Research On Processing Technology Of Fine Guidance Star And High Frame Rate CMOS Electronics

The advanced space platforms at present are using Fine Guidance Sensor as the essential high precision sensor link of the Precision Image Stabilization System which provides high-quality attitude information for space platforms.The basic principle of FGS is: use FGS to image guide star in an array, then get centroid and generate an error signal by extracting the imaging information, at last, the error signal is fed back to the telescope’s Attitude Control System which is used to compensate the phase shift.High frame rate digital camera can slow down high speed process to the degree that human eyes can distinguish. It is a very powerful tool to study transient phenomena, and it has a very wide range of applications in industry, scientific research and military field. In recent years, many countries put a lot of effort in the field of high-speed camera and have achieved good results. Actively carrying out independent research and development of high resolution, high speed camera in China is of great significance in related fields.The main topic of the thesis is: image storage and transmission technology of high speed camera; development of large array, high frame rate, high precision, real-time guide star centroid extraction, development and testing of high bandwidth image transmission system based on fast image stabilization demand of the future large diameter high precision, wide field telescope. The breakthrough point of the thesis is: use FPGA to driver CMOS detector to finish image acquisition, processing and transmission. The thesis studies the hardware and software design and test of the whole system. The main works of the thesis are as follows:First of all, expound the background of the topic, survey the current study on the high frame rate and large area array camera, fine guide star technology and subpixel centroid localization algorithm at home and abroad; Secondly, describe the specifications and requirements of the system in detail, design high frame rate CMOS image acquisition, processing and transmission system based on the requirements of the specifications; The third, complete the system hardware circuit design, including high-speed signal integrity simulation, the output circuit design of front-end detector, circuit design of information processing, power module circuit design; The fourth, complete the software programming of the system, including the hardware description language programming of FPGA platform, the host computer programming; The fifth, complete the test work of the guide star centroid extraction system, including the debug of the system hardware and software, the test of the specifications of the system. The experimental results show that: high frame rate guide star centroid extraction system is able to extracte centroid information in real time and with high precision according to the requirements of the system specifications, and it can transmit images and centroid information to the upper computer for saving or displaying with high frame rate. The system has achieved the research goals and the requirements.The innovation points of the thesis lie in:1 On the basis of the study of Fine Guidance Sensor at home and abroad, this thesis puts forward a technical proposal which uses active pixel CMOS detector as the array sampling unit, and uses FPGA as the core processor for real-time image processing. This thesis also constructs and completes the combination of software and hardware for the fine guide star verification system based on one single detector. The research of this thesis lays practical foundation for China’s independent research and development of space telescope phase shift compensation system.2 To meet the real-time processing and high accuracy demands of the Fine Guidance Sensor, this thesis builds a complete hardware platform for the fine guide star detection system, including star image acquisition, buffering, processing and transmission. This hardware platform has strong real-time data processing ability, and it can also realize image and data transmission from the platform to the host computer through high-bandwidth optical fiber interface and Gigabit Ethernet interface.3 This thesis completes the design of fine guidance sensor verification system, and it detects the frame rate of centroid extraction and also the dynamic and static precision of centroid division. The results show that the frame rate of the centroid extraction and static precision of centroid division are both better than the expected design specifications.