CINRAD/SB发射机系统故障定位方法与技巧

总结了CINRAD/SB雷达发射机系统的高频脉冲整形、全固态调制器、回扫充电、充电校平和同步交流方波稳流灯丝电源等新技术的特点,详细介绍了CINRAD/SB发射机信号流程、同步信号特征、关键点波形和技术参数。对多年来CINRAD/SB雷达发射机系统出现的故障和报警信息进行了归类,分析了发射机系统电源、高频放大链、调制器、控制保护电路故障的定位方法和技巧,列举了高频放大链电路、回扫充电电路、同步信号时序电路典型故障的分析定位和处理结果,提出了CINRAD/SB雷达发射机系统定位方法与技巧,同时给出了发射机系统出现故障时所能采取的应急措施,以及对发射机故障定位、维修、维护等方面的建议,为新一代天气雷达提供技术支持和保障。     

CINRAD/SA雷达故障统计分析

对石家庄CINRAD/SA雷达运行1年的故障情况进行了统计分析。介绍了常见告警信息,故障现象及处理办法。通过对雷达开机日数、故障日数、损坏器件情况、故障发生部位、告警信息、以及与环境温度的相关性分析,认为CINRAD/SA雷达运行状态与网络保障、计算机状况、环境温度等环境因素密切相关。现场的运行环境对CINRAD/SA雷达的运行状况影响较大。CINRAD/SA雷达发射机和天线控制系统故障较多,是日常维护的重点。为保障雷达正常运行,加强CINRAD/SA雷达网络安全管理、采用高性能计算机、做好雷达维护工作、保障良好的机房环境非常重要。     

CINRAD/SA雷达高压故障组件级排查方法与典型个例分析

根据中国气象局探测中心对全国雷达2006—2015年的备件消耗评估和对全国CINRAD/SA雷达2007—2015年的故障归属进行统计发现,发射机故障率仅次于伺服系统,这与发射机长期处于高压强电的工作环境密切相关。发射机故障中,高压问题直接导致停机,严重影响观测,是比较难处理的一类故障。通过统计全国CINRAD/SA雷达发射机的高压故障归属与检修经验,结合相关组件的参数特征,梳理常见高压故障,归纳总结出CINRAD/SA雷达高压故障的排查方法,并从项目组收集的案例库中选取2个典型个例进行分析,为台站提供借鉴。     

基于故障树的CINRAD/SA雷达故障诊断系统

通过分析目前我国新一代天气雷达的维修保障现状,提出利用雷达故障诊断系统来辅助和代替传统的雷达故障诊断手段,以达到缩短故障维修时间、规范维修维护方法和提高维修效率的目的。论文以CINRAD/SA型号的天气雷达为对象,通过对CINRAD/SA天气雷达系统结构的深入研究,结合雷达现有的故障定位功能,确定了故障信息的采集方式;收集和分析了2002—2014年期间近70部CINRAD/SA雷达相对完整的故障维修案例,基于故障树分析法(FTA)建立了雷达故障树,并以发射机子系统为例,进行了故障树的定性分析和定量分析,得到初始数据。在分析和研究的基础上,开发了"CINRAD/SA天气雷达故障诊断系统",为雷达故障诊断提供指导思路。     

CINRAD/SA发射机典型故障分析处理

发射机是CINRAD/SA天气雷达的重要组成部分,长期处于连续高压强电的工作状态中,且线路复杂,是CINRAD/SA雷达中故障率较高的部分。以广州雷达为基础,结合其他部分台站的经验,整理出发射机在运行过程中出现的几个典型故障及其排除过程,总结这些故障形成的原因,并提出解决方法,对发射机的故障分4个方面进行了总结,此类经验及分析思路对雷达技术保障人员有一定的借鉴意义。     

CINRAD/SA雷达开关组件故障分析处理

根据广州CINRAD／SA雷达发射机开关组件的一起故障现象,结合信号流程、电路原理图,深入元件一级,对故障的定位、检测及排除过程作了详细介绍,并对故障的成因作了推断分析,最后就雷达维护方面总结了一些经验,旨在对雷达技术保障人员提供参考和借鉴。     

防城港雷达一次发射机故障的分析和处理

针对CINRAD/SA新一代天气雷达发射机某次特殊故障进行分析,总结出类似故障的处理方法及排障过程中应注意的事项。     

CINRAD/SA雷达发射机故障诊断技术与方法

济南CINRAD/SA天气雷达自2002年2月交付使用至2007年6月,雷达在工作中共出现大小硬件故障41次,其中发射机故障23次,占总故障的56%.分析了发射机故障的成因,并提出相应的排除方法和应对措施,旨在积累经验达到快速排除故障的目的.     

CINRAD/SA雷达发射机故障诊断和分析

通过对南宁CINRAD/SA天气雷达一次发射机故障检修个例的分析,提出相应的应对措施和排除方法,旨在积累经验达到快速排除故障的目的。     

南宁CINRAD／SA天气雷达无体扫产品故障浅析

描述南宁CINRAD/SA天气雷达出现无体扫产品故障的现象,介绍了故障定位和故障排除的过程,分析了导致此次故障的原因,讨论了CINRAD/SA天气雷达故障处理的一些方法.     

LOW-FREQUENCY CIRCULATION AND EXTENDED-RANGE FORECAST IN CONNECTION WITH AUTUMN EXTREME HEAVY RAINFALL PROCESS IN HAINAN

Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d.     

AN ATTRIBUTION ANALYSIS OF CHANGES IN POTENTIAL EVAPOTRANSPIRATION IN THE BEIJING–TIANJIN–HEBEI REGION UNDER CLIMATE CHANGE

Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region.     

ANALYSIS OF “BIMODAL PATTERN” STORM ACTIVITY CHARACTERISTICS OF THE BAY OF BENGAL

Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics.     

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正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.SUBMISSIONAll submitted     

A Brief Introduction to Marine Meteorological Science Experiment Base at Bohe Town,Maoming City,Guangdong Province

<正>With the support of specialized funds for national science institutions,the Guangzhou Institute of Tropical and Marine Meteorology,China Meteorological Administration set up in October 2008 an experiment base for marine meteorology and a number of observation systems for the coastal boundary layer,air-sea flux,marine environmental elements,and basic meteorological elements at Bohe town,Maoming city,Guangdong province,in the northern part of the South China Sea.     

Information for Authors

AIMS AND SCOPE
Atmospheric and Oceanic Science Letters （AOSL） publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.     

Information for Authors

AIMS AND SCOPE Atmospheric and Oceanic Science Letters （AOSL） pub- lishes short research letters on all disciplines of the atmos- phere sciences and physical oceanography. Contributions from all over the world are welcome.     

Information for Authors

正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences