针对太阳磁场望远镜(SMFT)终端海量图像数据的传输与处理等问题,设计并实现了基于达芬奇技术的嵌入式实时图像处理系统。利用UML建模抽象出核心对象,描述整个系统的行为并指导系统的设计。系统硬件上围绕双核(ARM+DSP)达芬奇处理器DM6446进行了设计和实现;系统软件上对ARM端的Monta Vista Linux操作系统和DSP端的DSP/BIOS嵌入式实时操作系统进行了客制化裁减和BSP开发;用户软件上设计并实现了一系列图像处理和识别功能,包括CMOS图像传感器成像控制、图像预览、图像预处理、太阳磁图实时提取、太阳图像FITS文件的生成、文件格式转换和数据压缩等。良好地满足了(SMFT)终端实时采集与图像处理的要求,提高了望远镜的观测效率。
This paper summarizes current helicity measurements in the solar active regions (ARs). There is a basic agreement with the "hemispheric sign rule (HSR)" of the current helicity among different vector magnetographs through two solar cycles, but there is a large dispersion of the fraction of ARs following the HSR. In our sample, there are 50%-78% ARs in solar cycle 22 and 44%-79% ARs in cycle 23 following the HSR. A variation is also found in the fraction of the ARs following the HSR between different instruments even when the same ARs are selected. The difference also exists for the same instrument when the selected ARs are different. There are some differences in the variation of HSR with solar cycle for the individual helicity parameter inferred from different instruments. Factors which influence the correlation of different data sets are analyzed.
In this paper, we study the correlation between the expansion speed of two-ribbon flares and the magnetic field measured in the ribbon location, and compare such correlation for two events with different magnetic configurations. These two events are: an M1.0 flare in the quiet sun on September 12, 2000 and an X2.3 flare in Active Region NOAA 9415 on April 10, 2001. The magnetic configuration of the M1.0 flare is simple, while that of X2.3 event is complex. We have derived a power-law correlation between the ribbon expansion speed (V r) and the longitudinal magnetic field (Bz) with an empirical relationship V r = A×Bz-δ, where A is a constant and δ is the index of the power-law correlation. We have found that δ for the M1.0 flare in the simple magnetic configuration is larger than that for the X2.3 flare in the complex magnetic configuration.
The data provider system has to provide users with reliable, constant and timely data information, and it has to guarantee further developments of new data applications. We develop a data provider system of hierarchical architecture with components, interactions and relationships in each layer. The system enables each layer to act in concert with each other without restrictions. It contributes to implementing the goal. The main frame of the data provider system has already been successfully implemented, the others of each layer are on the way according to the architecture.
