空间太阳望远镜图像积分中1 bit相关器的研究

空间太阳望远镜(SST)系统采用图像积分方法提高太阳矢量磁图的信噪比(SNR).在图像积分过程中,基于图像强度信息的相关器难以满足航天应用中系统实时性和低资源消耗要求,为此提出使用1 bit相关器实现图像快速相关运算.1 bit相关算法以异或逻辑运算代替常规算法中的乘法,提高了运算速度,同时减小硬件实现复杂度.针对太阳米粒图像,给出1 bit相关算法方案,并研制出基于FPGA DSP架构的相关器.测试结果表明,该相关器的算法精度、相关运算时间均能满足SST需求,而FPGA资源消耗仅为基于快速傅里叶变换(FFT)相关器(8 bit数据)的1/10.

Study on 1 bit Correlator for the Image Integration of Space Solar Telescope

In the space solar telescope(SST),the image integration method is used to increase signal-to-noise ratio(SNR)of the solar magnetic field images.In the image integration,the conventional correlator based on image intensity can't simultaneously satisfy the real-time and low resources consumption in spatial mission.This paper proposes a 1 bit correlator to accomplish fast image correlation.Replacing usual multiplication by XOR Boolean operation,the 1 bit correlation algorithm can both accelerate the computation and reduce the complexity of hardware.Oriented to the solar granulation images,this paper presents the algorithm and the FPGA+DSP implementation in detail.The experimental results demonstrate that the 1 bit correlator satisfies well the computation precision and time requrements of image integration in the SST,and its FPGA resource consumption is only 1/10 of that of FFT-based(8 bit data)correlator.