内外参数精确建模的太阳敏感器标定     

樊巧云  张广军  魏新国 《地理研究》2011,37(9)

对数字式太阳敏感器标定,现有的多项式拟合和只有内部参数的简单建模方法标定精度低,为提高标定精度,提出一种基于内外参数精确建模的标定方法．通过分析太阳敏感器标定系统的内外参数,建立太阳敏感器标定模型,基于太阳模拟器和两轴转台获取标定点数据,采用最小二乘法分两步优化得到各模型参数．该方法不需要太阳光线与太阳敏感器成像面的初始对准,操作方便,同时通过精确分离太阳敏感器内外参数,避免了标定系统外部参数误差对太阳敏感器内部参数标定的影响,且通过两步优化,进一步提高了太阳敏感器的标定精度．实验结果表明：该方法的标定精度达0．005°（±60°视场）,比常用的标定方法的标定精度（0．02°）提高约4倍．  相似文献   

Analysis of the Properties of Super Solar Proton Events and Associated Phenomena     

CHENG Li-bin  LE Gui-ming  LU Yang-ping  CHEN Min-hao  LI Peng  YIN Zhi-qiang 《Chinese Astronomy and Astrophysics》2014

The solar flares, the speeds of shocks propagated in the solar-terrestrial space and driven by coronal mass ejections (CMEs), the heliographic longitudes and Carrington longitudes of source regions, and the geomagnetic storms, which are accompanied by the super solar proton events with a peak ?ux equal to or exceeding 10 000 pfu, have been studied by using the data of ground-based and space observations. The results show that the heliographic longitudes of source regions of super solar proton events distributed in the range from E30? to W75°. The Carrington longitudes of source regions of super solar proton events distributed in the two longitudinal belts, 130°∼220° and 260°∼320°, respectively. All super solar proton events were accompanied by major solar flares and fast CMEs. The averaged speeds of shocks propagated from the sun to the Earth were greater than 1 200 km/s. Eight super solar proton events were followed by major geomagnetic storms (Dst≤−100 nT), except that one super solar proton event was followed by a geomagnetic storm with the geomagnetic activity index Dst=−96 nT, a little smaller than that of major geomagnetic storms.  相似文献   

A Study on the CdZnTe Array Detector     

CAI Ming-sheng  GUO Jian-hua  XIE Ming-gang  ZHENG Chun-xiao 《Chinese Astronomy and Astrophysics》2014

The CdZnTe array detector is a new type of semiconductor detector being rapidly developed in recent years. It possesses a high spatial resolution and a high energy resolution, and it can work at room temperatures. This paper describes the physical properties and working principle of the CdZnTe array detector, as well as the manufacturing technology, including the chip pretreatment, passivation, ohmic electrode preparation, array template selection, and array packaging technology (micro-interconnection). For evaluating the perfor-mance of the detector, the authors have developed successfully a 4 pixel×4 pixel CdZnTe array and an 8 pixel×8 pixel CdZnTe array (with the thicknesses of 5 mm and 2 mm, the pixel size of 2 mm×2 mm, and the gaps of 0.15 mm and 0.2 mm, respectively) in cooperation with the partner. A multi-channel electronic readout system based on the ASIC (Application Specific Integrated Circuit) chip is devel-oped independently for the charge measurement of the 4 pixel×4 pixel CdZnTe array. The energy spectra and corresponding energy resolutions of the 16 pixels are obtained with the ¹³⁷Cs radiative source, among them the best resolution is 4.8%@662 kev.  相似文献   

A Statistical Study of the Relation between the Amplitude of Solar Cycle and the Area of Active Regions     

LI Peng  LE Gui-ming  CHEN Yu-lin  CHEN Min-hao  LU Yang-ping  YIN Zhi-qiang 《Chinese Astronomy and Astrophysics》2014

Based on the observational data of sunspots, the relation between the amplitude of solar cycle and the total area of all active regions occurred in a solar cycle has been investigated. The result shows that the amplitude of solar cycle has a good correlation with the total area of all active regions occurred in the solar cycle. The relation between the amplitude of solar cycle and the area of the largest active region during a solar cycle has also been investigated. The result shows that the amplitude of solar cycle has a poor correlation with the area of the largest active region during a solar cycle, and there is no fixed relation between the peak time of a solar cycle and the time when the largest active region occurred in the solar cycle.  相似文献   

太阳日冕物质抛射特性的模糊分类研究   总被引：1，自引：0，他引：1  

韩正忠  唐玉华 《天文学报》2002,43(4):359-365

应用模糊集理论对日冕物质抛射（CME）特性进行分类研究，根据CME形态特性和特征因子之间的关系，重点阐明构造每个特性的隶属函数和确定权重因子的基本原理与方法，通过数据处理，对CME特性进行聚类分析，结果表明，模糊分类方法要优于传统的统计分析，对于CME特性按重要性分类，为空间环境的预报提供了一个具有实用价值的方法。  相似文献   

Vector Magnetic Field Measurement of NOAA AR 10197     

Hong-Fei Liang  Hai-Juan Zhao  Fu-Yuan Xiang National Astronomical Observatories / Yunnan Observatory  Chinese Academy of Sciences  Kunming  Graduate School of Chinese Academy of Sciences  Beijing Yunnan Normal University  Kunming National Satellite Meteorological Center  China Meteorological Administration  Beijing Xiangtan University  Xiangtan 《中国天文和天体物理学报》2006,6(4):470-476

A set of two-dimensional Stokes spectral data of NOAA AR 10197 obtained by the Solar Stokes Spectral Telescope (S3T) at the Yunnan Observatory are qualitatively analyzed. The three components of the vector magnetic field, the strength H, inclinationγand azimuth X, are derived. Based on the three components, we contour the distributions of the longitudinal magnetic field and transverse magnetic field. The active region (AR) has two different magnetic polarities apparent in the longitudinal magnetic map due to projection effect. There is a basic agreement on the longitudinal magnetic fields between the S3T and SOHO/MDI magnetograms, with a correlation coefficientρBl = 0.911. The transverse magnetic field of the AR has a radial distribution from a center located in the southwest of the AR. It is also found that the transverse magnetic fields obtained by Huairou Solar Observing Station (HRSOS) have a similar radial distribution. The distributions of transverse magnetic field obtained by S3T and HRSOS have correlation coefficients,ρAzimu = 0.86 andρBt = 0.883, in regard to the azimuthal angle and intensity.  相似文献   

2002年7月23日X射线耀斑的RHESSI和TRACE观测物理图像     

李友平  甘为群 《天文学报》2004,45(2):158-167

通过对比分析TRACE195A和RHESSI的X射线及Ha的图像，发现2002年7月23日的X4.8级耀斑的主体是一个典型的双带耀斑，它的Ha及TRACE195A的图像都显现出明显的双带耀斑特征，TRACE195A的像还呈现一个环拱结构，其环拱的足点与TRACE的亮带并不重合，但TRACE的亮带与X射线像的位置对应很好．在耀斑极大时刻附近，大于38keV的X射线像呈现一个低的环跨在TRACE的双带上，X射线环的顶点及两足点尤其明显，在这个低的环上方，还存在一个在低能量段明显的X射线日冕源，对该耀斑的空间结构及演化特征作了描述，还简单地讨论了一个可能的理论解释．  相似文献   

Robert E. Horton's perceptual model of infiltration processes     

Keith Beven 《水文研究》2004,18(17):3447-3460

Robert E. Horton is best known as the originator of the infiltration excess overland flow concept for storm hydrograph analysis and prediction, which, in conjunction with the unit hydrograph concept, provided the foundation for engineering hydrology for several decades. Although these concepts, at least in their simplest form, have been largely superseded, a study of Horton's archived scientific papers reveals that his perceptual model of infiltration processes and appreciation of scale problems in modelling were far more sophisticated and complete than normally presented in hydrological texts. His understanding of surface controls on infiltration remain relevant today. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

A hybrid simulation study of magnetic reconnection in anisotropic plasmas     

Guo Jun  Li Yi  Lu Quan-ming  Wang Shui 《Chinese Astronomy and Astrophysics》2003,27(4):374-382

The process of magnetic reconnection in anisotropic plasmas is studied numerically using a 2-dimensional, 3-component hybrid simulation. The results of the calculation show that, when the plasma pressure in the direction perpendicular to magnetic field is larger than that in the parallel direction (e.g. P/P = 1.5), instability may greatly increase, speeding up the rate of reconnection. When P is smaller than P, (e.g., when P/P = 0.6), fire hose instability appears, which will restrain the tearing mode instability and the process of magnetic reconnection.  相似文献   

Observation of a type of sporadic solar mass ejection and its physical interpretation with numerical simulation     

Zhang Yan-an  Song Mu-tao  Ji Hai-sheng  Huang Guang-li   《Chinese Astronomy and Astrophysics》2003,27(4):409-425

Seven mediated and small ejective events on the sun observed at Ganyu Observing Station of Purple Mountain Observatory in 2000 are investigated. It is found that they were not accompanied by brightening. Their lengths were in the range 1–2.5×10⁴ km, their widths, 3–5×10³ km, and their lifetimes, 3–7 minutes. They were produced at places of weak magnetic fields and far away from large sunspots. These ejections are interpreted by numerical simulation with 1-D hydrodynamic equations of flow along magnetic arcs. As demonstrated by the results, they are different from the spicules and surges simulated by Suematsu et al. and Shibata et al. They are not matter with photospheric or chromospheric densities pushed by shock waves or rebound shock waves toward the solar corona, rather, they are ejections formed by continuous matter flows after magnetic reconnection. After evolving for about 5 minutes, they can attain a stationary hydrodynamic state.  相似文献