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在紫金山天文台13.7米望远镜22GHz系统的基础上,建立了22GHz太阳高时间分辨率的观测系统。本文介绍了在原系统基础上改造的波束/负载调制器和双温定标系统,以及为实现高时间分辨率而专门研制的QJ-2AG高速后端和独立的微机数据采集系统。投入使用的22GHz太阳高时间分辨率观测系统在时间分辨率为10ms时,灵敏度为0.02sfu,系统增益稳定性在全功率方式下为0.8%/30分钟,数据丢失率小于1 相似文献
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随着太阳射电理论研究的深入进展,高精度观测的必要性成为迫切的问题。对时间分辨率和频率分辨率提出了新的要求。我们提出了一种方案,可以在有限经费的条件下达到较好的性能,指标如下:250kHz谱分辨率和10ms时间分辨率。为了得到好的性能价格比,我们采用了ALTOS型微机,这将带来一些特别的困难。这篇文章的目的是讨论研制该仪器的天文背景和方案。 相似文献
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太阳二十二周峰年云南天文台四波段射电同步观测结果 总被引:1,自引:1,他引:0
本文主要介绍云南天文台“四波段太阳射电高时间分辨率同步观测系统”1989年12月至1993年4月观测事件的统计结果,对102个射电爆发进行了初步分析,着重揭示几个类别典型事件的时间轮廓,说明射电高时间分辨率观测的意义。 相似文献
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时间数字转换器TDC,作为一种高分辨率的时间间隔测量设备,广泛应用于现代电子系统。基于可编程逻辑门阵列FPGA实现时间数字转换器,具有灵活稳定、高速度、低成本的特点,成为了目前研制时间间隔测量计数器的热门方案。采用该方法实现时间数字转换器,其设计分辨率是由内部的加法进位链决定的。如何对FPGA中实现的加法进位链的布局布线进行优化,就成为决定时间数字转换器设计分辨率的关键问题。文章采用阿尔特拉(Altera)公司的FPGA器件实现时间数字转换器,使用Quartus II软件进行布局布线设计,并针对上述问题在开发过程中提出解决方法。同时根据Quartus II开发软件的不同版本,分别提出相应软件的布局布线优化方法。测试表明,通过对进位链的布局布线进行优化可以实现100.3 ps测量分辨率的时间数字转换器。 相似文献
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在声光频谱仪的中频输入端输入一个梳状讯号,分析输出的频谱,可以测定声光频谱仪的谱分辨率、频谱漂移等重要工作参数.这是进行谱线天文观测前必做的准备工作.我们对紫金山天文台用于13mm星际水脉泽观测的高频率分辨率的AOS-Ⅰ进行了仔细的频谱工作性能测定,结果发现它有良好的性能:平均通道间隔12.10±0.02kHz,平均谱分辨率221±1.8kHz,谱分辨率随时间变化1.0kHz/天,通带内谱分辨率起伏上1.0kHz,总工作带宽12.39MHz. 相似文献
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用云南天文台高时间分辨率(10ms)高频率分辨率(0.5MHz)的射电频谱仪观测分析证认了米波窄带短持续时间快频漂爆发的存在.这种爆发既不同于经典的III型爆发,也不同于spike和I型爆发,是一种新的米波爆发型别.它的特性与分米波的“blips”相近. 相似文献
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Keizo Nishi 《Solar physics》1975,42(1):37-42
The absolute intensity of the solar spectrum between 1550 Å and 1950 Å was measured photoelectrically by a rocketborne spectrometer flown from the Kagoshima Space Centre on 19 February 1973. The spectrometer was a single dispersive type with uniaxial Sun-pointer, and the absolute intensity from the whole disk with a 78 Å spectral resolution was measured. The result was consistent with our previous observation. 相似文献
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Hui-Rong Ji Qi-Jun Pu Yi-Hua Yan Yu-Ying Liu Zhi-Jun Chen Cheng-Ming Tan Cong-Ling Cheng De-Bang Lao Shu-Ke Li Zhi-Qiang Wang Min-Hong Yu Jian-Nong Liu Li-Kang Zhang Ji-Yong Gao National Astronomical Observatories Chinese Academy of Sciences Beijing Hebei Semiconductor Research Institute Shijiazhuang 《中国天文和天体物理学报》2005,5(4):433-441
An improved Solar Radio Spectrometer working at 1.10-2.06 GHz with much improved spectral and temporal resolution, has been accomplished by the National Astronomical Observatories and Hebei Semiconductor Research Institute, based on an old spectrometer at 1-2 GHz. The new spectrometer has a spectral resolution of 4 MHz and a temporal resolution of 5ms, with an instantaneous detectable range from 0.02 to 10 times of the quiet Sun flux. It can measure both left and right circular polarization with an accuracy of 10% in degree of polarization. Some results of preliminary observations that could not be recorded by the old spectrometer at 1-2 GHz are presented. 相似文献
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Jarken Esimbek 《中国天文和天体物理学报》2005,5(5):557-562
A maser spectral line system is newly implemented on the Urumqi 25m Radio Telescope. The system consists mainly of a cooling receiver and a 4096 channels digital correlation spectrometer. The frequency resolution of the spectrometer at the maximum signal bandwidth of 80MHz is 19.5kHz. After careful calibrations observation at the 1665 MHz OH maser emission was made towards a number of sources, including W49N and W75N. The observed results demonstrate that the digital correlation spectrometer is suitable for astronomical spectral line observations. 相似文献
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Xu Fu-Ying Xu Zhi-Cai Huang Guang-Ii Yao Qi-Jun Meng Xuan Wu Hong-Ao 《Solar physics》2003,216(1-2):273-284
A broadband solar radio spectrometer with a bandwidth of about 7 GHz has been developed in China for solar maximum 23. This
work is a cooperative project of Beijing Astronomical Observatory (BAO), Purple Mountain Observatory (PMO), Yunnan Observatory
(YNO), and Nanjing University. The spectrometer of PMO worked in the waveband of 4.5–7.5 GHz, that of BAO in 1–2 GHz, 2.6–3.8 GHz,
and 5.2–7.6 GHz, and that of YNO in 0.7–1.5 GHz. The spectrometer of PMO is a multichannel and frequency-agile one with a
time resolution of 1–5 ms and a frequency resolution of 10 MHz. It started to operate in August 1999 and since then more than
300 spectral events have been observed, and some type III or type III-like structures have also been found. In this paper,
some selected typical events, for example, the events on 25 August 1999 and 27 October 1999, are presented, and some new observed
features are also described and discussed. 相似文献
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Stuart Bowyer Eric J. Korpela Jerry Edelstein Michael Lampton Carmen Morales Juan Pérez-Mercader José F. Gómez JoaquÍn Trapero 《Astrophysics and Space Science》2001,276(1):155-161
Data obtained with a high resolution, high sensitivity spectrometer flown on the Spanish MINISAT 01 satellite wereused to test the Sciama model of radiatively decaying massive neutrinos. The observed emission is far less intense than that expected in the Sciama model. 相似文献
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先进天基太阳天文台卫星(Advanced Space-based Solar Observatory, ASO-S)是中国科学院第2批空间科学先导专项之一,其主要目标是同时观测太阳磁场、耀斑和日冕物质抛射,并对3者之间的相互关系和内在联系进行研究.硬X射线成像仪(HXI)是ASOS卫星的3大载荷之一,它通过对太阳活动发射的硬X射线进行傅里叶调制成像,实现高空间分辨率和高时间分辨率的太阳能谱成像观测.量能器单机是HXI的关键单机之一,其主要任务是精准测量通过每对光栅后太阳硬X射线的能量和通量.主要介绍了量能器单机的工作原理及其关键指标要求、标定设备及标定方案,最后给出了标定结果,从而验证了量能器单机方案设计的合理性. 相似文献
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总结了近期用射电频谱仪(高时间和高频谱分辨)和野边山射电日像仪(高空间分辨)以及国内外其它空间和地面设备分析日冕磁场和重联的系列工作。主要结论可归纳为:1)在Dulk等人(1982)的近似下自恰计算射电爆发源区磁场的平行和垂直分量,并首次得到该磁场在日面的两雏分布。2)为了考虑非热电子低能截止的影响,必须采用更严格的回旋同步辐射理论来计算。结果表明:低能截止和日冕磁场对计算有明显的影响,而其它参数(包括背景温度、密度、高能截止和辐射方向)的影响均可忽略。因此,对低能截止和日冕磁场必须联立求解。3)射电爆发中的精细结构可能反映了射电爆发源比较靠近粒子加速(磁场重联)的区域,利用高时间和高频率分辨的频谱仪和高空间分辨的日像仪联合分析,可以确定精细结构的源区位置,从而确定粒子加速(磁场重联)的准确时间和地点。 相似文献
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In this paper, we present the design of a high resolution Chirp Transform Spectrometer (CTS) which is part of the GREAT (German
REceiver for Astronomy at Terahertz frequencies) instrument onboard SOFIA, the Stratospheric Observatory For Infrared Astronomy.
The new spectrometer will provide unique spectral resolving power and linearity response, since the analog Fourier transform
performed by the CTS spectrometer was improved through a new design, that we call “Adaptive Digital Chirp Processor (ADCP)”.
The principle behind the ADCP consists on digitally generating the dispersive signal which adapts to the compressor dispersive
properties, achieving maximum spectral resolution and higher dynamic range. Excellent test results have been obtained such
as a white noise dynamic range of 30 dB, and a spectral resolution (FWHM) of 41.68 kHz which would mean if analyzing signals
with the high frequency band receiver on the GREAT instrument (4.7 THz) a spectral resolving power (λ/Δ λ) higher than 108. 相似文献