ASO-S/HXI太阳指向镜算法研究  

Research on the Solar Aspect System Algorithm of ASO-S/HXI

作　　者：喻福 苏杨 张哲 黄宇[1,2,3] YU Fu;SU Yang;ZHANG Zhe;HUANG Yu(Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026;Key Laboratory for Dark Matter and Space Astronomy,Chinese Academy of Sciences,Nanjing 210023)

机构地区：[1]中国科学院紫金山天文台,南京210023 [2]中国科学技术大学天文与空间科学学院,合肥230026 [3]中国科学院暗物质与空间天文重点实验室,南京210023

出　　处：《天文学报》2020年第4期77-87,共11页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(U1631242,U1731241,11820101002,11427803);中国科学院空间科学战略性先导科技专项(XDA15320300,XDA15320104,XDA15052200);江苏双创计划资助。

摘　　要：硬X射线成像是研究太阳耀斑等爆发现象的重要手段.由于采用调制成像而非直接成像的原因,X射线图像在日面上的位置需要借助太阳指向镜提供的仪器指向的日面坐标来确定.因此,指向信息对于耀斑定位实现多波段研究,理解太阳耀斑的物理过程具有重要的科学意义.在此对两种太阳指向镜指向信息的获取算法进行了测试.结合太阳指向镜的设计方案,首先利用SDO(Solar Dynamics Observatory)/AIA(Atmospheric Imaging Assembly)4500?的数据产生测试图像,其次对其进行二值化处理,分别提取日面轮廓和4个边角指定区域面积;最后分别利用最小二乘法和四象限法对太阳中心坐标进行反演.初步结果显示最小二乘法受随机噪声影响小,定位精度相对稳定约为0.25′′,并可提供四象限法解算的初值;后者的精度可以优于0.14′′,但受随机噪声影响较大.两种算法的精度都显著优于硬X射线成像仪(Hard X-ray Imager,HXI)太阳指向镜的设计要求,可为指向数据在将来科学分析中的实际应用提供参考.In this paper,we test two methods for obtaining the coordinate of the solar disk center for the Hard X-ray Imager(HXI),one of the three payloads onboard the Advanced Space-based Solar Observatory(ASO-S)satellite.HXI is an important means to study solar flares and other eruptions.However,due to the modulation-based indirect imaging rather than direct imaging,the position of the X-ray source on the solar disk should be determined by the coordinate of the solar disk pointed by the instrument which is provided by the solar aspect system.Therefore,the solar aspect information is of great scientific significance for the location of solar flares and the realization of multi-wavelength research to understand the physical processes of solarflares.Combined with the design scheme of the solar aspect system,a test image isfirst generated from the data of SDO(Solar Dynamics Observatory)/AIA(Atmospheric Imaging Assembly)4500?.Then,the binarization processing is used to obtain the solar limb and the specified area of four corners.Finally,the least square method and the four quadrant method are used to calculate the coordinates of the disk center.The preliminary results show that the least square method has a relatively stable accuracy of about 0.25 arcsec,which is less affected by random noise,and can be used as the initial values for the four quadrant method.The accuracy of the latter can be better than0.14 arcsec,but it is easily affected by random noise.The accuracies of both algorithms are significantly better than the design requirement of the solar aspect system in HXI,which can provide reference for the practical application of solar aspect data in future scientific analysis.

关 键 词：仪器:太阳指向镜 计算方法:四象限法 计算方法:最小二乘法 

分 类 号：P111[天文地球—天文学]