Design Of Image Acquisition And Pre-processing System For Space-based Solar Observation

Not affected by the Earth’s atmosphere and diurnal alternation,space-based solar observations can obtain more effective information about the Sun than ground-based observations,and help to minimize the adverse effects caused by solar activity.In this thesis,based on the Advanced Space-based Solar Observatory(ASO-S)project of CAS Pioneer II,the XQ5VFX130 T FPGA(Field Programmable Gate Array)and Gsense6060,a large-format,high speed image sensor,are used to design a highresolution image acquisition system for continuous monitoring of solar activity.Combing with a flare identification algorithm,this system can automatically detect solar flares and outburst locations,and perform high temporal resolution windowing imaging of outburst regions.Firstly,the overall design scheme of the image acquisition and pre-processing system was determined.According to the system index and working characteristics,the image acquisition means were determined through investigating the imaging systems of domestic and foreign space-based solar observation satellites.What’s more,the overall design scheme of the system was also formulated.Secondly,the logic design of the high-speed imaging system was completed.It includes the whole process from driving CMOS(Complementary Metal Oxide Semiconductor)to the final output data,which consists of six modules,such as CMOS driving control,CAN bus communication,data training based on input/output delay unit(IODELAY)and serial-parallel converter(ISERDES),DDR control,LVDS output and Camera Link output.Thirdly,the design of FPGA-based flare outbreak detection algorithm was completed.Including image median filtering,binning and threshold judgment,the algorithm adopts the idea of pipeline design.It realizes the real-time monitoring of flare outbreak and its location,and automatically switchs the working mode according to the processing result.Finally,the experimental verification of the image acquisition and pre-processing system was completed.The test and debugging results show that the system functions and performance meet the design requirements,the readout noise is better than 6 e-,and the dynamic range of HDR images synthesized with high and low gain images is better than 85 d B;the experimental results of the algorithm show that the system can automatically detect the solar flares and outburst positions in different situations in the full-disk,and enter or terminate the outburst mode according to the threshold conditions.The thesis realizes the drive and control of the large-format,high speed image sensor;the stable reception of 14-way high-speed serial data and matching the rate to the output interface;based on FPGA detection of flare outburst and its location,the focused recording of solar flares was realized.The experimental verification results show that the system indicators meet the task requirements,and the design idea of this thesis has certain reference value for the development of imaging and pre-processing system with large-format,high speed and high reliability.