90年代天气雷达监测网建设与发展

介绍美国、欧洲、中国９０年代高级天气雷达监测网建设与发展概况和瑞士的Ｍｅｔ－Ｎｅｔ高级气象雷达数据网系统的主要技术特色     

气象雷达地物杂波抑制器

气象雷达是中小尺度天气预报的主要大气探测工具之一。地物杂波严重干扰气象回波信号的识别、影响降雨量的定量测定和雷达数据的进一步处理,本课题从经济和现役天气雷达的现状出发选用非相参三脉冲对消器来抑制地物杂波,提取气象信号。本抑制器在脉冲重复频率200Hz,天线转速3转/分,脉冲宽度2μs,波长6.6cm的713雷达上作实验,取得地物杂波抑制比大于21分贝,气象信号损失小于5分贝的结果。 本文对气象雷达地物杂波抑制器的可取方案进行简要分析,给出二脉冲和三脉冲对消器的杂波和气象信号的衰减曲线,对本课题的非相参MTI系统进行说明,最后给出外试验埸结果、分析以及今后的工作的设想。     

基于小波变换改善天气回波信噪比的模拟分析

为了提升天气雷达对弱气象目标的发现能力,扩展系统观测的动态范围,可以从改善雷达回波的输出信噪比方面来考虑.从信号处理算法层面寻求改善天气雷达回波的输出信噪比的方法,提出运用小波变换的方法来达到这个目的.首先介绍了小波消噪的基本原理,再结合具体雷达系统参数,进行了相关的算法模拟,其结果表明,在符合高斯谱特征分布的模拟回波在不同信噪比（-20～10dB）设定条件下,运用小波变换的去噪方法可以使其信号的输出信噪比提高大约5～11dB,为天气雷达探测更多的弱气象目标提供了有利条件.     

多普勒天气雷达二维理想均匀风场的数值模拟

对风场结构和信息的探测始终是气象科学的重要研究方向。多普勒天气雷达是研究大气边界层风场的有力手段,有效地利用其径向速度资料分析和推断真实的风场结构,能够大大提高中小尺度天气系统预报的准确度。基于单多普勒天气雷达探测风场反演技术,用Matlab实现二维理想均匀风场的多普勒天气雷达径向速度图模拟。考虑到雷达系统的工作波长和脉冲重复频率的差异可能导致观测结果产生速度模糊的问题,以风向风速各自随高度变化与否以及如何变化的4种风场情况,分别给出了S、C、X波段的多普勒天气雷达径向速度模拟图,并且设计了相应的GUI界面。通过分析模拟的径向速度平面位置显示图,帮助反演真实的风场信息。     

一种CINRAD雷达基数据读取丢失的改进方法

多普勒天气雷达是目前世界上最先进的气象雷达,已成为对灾害性天气监测、预警的重要手段之一.雷达基数据的读取是做雷达应用软件的基础,针对目前常规方法对雷达基数据的读取遇到的数据丢失的问题,提出一种改进方法.通过对大量数据的分析和读取,发现新的方法能够有效地提取出丢失数据,并且能够根据丢失数据的重要性对图像进行修正,对小尺度龙卷天气的分析有重要意义.     

WRDPS天气雷达数据处理系统与气象教育

本文对现代天气雷达终端WRDPS的工作,性能指标和应用进行了评述,分析了关键技术,阐述了WRDPS与气象教育的关系。     

新一代天气雷达资料图像产品的生成方法

介绍了新一代天气雷达产品显示、以通用格式(BMP为例)自动保存图像文件、图像说明信息中文化的技术方法.重点对雷达产品显示资料处理中扇区填充的两种方法(屏幕坐标反查法和线段填充法)及其技术差别进行了比较分析.结果表明,屏幕坐标反查法较线段填充法原理简单,但计算复杂,对数据资料要求严格,在实际应用中易出现较大误差.     

新一代天气雷达数字化处理终端

成都气象学院大气电子工程系研制的新一代天气雷达数字化处理终端,具有体积小,结构紧凑,功能齐全,开发潜力大的特点。系统硬件全部插入微机的扩展槽内,同雷达联机实时采集处理。系统采用了先进的超大规模集成电路(TMS320C25单片高速数字信息处理器),从而大大简化硬件逻辑电路,使系统的稳定性和可靠性大大提高,数据处理的能力大大增强,速度大     

天气雷达数据处理系统的设计与实现

天气雷达数据处理系统是“全国天气雷达终端更新”项目的关键,其目的就是要实现雷达回波信号的高速采集与处理、天线控制、实时显示与存储、回波强度定标等功能。设计中,利用复杂可编程逻辑器件（CPLD）和QuarmsII设计软件,产生各种复杂的时序逻辑控制时钟,协调信号处理器、天线控制器中各功能电路的工作。实现的数据处理系统达到了系统的技术指标,通过实际使用证明,系统性能稳定可靠、结构简单、界面友好、操作方便、便于升级,完全能够实时、高效地处理常规天气雷达信号。     

天气雷达数据处理系统的设计与实现

天气雷达数据处理系统是“全国天气雷达终端更新”项目的关键,其目的就是要实现雷达回波信号的高速采集与处理、天线控制、实时显示与存储、回波强度定标等功能。设计中,利用复杂可编程逻辑器件（CPLD）和quartusⅡ设计软件,产生各种复杂的时序逻辑控制时钟,协调信号处理器、天线控制器中各功能电路的工作。实现的数据处理系统达到了系统的技术指标,通过实际使用证明,系统性能稳定可靠、结构简单、界面友好、操作方便、便于升级,完全能够实时、高效地处理常规天气雷达信号。     

重庆雾害潜势预报、警报系统中的显示服务系统

本文介绍重庆市区雾害潜势预报报警服务系统的显示服务系统。该系统包括资料处理、动力、统计、数值预报、客观推理系统、综合决策(集成)等模式,以及系统简介和显示服务等功能。显示服务系统采用菜单技术,多种语言混合编程,能正确运行各个模式,完成所需功能,具有实用、方便、直观和自动化程度高的特点,在实用中收到良好效果。     

光栅扫描在渔航仪器中的应用问题

根据生产实践的反映,从工作原理出发,讨论光栅扫描显示技术在助渔、导航仪器中应用的优缺点。     

老化产品计时器制作的几种设计、研制方案

利用Ｚ－８０实时时钟制作老化产品的计时器，具体通过Ｚ－８０ＴＰ８０１单板机控制来实现，使老化产品时间更加准确。除了计时、分、秒外，还可以计天（日），计时的时间可在显示器上直接观察，使人们了解老化产品时间是否已到，从而增加老化产品时间的精确性。     

Preliminary study on plasma membrane fluidity of Psychrophilic Yeast Rhodotorula sp.NJ298 in low temperature

The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprehensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose     

JOURNAL OF OCEAN UNIVERSITY OF CHINA

<正>Copyright Submfnion of a roanusatpt inks:that the work described has not been published before(exoept In the form of an abstrW or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere that its publication has been approved by ail     

Information for Authors

<正>The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research results on oceanography and marine fisheries.The fieldcovered include the physical,chemical,biological,geo-     

Hydraulics and Hydrology in Mountain Areas

<正>The 35th IAHR World Congress was held in Chengdu,China from September 8 to September 132013.The title of the conference was:"The Wise Finds Pleasure in Water:Meandering through Water Science and Engineering".During the congress,1239 papers were presented in 139sessions for oral presentations and 7 sessions for poster presentations.After the Congress,a Committee was appointed to select some of the best papers presented at the Congress for publication,after a     

Sea ice thickness measurement in spring season in Bothnian Bay using an electromagnetic induction instrument

As an important component of the cryosphere,sea ice is very sensitive to the climate change.The study of the sea ice physics needs accurate sea ice thickness.This paper presents an electromagnetic-induction(EM) technique which can be used to measure the sea ice thickness distribution efficiently,and the successful application in Bothnian Bay.Based on the electromagnetic field theory and the electrical properties of sea ice and seawater,EM technique can detect the distance between the instrument and the ice/water interface accurately,than the sea ice thickness is obtained.Contrastive analysis of the apparent conductivity data obtained by EM and the value of drill-hole at same positions allows a construction of a transformable formula of the apparent conductivity to sea ice thickness.The verification of the sea ice thickness calculated by this formula indicates that EM technique is able to get reliable sea ice thickness with average relative error of only 12%.The statistic of all ice thickness profiles shows that the level ice distribution in Bothnian Bay was 0.4-0.6 m.