SA型多普勒天气雷达故障维修综述

随着气象科技的不断发展,70年代生产的711雷达逐步退出了历史舞台,取而代之的是新一代天气雷达。目前,新一代天气雷达已在全国气象部门联网拼图并得以广泛的应用,在防灾减灾和社会经济建设中发挥着不可替代的作用。然而随着新一代天气雷达的普及应用,对它的日常维护和故障处理成了工作中的新课题。     

气象雷达探测系统在人工影响天气中的应用——以多普勒天气雷达为例

多普勒天气雷达是以多普勒效应为其基本的工作原理进行设计的,其在对降水的监测作用和降水量的定量估算等方面具有与其它气象雷达不同的优势。其不仅可以探测出关于降水方面的丰富的信息,同时还能较为清晰的识别出即将到来的降水的结构和类型,利用多普勒雷达研发出相关产品的有很多,比如说回波顶高度产品,就是利用回波来了解云层中对流的情况,还有就是垂直累积液态含水量产品,这个就是利用多普勒天气雷达对对流垂直面的含水量进行探测,分析由于对流带来的暴雨、冰雹等的可能性。本文就这两个产品进行了简单的介绍,并以人工增雨这个人工影响天气这个作业为例,介绍了利用多普勒雷达产品计算催化剂量的方法。     

CINRAD／CD多普勒天气雷达产品文件异常情况分析及处理

本文介绍了林芝新一代天气雷达产品缺少,体扫抬升异常,判断方位电机,伺服放大器故障,介绍伺服原理功能与组成,深入分析工作原理,对新一代天气雷达的维护保障工作具有重要意义。     

我国6年内发射10颗气象卫星 再建50多部天气雷达

中国气象局局长郑国光3月23日接受记者采访时说,在未来6年,我国将发射10颗气象卫星,再建50多部多普勒天气雷达,再建4万个左右的自动气象观测站。到2020年,气象监测的空间分辨率达到10公里左右,时间分辨率将达到分钟量级。监测密度的提高将大大提升气象预报预警的精细化水平和精准度,气象预报分辨率在城市将达到2—3公里,全国范围内达到5—10公里。     

714CD型天气雷达回波关联故障浅析

回波作为714CD型天气雷达性能的最直观表现之一,往往能够成为故障判断的切入口,本文从雷达的运行原理、信号流程着手,通过对雷达各分系统的功能剖析,结合赤峰市新一代天气雷达历史故障实例,浅析雷达分系统与回波故障的关系。     

卫星气象与空间天气监测预警标准化工作进展及发展对策

一、引言 经过30多年的发展,我国的气象卫星与卫星气象事业取得突破性进展,气象卫星已初步完成了由试验业务型向应用服务型的转变,从气象卫星获取的信息已广泛应用于天气预报、气候预测、生态环境和自然灾害监测等领域,在我国的国民经济发展和国防建设中发挥了重要作用。与此同时,随着我国航天事业和现代化建设的飞速发展,空间天气监测预警业务也迅速开展并受到越来越多的重视。     

《新一代天气雷达选址规定》等气象行业标准发布

中国气象局印发关于发布《新一代天气雷达选址规定》等11项气象行业标准的通告,批准这11项气象行业标准,并于2009年11月1日正式实施。这11项气象行业标准包括《新一代天气雷达选址规定》、《水稻、玉米冷害等级》、《气象资料分类与编码》、《雷电灾害调查技术规范》、《接地降阻剂》。     

基于鲁棒H∞滤波器的雷达测速方法

针对多普勒雷达测速模型具有不确定性和未知外部干扰的情况，建立了机载多普勒雷达测量飞机相对地球速度的状态方程，采用鲁棒H∞滤波器的线性矩阵不等式（LMI）综合方法，设计了鲁棒H∞滤波器。此滤波器不需要知道外部干扰和噪声的统计特性，并且使多普勒雷达速度测量的稳定性和适用性得到改善。计算机仿真表明了此方法的有效性。     

CINRAD／CD天气雷达网络问题引起体扫故障分析及处理

我国新一代天气雷达对气象目标的探测主要采用体扫模式。当天气雷达在体扫过程中,无法完成或间醉陛完成数据采集时,将严重影响雷达系统的可用性和业务运行质量。造成体扫故障的原因是多种多样的,本文结合实际工作,重点对网络原因导致的体扫故障进行分析,总结相应的故障排除方法和维护要点,以供大家参考。     

基于雷达多普勒频移原理的机动车超速自动监测系统的计量检定

对基于雷达多普勒频移原理的机动车超速自动监测系统的检定．包括雷达测速单元的检定和现场测速误差的检定。现场测速误差的检定在JJG527—2007《机动车超速自动监测系统》检定规程中有明确的方法,这里重点讨论雷达测速单元的计量和检定。     

Bird migration flight altitudes studied by a network of operational weather radars

A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which—when extended to multiple radars—enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe.     

气象探测雷达模拟训练系统的研制

介绍了气象探测雷达模拟训练系统的组成、工作原理、主要技术及该模拟训练系统的硬件电路设计与软件设计．该系统是专为某种气象探测雷达模拟训练设计，达到了不使用雷达、不放探空气球即可对操作手进行全仿真训练的目的，具有很高的实用性和可操作性．     

Developments in radar and remote-sensing methods for measuring and forecasting rainfall

Over the last 25 years or so, weather-radar networks have become an integral part of operational meteorological observing systems. While measurements of rainfall made using radar systems have been used qualitatively by weather forecasters, and by some operational hydrologists, acceptance has been limited as a consequence of uncertainties in the quality of the data. Nevertheless, new algorithms for improving the accuracy of radar measurements of rainfall have been developed, including the potential to calibrate radars using the measurements of attenuation on microwave telecommunications links. Likewise, ways of assimilating these data into both meteorological and hydrological models are being developed. In this paper we review the current accuracy of radar estimates of rainfall, pointing out those approaches to the improvement of accuracy which are likely to be most successful operationally. Comment is made on the usefulness of satellite data for estimating rainfall in a flood-forecasting context. Finally, problems in coping with the error characteristics of all these data using both simple schemes and more complex four-dimensional variational analysis are being addressed, and are discussed briefly in this paper.     

基于风廓线雷达技术的沙尘天气监测研究

利用塔克拉玛干沙漠大气环境观测试验站2010年4月11日沙尘天气风廓线雷达资料,分析了此次过程启动爆发的水平风场、垂直速度和雷达等效回波强度特征。研究表明:风廓线雷达是进行沙尘探测和监测的一种有效的高空大气遥感系统,它不仅可以捕捉到沙尘天气的开始和结束时间,而且能监测到沙尘在空中被输送的高度、厚度范围以及沙尘运动的垂直强度特征;塔克拉玛干沙漠扬沙和沙尘暴雷达等效回波强度约为-3～10 dBZ,浮尘等效回波强度约为-15～-3 dBZ;水平风垂直切变以及低空东风的维持是此次沙尘天气发生的动力成因。扬沙、沙尘暴发生时,大气垂直速度表现为上升运动,在较大水平风速及干燥下垫面的配合下,导致地面沙粒被输送到高空,形成了沙尘天气。     

Mine surface subsidence monitoring due to impacts of underground mining using persistent scatterer interferometry

The Singhbhum shear zone in India is well known for its historical underground copper mining activity. As a consequence, today some abandoned underground mines pose a serious risk to the local people and property. Thus it is essential for a long-term wide-range monitoring technique to map the surface subsidence over the mining areas. In this study, it has been tried to establish occurrence of ground subsidence with an advanced differential interferometric synthetic aperture radar technology called persistent scatterer interferometry, which is known for its capability of high-precision monitoring. The results clearly indicate trends of surface subsidence over abandoned mining regions.     

高心墙堆石坝填筑施工过程实时监控系统研发与应用

文章针对高心墙堆石坝填筑施工特点,建立了过程控制指标体系,确定了过程监控方法,提出了解决方案,研制开发了具有实时性、高精度、自动化、全天候等特点的大坝填筑施工过程监控系统,实现土石料上坝运输过程、坝面填筑碾压过程的实时监控。该系统应用于亚洲第一高土石坝———糯扎渡心墙堆石坝的施工现场,建立了以监控系统为核心的施工过程控制体系,对大坝填筑施工的主要环节实现精细化的全天候实时监控,有效地控制了大坝填筑施工参数,提高了施工过程的质量控制水平与效率。     

大气科学的工程化建设

文章概述了大气科学的涵义及其对人类生存和发展的重要性,包括防灾减灾、气候资源的开发利用、生态环境的保护、水资源的可持续利用等。大气科学造福人类的途径是通过大气信息的开发利用,而必须按信息工程的特点进行工程化。简要回顾气象主要工程建设的基本情况及其应用效益,提出未来30年内的发展和大气科学工程建设的基本思路、需要建设的若干骨干工程：大气监测自动化系统工程、短期气候预测业务系统工程、卫星综合应用业务系统延伸工程、中尺度（局地）数值天气预报业务系统工程、人工影响天气系统工程、气象服务体系工程等,以及进行建设的若     

Applicability of Doppler weather radar based rainfall data for runoff estimation in Indian watersheds – A case study of Chennai basin

Traditionally, India has been vulnerable to various hazards such as floods, droughts and cyclones. About 8% of the total Indian landmass is prone to cyclones. A number of Doppler weather radars are installed in India and their products are utilized for weather predictions and detection of cyclones approaching the Indian coast. Radar-based hydrological studies in various countries have proven that computation of runoff using radar rainfall data could outperform rain gauge network measurements. There are no reported studies on their utilization for hydrological modelling and/or flood-related studies in Indian river basins. A comparison study between Doppler weather radar (DWR) derived rainfall data and the conventional rain gauge data was carried out with hourly inputs at one of the watersheds of Chennai basin, Tamil Nadu, India using HEC-HMS model. The model calibration and validation were performed by comparing the simulated outflow with the observed daily outflow data. The calibrated model was used to predict runoff from two post-monsoon cyclonic storm events with hourly inputs. It was noticed that the discrepancy in the runoff volume was small, but the difference in the peak flow was substantial. Additionally, there was a variation at the time to peak flow using daily and hourly inputs. The results show that the use of radar data may be optional for runoff volume estimation for the watersheds with sufficient rain gauge density, but highly desirable for peak flow and time to peak estimation. Therefore, the DWR derived rainfall data is a promising input for runoff estimation, especially in urban flood modelling.     

Radar-echo tracking by use of invariant moments

A number of techniques to track rainfall patterns by use of radar observations have been developed over the years. We present a method for radar-echo tracking based on Hu invariant moments. The method has been tried on several sequences of test images, and the derived displacement fields were in good agreement with the real motions of the tested objects. For the real data obtained from the conventional meteorological radar in Legionowo the method occasionally failed when changes in the radar echo between observations were too large.     

Experimental investigation of directional characteristics for ionospheric clutter in HF surface wave radar

The unwanted radar echoes from the ionosphere are collectively called ionospheric clutter. It has proved to be the greatest impediment to achieve consistently good performance in long-range detection of surface vessels and sea-state monitoring for high-frequency surface wave radar (HFSWR). Field experimental data recorded by the HFSWR OSMAR2003 (Ocean State Monitor and Analysis Radar, manufactured in 2003) has been used in detailed investigations of the directional characteristics for this ionosphere clutter, leading to the development of effective mitigation techniques based on antenna design and adaptive signal processing. Particular attention is given to the amplitude and phase relationship among multiple spatial channels for two types of ionospheric clutter. Preliminary experimental results show that the random gain and phase variation of the antenna pattern overhead null destroyed the amplitude and phase consistency among channels. As a result, no significant measured directivity is observed in this type of specular clutter. For the incidence clutter from a lower elevation angle, it is observed that the spread clutter possesses high directivity. A nonlinear receiving array composed of multiple V-shaped antennas without deep and broad null at near-vertical incidence is proposed for adaptive ionospheric clutter suppression