基于FPGA的空间太阳磁像仪自校正稳像系统研制

太阳磁像仪是开展太阳磁场观测研究的核心仪器,其中的稳像系统是空间太阳磁像仪的关键技术之一,针对深空探测卫星系统对载荷重量、尺寸限制严苛的要求,设计了基于图像自校正方法的稳像观测系统.介绍了一套基于现场可编程门阵列(Field-Programmable Gate Array, FPGA)和数字信号处理器(Digital Signal Processor, DSP),通过基于自相关算法的高精度稳像方法设计,并结合精确偏振调制、准确交替采样控制等系统软硬件设计,克服由于卫星平台抖动、指向误差等因素造成的图像模糊,实现实时相关、校正、深积分的稳像观测系统.针对像素尺寸为1 K×1 K、帧频为20 fps的CMOS (Complementary Metal Oxide Semiconductor)探测器,实现了1像元以内的实时稳像观测精度.在完成实验室测试后, 2021年6月18日在国家天文台怀柔太阳观测基地35 cm太阳磁场望远镜上开展了实测验证,结果表明该系统能够有效地完成太阳磁像仪自校正稳像观测,获得了更高分辨率的太阳磁场数据.稳像系统的成功研制不仅可以为深空太阳磁像仪的研制提供轻量化、高...

Development of Image Self-correlation System Based on FPGA for Space Solar Magnetograph

The solar magnetograph is a key instrument for observing and studying the solar magnetic field, and the image correlation system of the magnetograph directly is one of the key technologies in the instrument, affecting the accuracy and spatial resolution of the data. In view of the strict requirements of the deep space exploration satellite system on the weight and size restrictions, an image self-correlation system for space solar magnetograph was designed. The system contains the accurate polarization modulation, accurate alternating sampling control and image correlation algorithm, to overcome image blur caused by satellite platform jitter, to realize the image real-time correlation, so as to obtain higher resolution solar magnetic field data. The system adopts modular design and mainly includes six parts: camera and KD*P high-voltage control, image data conversion, communication function on FPGA (Field-Programmable Gate Array), image correlation, communication function on DSP (Digital Signal Processor), and control system. The solar magnetic field data can be obtained by one button through the control system software. At present, the real-time image correlation observation function (20 frame/s and 1 Ktimes1 K area array) is realized based on FPGA + DSP architecture, and achieve stable accuracy within 1 pixel. On June 18, 2021, the ground experimental test was carried out on the 35-cm solar magnetic field telescope in Huairou solar observing station. The data results show that the image self-correlation system can effectively correct and integrate the image offset in real time, and obtain higher resolution solar magnetic field data. In addition, the system does not depend on the hardware devices such as the deflection mirror in the traditional image correlation system, and can be directly embedded into the onboard data acquisition system, to reduce the weight and power consumption of the system, and improve the reliability of the on-orbit operation.