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1.
基于MYSQL/LINUX 的LAMOST数据库设计与实现   总被引:1,自引:0,他引:1  
大天区面积多目标光纤光谱天文望远镜(LAMOST)将被建成,在投入使用之前设计开发出全自动处理光谱的软件系统是必需的。完善的数据库系统是该光谱处理软件不可缺少的一部分。本文分析了LAMOST对数据库的需求,设计并实现了基于MYSQL/LINUX的LAMOST数据库系统并对该系统进行了初步测试。  相似文献   

2.
本文详细介绍了1983年日食光谱资料的强度和高度定标方法和结果,并讨论了其精度.对同一波段,用两种不同的绝对定标方法得出的结果基本一致,说明定标是可靠的.文中还给出了二切无缝谱色球底的位置,并计算了该区的温度.  相似文献   

3.
大天区面积多目标光纤光谱天文望远镜(LAMOST)将被建成,会产生大量的星系光谱数据。根据天文数据的积累过程,我们设计基于数据仓库的星系光谱分类系统。文章首先介绍了星系光谱的特征,数据仓库的特点,在此基础上描述了建立基于数据仓库的星系光谱自动分类系统的步骤,并给出对该系统进行测试的结果。  相似文献   

4.
给出一种可用于大天区面积多目标光纤光谱天望远镜(LAMOST)的光纤定位系统,它将望远镜焦面板分成4000个小区域,每个区域中安装一个可控式光纤定位单元,光纤由单元带动作精确定位。本讨论了系统的组成及特点,该系统可望能成功应用于LAMOST项目中。  相似文献   

5.
我国预计2025年发射的巡天空间望远镜(Chinese Space Station Telescope, CSST),主要用于开展大规模的多色成像与无缝光谱巡天工作。发射前需要利用地基望远镜对空间望远镜的光学成像系统、探测器,以及设备长时间运行稳定性进行地面测试。设计了兴隆观测基地80 cm望远镜的无缝光谱地面测试,利用A型恒星、B型恒星和沃尔夫拉叶星HD4004的强吸收和发射线特征,拟合色散方程,并发现色散方程具有空间分布特征。对HR3173的53条数据的零级谱位置信息及色散方程系数进行了二次曲面拟合,并利用该曲面对HR3173零级像位置范围内的HR718数据进行了波长定标,得到的CCD上8×13 pixels范围内的平均视向速度精度为51 km/s。  相似文献   

6.
针对长焦距望远镜CCD观测天然卫星的情况,导出了用两颗亮星作为定标时,CCD视场几何参数(比例尺和指向)测量的误差公式,进而设计了多定标星定标时正确的归算方案。新方案不仅对天然卫星的位置测量,也对同类型的小视场CCD位置测量具有指导意义。  相似文献   

7.
大气折射对大视场多目标光纤光谱观测的影响   总被引:3,自引:0,他引:3  
大气折射从两个方面影响大视场多目标光纤光谱的观测:一是大气较差折射,二是由大气折射引起的大气色散。本定量地分析了这些影响。给出其对一具有5°视场,位于北纬40.4°的望远镜在不同纬度时影响的大小。  相似文献   

8.
探月光学有效载荷系统含CCD立体相机与干涉成像光谱仪两台光学遥感器,CCD立体相机完成的科学目标主要是与激光高度计配合获取月球表面三维立体图像。文章主要叙述了三线阵立体相机的工作原理,定标内容、目的以及CCD裸片像元检测和整机的相对定标和绝对定标过程。  相似文献   

9.
介绍一种天线口面温度定标的方法,当用这个方法对目标源进行温度定标时,由于定标源讯号和目标源讯号均由天线口面同路输入,因此波导和微波器件的传输损耗在定标的过程中被自动消除,因而这种温度定标方法能大大地提高观测资料的精度。目前天线口面温度定标方法除了在射电天和微波天线测量中应用外,还广泛应用于雷达和无线电技术测量及微波遥感控制等。  相似文献   

10.
大气折射从两个方面影响大视场多目标光纤光谱的观测:一是大气较差折射,二是由大气折射引起的大气色散.本文定量地分析了这些影响,给出其对一具有5°视场、位于北纬40.4°的望远镜在不同纬度时影响的大小.  相似文献   

11.
This paper describes the general characteristics of raw data from fiber‐fed spectrographs in general and fiber‐fed IFUs in particular. The different steps of the data reduction are presented, and the techniques used to address the unusual characteristics of these data are described in detail. These techniques have been implemented in a specialized software package, R3D, developed to reduce fiber‐based integral field spectroscopy (IFS) data. The package comprises a set of command‐line routines adapted for each of these steps, suitable for creating pipelines. The routines have been tested against simulations, and against real data from various integral field spectrographs (PMAS, PPAK, GMOS, VIMOS and INTEGRAL). Particular attention is paid to the treatment of cross‐talk. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

12.
Precise fiber positioning is crucial to a wide field,multi-fiber spectroscopic survey such as the Guoshoujing Telescope(the Large Sky Area Multi-Object Fiber Spectroscopic Telescope,LAMOST).Nowadays,most position error measurements are based on CCD photographic and image processing techniques.These methods only work for measuring errors orthogonal to the telescope optical axis,but there are also errors that lie parallel to the optical axis of the telescope,such as defocusing,and errors caused by the existing deviation angle between the optical axes of a fiber and the telescope.Directly measuring the two latter types of position errors is difficult for an individual fiber,especially during observations.Possible sources of fiber position errors are discussed in brief for LAMOST.By constructing a model of magnitude loss due to the fiber position error for a point source,we propose an indirect method to calculate both the total and systematic position errors for each individual fiber from spectral data.Restrictions and applications of this method are also discussed.  相似文献   

13.
Fiber – or intermediate drift – bursts are a continuum fine structure in some complex solar radio events. We present the analysis of such bursts in the X17 flare on 28 Oct. 2003. Based on the whistler wave model of fiber bursts we derive the 3D magnetic field structures that carry the radio sources in different stages of the event and obtain insight into the energy release evolution in the main flare phase, the related paths of nonthermal particle propagation in the corona, and the involved magnetic field structures. Additionally, we test the whistler wave model of fiber bursts for the meter and the decimeter wave range. Radio spectral data (Astrophysikalisches Institut Potsdam, Astronomical Observatory Ond?ejov) show a continuum with fibers for ≈?6 min during the main flare phase. Radio imaging data (Nançay Radio Heliograph) yield source centroid positions of the fibers at three frequencies in the spectrometer band. We compare the radio positions with the potential coronal magnetic field extrapolated from SOHO/MDI data. Given the detected source site configuration and evolution, and the change of the fiber burst frequency range with time, we can also extract those coronal flux tubes where the high-frequency fiber bursts are situated even without decimeter imaging data. To this aim we use a kinetic simulation of whistler wave growth in sample flux tubes modeled by selected potential field lines and a barometric density model. The whistler wave model of fiber bursts accurately explains the observations on 28 Oct. 2003. A laterally extended system of low coronal loops is found to guide the whistler waves. It connects several neighboring active regions including the flaring AR 10486. For varying source sites the fiber bursts are emitted at the fundamental mode of the plasma frequency over the whole range (1200?–?300 MHz). The present event can be understood without assuming two different generation mechanisms for meter and decimeter wave fiber bursts. It gives new insight into particle acceleration and propagation in the low flare and post-CME corona.  相似文献   

14.
基于Lomb算法的非等间距VLBI观测资料频谱分析研究   总被引:1,自引:0,他引:1  
研究非等间距采样频谱分析中所发生的虚假信号问题.利用Lomb非等间距频谱分析方法对准多周期采样的模拟资料和VLBI实测资料进行频谱分析,得出了准多周期采样会产生虚假谱峰的结论.通过对频谱特征的分析,给出了虚假谱峰的位置分布的经验公式并从统计学角度证明了该公式.利用该公式可以确认准多周期采样频谱分析中的虚假谱峰位置,同时对公式的具体应用进行了讨论.其结论是基于VLBI的观测资料采样特征得到的,但同样适用于一般的准多周期采样资料的频谱分析.  相似文献   

15.
李乡儒 《天文学进展》2012,30(1):94-105
特征提取是对光谱测量数据成分的分解、重组和选择的过程,它是光谱数据挖掘中的一个关键环节,不仅决定着后续处理的质量、效率、系统复杂度和稳健性,也关系到能够挖掘到什么知识和处理结果物理意义的可解释性。按照特征表达方式将已有方法分为3类:统计约简法,特征谱法和谱线法,并对这些方法的基本原理、适用性、优缺点及其在光谱数据挖掘中的应用作了综述和分析。另外,亦从方法的"时"、"频"分析能力方面探讨了不同方法的特点,例如,物理意义的易解释性、对波长定标畸变和流量定标畸变的敏感性等。  相似文献   

16.
The construction costs of distributed radio telescopes are to a great extent determined by the deployment costs of the fiber optic data transport network that is needed to transport the received information to the data processor(s). As such, the baseline and data rates that are feasible for a specified amount of money are determined by the status of the technology and deployment costs of the communication network. In this paper the present day data transport status is described and, using a costing model, the most attractive data transport technologies are determined, taking the LOFAR telescope (ASTRON, 2005) as an example. In the outlook, the near-term data transport technology developments are described.  相似文献   

17.
Based on data from the spectrographs of IZMIRAN and Tremsdorf station (Astronomical Institute, Potsdam), we analyze the ropes of narrow-band fibers in the spectra of solar radio bursts in the meter wave band by invoking events of satellite data (SOHO/LASCO, EIT, MDI) for the analysis. We consider in detail basic properties of the ropes in four events in comparison with previously known data. The fibers in ropes are more commonly observed with an overlap in time and frequency, but occasionally (more often at the end of the ropes) they can follow with a separation in time. The fiber duration and recurrence period seldom remain stable and, in general, increase from 0.3–0.5 s at the beginning to several seconds at the end of the rope. The relative values of the instantaneous and total fiber frequency bandwidths change only slightly in different events; δ f / f ≈ 0.003–0.005 and Δf / f ≈ 0.02–0.03. Most of the ropes exhibit a low-frequency absorption. The fibers in ropes are similar to ordinary intermediate drift bursts (fiber bursts), but they drift in a narrow frequency band and have a more frequent recurrence in some events. The ropes of fibers are usually observed in the time interval when the shock front catches up with the leading edge of a coronal mass ejection. Under the condition of a unified approach to interpreting the ropes of fibers in all events, their basic properties can be explained in terms of the model of fiber bursts. The connection of fibers with the developed zebra pattern is shown within the framework of a unified approach to the formation theory of stripes in emission and absorption in the model on whistlers.  相似文献   

18.
分析和比较了CSRH—Ⅱ(中国频谱日像仪二期工程,即厘米波段日像仪)的几种可行光传输方案(包括全频段适时模拟光传输,分频段分时模拟光传输,数字光传输等)的技术难度及性价比。对优选的分频段分时模拟光传输作了原理性电路设计及计算。  相似文献   

19.
Several recent phenomena with zebra patterns (ZPs) and fiber bursts on the dynamic spectra of solar type IV radio bursts have been complexly analyzed using all available ground-based and satellite data (SOHO, TRACE, RHESSI). ZPs and fiber bursts were observed at frequencies of 50–3800 MHz. The main relative spectral parameters and the degree of circular polarization of ZPs and fiber bursts are almost identical. The fine structure was observed in powerful and weak phenomena (and was more impressive in weak phenomena) during impulsive and decline phases at instants of recurring continuum bursts. The shape of the fine structure depends on that of the magnetic loops in a radio source, the type of fast particle acceleration (impulsive or prolonged), and the presence of shock waves and coronal mass ejections. Several new effects of the interaction between zebra stripes and fiber bursts have been detected. Specifically, up to 40 fiber bursts with different frequency ranges were simultaneously observed in the frequency range 1–2 GHz against a background of sudden absorptions. It has been indicated that different effects in the ZP stripe behavior can be explained within the scope of the model with whistlers, if the quasi-linear diffusion of fast particles on whistlers (which deforms the particle velocity distribution function) is taken into account.  相似文献   

20.
周爱华 《天文学报》1995,36(2):216-219
从微波爆发谱光薄部分辐射估计日冕磁场强度的一种方法周爱华(中国科学院紫金山天文台南京210008)关键词回旋同步加速辐射谱,磁场强度1引言目前对太阳活动区物理和耀斑物理过程的真正认识仍是十分困难的,原因之一在于迄今为止人们仍未找到一种完善的,能被大家...  相似文献   

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