity,low noise,large dynamic range,and other characteristics.However,with the continuous progress of CMOS image sensor technology,sCMOS image sensors can now rival CCD,and have many advantages in high integration and low power consumption.Therefore,based on the sCMOS image sensor,this paper designs a high-reliability,lownoise imaging system for the atmospheric correction project of polarized spectral cameras,focusing on the hardware and software design of the imaging system.Firstly,the theory and implementation of polarized spectral imaging technology were studied,and combined with the on-orbit working mode and characteristics of the camera,the scheme of staring imaging and filter wheel spectrometer was determined,and the design index requirements of the system were given.At the same time,the key components of the system,sCMOS detector and main control chip FPGA,were analyzed and selected.Then,based on the sCMOS image sensor of G-pixel company,the hardware circuit design and software design were carried out.The hardware circuit adopts the design architecture of FPGA plus SRAM cache,and the circuit is designed in modules according to functions,including power supply module,FPGA main control module,focal plane module,SRAM storage module,and interface module.The software part completed the module design of SPI configuration,detector driving,data receiving and storage,and LVDS data output.The correctness of each module was verified by simulation after the design was completed.In addition,a dynamic delay imaging method was proposed to improve the polarization azimuth deviation problem under the filter wheel spectrometer mode,and the effect was verified by polarization azimuth angle test,which shows that the method can effectively reduce the polarization azimuth deviation.Finally,the functional and performance tests of the imaging system were carried out to prove the feasibility and effectiveness of the system and meet the design index requirements.The significance of this research is to improve the performance of the on-board polarized spectral camera and provide reference for the design of similar instruments,and provide support for research in related fields.