CINRAD/SA雷达伺服电机连续故障诊断分析   总被引：1，自引：0，他引：1  

吴昌叨  刘光普  任雍  汪学渊 《气象科技》2016,44(1):164-166

CINRAD/SA天气雷达投入业务运行以来,在天线伺服系统方面出现了很多次故障,而直流方位电机是天线伺服系统的主要组成部分也是发生故障较多的部件之一。2014年福建长乐CINRAD/SA天气雷达在重大天气保障过程中,连续发生方位电机卡死造成雷达停机和测速机性能降低引起天线转速不稳造成雷达产品异常的故障;根据天线控制信号流程,通过运行雷达RDASOT测试程序、测量直流方位电机阻值、测量测速机反馈电压等方法,分析其故障的成因,对雷达伺服直流电机故障分析及解决方法有重要的指导作用。  相似文献   

Evaluation of regional climate simulations over the CORDEX-EA-II domain using the COSMO-CLM model     

Weidan Zhou  Jianping Tang  Xueyuan Wang  Shuyu Wang  Xiaorui Niu  Yuan Wang 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(2):107-127

The COSMO-CLM (CCLM) model is applied to perform regional climate simulation over the second phase of CORDEX-East Asia (CORDEX-EA-II) domain in this study. Driven by the ERAInterim reanalysis data, the model was integrated from 1988 to 2010 with a high resolution of 0.22°. The model’s ability to reproduce mean climatology and climatic extremes is evaluated based on various aspects. The CCLM model is capable of capturing the basic features of the East Asia climate, including the seasonal mean patterns, interannual variations, annual cycles and climate extreme indices for both surface air temperature and precipitation. Some biases are evident in certain areas and seasons. Warm and wet biases appear in the arid and semi-arid areas over the northwestern and northern parts of the domain. The simulated climate over the Tibetan Plateau is colder and wetter than the observations, while South China, East China, and India are drier. The model biases may be caused by the simulated anticyclonic and cyclonic biases in low-level circulations, the simulated water vapor content biases, and the inadequate physical parameterizations in the CCLM model. A parallel 0.44° simulation is conducted and the comparison results show some added value introduced by the higher resolution 0.22° simulation. As a result, the CCLM model could be an adequate member for the next stage of the CORDEX-EA project, while further studies should be encouraged.  相似文献   

Search for narrow energy‐shifted lines in AGN spectra in the XMMNewton archive     

A. L. Longinotti  S. Bianchi  M. Guainazzi  J. Roa  M. Santos‐Lleo 《Astronomische Nachrichten》2006,327(10):1020-1023

Thanks to the large effective area and the spectral resolution of current X‐ray satellites, the detection of X‐ray narrow spectral features in the 5–7 keV band is becoming commonplace in many AGN observations. Such lines, both in emission and in absorption, are mostly interpreted as arising from Iron atoms. When observed with some displacement from their rest frame position, these lines carry the potential to study the motion of circumnuclear gas in AGN, providing a diagnostic of the effects of the gravitational field of the central black hole. These narrow features have been often found with marginal statistical significance. A systematic search for narrow features in type1 AGN is being performed on all spectra available in the XMM‐Newton archive with the aim to estimate the significance of the features with Monte Carlo simulations of synthetic spectra. The project and preliminary results are presented. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Multi-timescale variation of East Asian winter monsoon intensity and its relation with sea surface temperature during last millennium based on ECHO-G simulation   总被引：1，自引：0，他引：1  

Kuang Xueyuan  Liu Jian  Zhang Yaocun  Huang Danqing  Huang Ying 《Asia-Pacific Journal of Atmospheric Sciences》2011,47(5):485-495

Based on the simulation results derived from ECHO-G global coupled climate model, several East Asian winter monsoon (EAWM) indices are compared in order to choose the most suitable one for signaling the intensity of winter monsoon in the last millennium. The index I_shi, which is defined with normalized sea level pressure difference between sea and land in mid and low latitudes, is selected to describe the winter monsoon intensity variation owing to its better capability for reflecting the variation of winter monsoon subsystems, such as the continental high pressure, Aleutian low, East Asian major trough, westerly jet stream, and surface air temperature than the other indices examined. Wavelet analysis on index I_shi shows that the EAWM intensity is characterized by multi-timescale variation with inter-annual, decadal, inter-decadal and inter-centennial oscillations on the background of a slight descending trend. Correlation analysis between the EAWM index and sea surface temperature (SST) at various timescales reveals that the SST in mid-latitudes might provide the background of the EAWM strength changes above decadal timescales, and a negative-feedback process lasting for about two years is found between the EAWM intensity and the SST in the eastern equatorial Pacific. According to the correlation, the El Nino occurrence in the second-half of the year leads to weaker EAWM than normal in the following winter and the weakened EAWM corresponds to lower SST in eastern equatorial Pacific after about half a year, which will then strengthen the EAWM intensity in the next winter. It is a stable feedback process and its mechanism is discussed.  相似文献   

冰雷达探测数据处理方法研究——以南极冰盖Dome A地区的数据处理为例   总被引：1，自引：0，他引：1       下载免费PDF全文

王甜甜  孙波  关泽群  崔祥斌  冯甜甜  唐学远  张栋  陈昀 《极地研究》2013,25(2):197-204

提出了冰雷达数据处理的流程,详细论述了冰雷达数据处理中常规修正的关键技术：静态校正、增益控制、带通滤波以及偏移处理等。以中国第24次南极科学考察（CHINARE 24）所获取的Dome A 地区30 km×30 km范围冰雷达原始数据处理作为实例,提取得到了该区域冰盖内部等时层埋深以及冰盖的冰厚数据。通过插值展现了冰盖等时层以及冰岩界面的三维空间形态。结合该区域ICESat冰盖表面高程数据,构建出了Dome A地区涵盖冰盖表面、冰盖等时层以及冰岩界面形态特征的三维模型。  相似文献   

Dome Argus： Ideal site for deep ice drilling     

TANG Xueyuan  SUN Bo  LI Yuansheng  LI Xin  CUI Xiangbin 《极地研究(英文版)》2012,23(1):47-54

Located on the centre of ice drainage range, the highest Dome Argus （Dome A） of East Antarctic Ice Sheet （EAIS）, could be represented as an ideal site for deep ice cores drilling containing oldest paleo-climate records. To select a suitable drilling site for deep ice core, it needs gather all information pertaining to the local meteorology, ice sheet landforms, ice thickness, subgla- cial topography of bed rocks, ice velocity, internal structures of ice sheet, etc. Based on the International Partnerships in Ice Core Sciences （IPICS）, we present recent achievement of glaciological research and its perspective at Dome A in this paper. We system- atically discussed the merits and possible ventures of potential drilling sites around Dome A. Among all the candidates, we find that the Chinese Antarctic Kunlun Station is the best site for and assess further the possibility to obtain a replicate core for carrying out the first deep ice core drilling campaign. We emphasize studying dynamics and evolution of climate change.  相似文献   

矿山开发要素空间拓扑关系的判定与应用     

李学渊  陈时磊  边凯 《测绘通报》2015,(3):49-52

针对矿山开发秩序混乱的问题, 通过描述矿山开发要素与采矿权的空间位置关系, 介绍和设计了点面、面面拓扑关系的判定及矿山开发秩序的检验;以2010年QuickBird遥感影像为数据源, 对宁武矿区进行了矿山监测, 基于空间数据库引擎和嵌入式GIS组件, 实现了矿山开发要素的空间拓扑关系判定和查询, 为矿山监测提供了有效的参考信息。  相似文献   

对流层上层东半球副热带西风急流与副热带(南亚)高压的关系   总被引：7，自引：4，他引：3  

刘杰  况雪源  张耀存 《气象科学》2010,30(1):34-41

用NCEP/NCAR月平均再分析资料对南亚高压和对流层上层西风急流的季节变化及盛夏两类型态进行对比。结果表明,南亚高压和西风急流中心都有从冬到夏的西移北进和从夏到冬的东退南撤,急流中心位于南亚高压中心北侧。东亚夏季风盛行期间南亚高压中心的北移提前于西风急流中心的北移,二者的强度呈反相的季节变化。一般情况下,伊朗高压对应西部急流型,青藏高压对应东部急流型。典型东、西部急流年份中高纬气温及高度场的差异表明气压梯度力强弱对比是急流东西型变化的主要原因,南亚高压的位置基本上决定了急流中心的型态,但由于南亚高压具有"趋热性",而急流的移动符合热成风的规律,因而二者的热力影响机制有所不同。  相似文献   

多传感器组合导航系统的两级分布式融合算法研究     

林雪原 《武汉大学学报(信息科学版)》2012,37(3):274-277

研究了可用于多传感器组合导航系统的两级分布式最优融合算法,以理论的形式证明了在有、无信息反馈的情况下最终的融合结果是等价的与最优的。仿真结果在验证上述理论的情况下,也说明了来自融合中心的反馈信息可明显提高子滤波的滤波性能。  相似文献   

一种异步多传感器组合导航系统融合算法     

林雪原 《武汉大学学报(信息科学版)》2012,37(1):54-57,67

针对不同导航传感器存在的采样率不同步（或尺度不同）,提出了一种基于状态方程多尺度变换的异步多传感器组合导航系统信息融合算法。仿真结果表明,本算法不仅具有较好的实时性,而且具有较好的融合精度。  相似文献