共查询到20条相似文献，搜索用时 203 毫秒
1.
Dynamic characteristics of large structures,such as tall buildings,long-span suspension,cable-stayed bridges and tall chimneys,are key to assess their drift and stress conditions.The dynamic characteristics of large structures are difficult to measure directly under the condition of earthquakes or strong winds using traditional techniques such as laser collimator,total station and accelerometers.Therefore there is a great need for developing new method or technique for this purpose.Recent advances in Global Positioning System (GPS) technology provide a great opportunity to monitor long-period changes of structures reliably.GPS receivers capable to gauge the motion at the centimeter or sub-centimeter level with sampling frequency 10Hz or even 20 Hz are now available from several manufacturers.To the authors' knowledge,the capability of identifying dynamic characteristics from GPS observations has not been widely verified.For the feasibility study on using kinematic GPS technology to identify the dynamic characteristics of tall buildings,some experiments were conducted in a simulative environment.This paper discusses in detail the experiment device,and the ways through them GPS data are recorded,processed and analyzed.With post-processing version of NovAtel's Softsurv software and auto-regressive (AR) spectral analysis method,relative displacements and corresponding vibrating frequencies have been derived from GPS observations.The results indicate that the dynamic characteristics can be identified accurately by kinematic GPS technology. 相似文献
2.
GeoStar is the registered trademark of GIS software made by WTUSM in China.By means of the GeoStar,multi-scale images,DEMs,graphics and attributes integrated in very large seamless databases can be created,and the multi-dimensional dynamic visualization and information extraction are also available.This paper describes the fundamental characteristics of such huge integrated databases,for instance,the data models,database structures and the spatial index strategies.At last,the typical applications of GeoStar for a few pilot projects like the Shanghai CyberCity and the Guangdong provincial spatial data infrastructure (SDI) are illustrated and several concluding remarks are stressed. 相似文献
3.
CHENG Penggen GONG Jianya WANG Yandong SUI Haigang CHENG Penggen Doctoral Candidate Associate Professor National Laboratory for Information Engineering in Surveying Mapping Remote Sensing WTUSM Luoyu Road Wuhan China 《地球空间信息科学学报》1999,2(1):78-85
The key to develop 3-D GISs is the study on 3-D data model and data structure. Some of the data models and data structures have been presented by scholars. Because of the complexity of 3-D spatial phenomenon, there are no perfect data structures that can describe all spatial entities. Every data structure has its own advantages and disadvantages. It is difficult to design a single data structure to meet different needs. The important subject in the3-D data models is developing a data model that has integrated vector and raster data structures. A special 3-D spatial data model based on distributing features of spatial entities should be designed. We took the geological exploration engineering as the research background and designed an integrated data model whose data structures integrats vector and raster data byadopting object-oriented technique. Research achievements are presented in this paper. 相似文献
4.
CHEN Yongqi TANG HongwaiCHEN Yongqi Professor School of Geo-science Surveying Engineering WTUSM Wuhan China 《地球空间信息科学学报》1998,(1)
A monitoring scheme must be so designed that several possible mod-els can be efficiently separated in the stage of analysis of deformation measure-ments.Based on the concept of separability developed by Chen and Chrzanowski,a methodology for the design of monitoring schemes has been developed by the au-thors.In the method a computer simulation technique is employed,into whichsome rules have been elaborated allowing minimal human intervention.In this pa-per the criterion is first presented and the design technique using the step one up-dating procedure is discussed.Finally,design of a simulated monitoring networkis made as a demonstrating example. 相似文献
5.
CHENGPenggen SHIWenzhong GONGJianya ZHOUGuoqing 《地球空间信息科学学报》2005,8(1):64-71
3D spatial data model and simulating are the core of 3D GIS can be adopted in different domains. A data model based on Quasi Tri-Prism Volume (QTPV) has been proposed. QTPV definition and its special cases have been discussed. Using QTPV and its special cases, irregular natural geological bodies and regular subsurface engineering can be described efficiently. The proposed model is composed of five primitives and six objects. Data structures and topological relationship of the fives primitives and three objects describing stratigraphy are designed in detail Some schemes are designed for the QTPV modelling of stratigraphy and subsurface engineering according to modelling data. The model manipulation method of QTPV cutting by an arbitrary plane is discussed. Using VC 6.0 programming language integrated with SQL database and OpenGL graphic library under windows environment, a system prototype 3DGeoMV has been developed. The experiment result shows that the QTPV model is feasible and efficient in modelling subsurface engineering. 相似文献
6.
DU Qingyun WU HehaiDU Qingyu Associate Professor School of Land Science WTUSM Wuhan China 《地球空间信息科学学报》1998,(1)
The main purpose to develop a Map Graphic Workstation on thewidely used micro-computer is that by it the whole processing of map data fromcapturing,managing,editing,updating to graphic outputting can be realized.Map Digitization System（MDS）is the software system to deal with the initial andalso the most important processing.In this paper,the authors introduce a MDSon a micro-computer based Map Grphic Workstation that has been qualitified forthe producation of digital map.Since the system is designed totally independentlyand in the general frame of the Map Graphic Workstation,the capturing and man-aging and other processings for map data are in an integral manner,in which theproducation of digital map can be fulfilled conveniently.At the same time,thesystem is flexible for function extension and widely applicable to the data from dif-ferent sources and with different information characterisitcs(e.g.,the processingof Chinese characters on map). 相似文献
7.
《地图》1989,(2)
In this paper,authors introduce the establishment of a Micro-computer Based Geographic Information System(MCGIS),which is one of the subsystems of The Loess Plateau Geographic Information System (LP-GIS) being carried out by the REIS Laboratory and several universities of China on various types and levels of computer.MCGIS is developed on the micro-computer Gteat Wall-286.Its purpose is to providean information system with powerful perforrmance,which could be afforded by thosecounty-level units or departments,so that the general guide-line of multi-function,multi-level and multi-user can come to practice. The system MCGIS is composed of the spatial database management systems and some software packages for geographic analysis and other further data processing.The spatial database management svstem is the kernel part of the MCGIS,and other function packages are babed on it.The whole system remains open, i.e.,ready to be extende in function. 相似文献
8.
YU Bo LIU Yanchun ZHAI Guojun BIAN Gang XIAO Fumin 《地球空间信息科学学报》2007,10(3):186-190
The detection and identification of the seabed cable is becoming an important task in the marine engineering. The features of the magnetic anomaly can be used to detect the existence of the seabed cable. The magnetic field model is presented, and the consistency of the magnetic anomaly distribution between the simulation of the model and the observed data is verified. The comparison shows that the seabed cable can be effectively detected and identified with reasonable method. 相似文献
9.
Spatial object and spatial relationship are two basic concepts of GIS.Spatial object is the digital representation of geographical entity or phenomenon,which forms the basis for data management and analysis;spatial relationship is theconnexion between spatial objects when geometric properties are considered.Thecommonly used classification of spatial objects as points,lines and areas is mathe-matically strict,and suitable for data management,but a bit too generalized forrepresenting real entities and extracting spatial relationships.A good classificationmodel should not only be good for representing real entities,but also good for re-vealing spatial relationships,therefore good for formalizing spatial analyses. 相似文献
10.
《地图》1989,(2)
The design of map color is an important part in map design, especially for thematic mapping, importance is no less than that of map content itself.Tranditional method in map color design is to make several designing variants and then make a comparison among them and finally choose one of them.This method is time-consuming and rather expensive.With the development of interactive computer graphics,now the design of map color can be completed by means of computer processing. During this procedure, cartographer's knowledge in map design, rich color in computer and the powerful functions of graphic processing of computer can be combined together. Three main problems about comprter-aided design of map color are discussed in this paper: The first is to create a database which forms the basis of color producing; the second is to create a cartographic database for organized raster data; the third is to design an interactive svstem for the design of map color with the support of the two databases mentioned above. 相似文献
11.
数字图像监测系统应用于高压导线覆冰试验(英文) 总被引：1，自引：0，他引：1
A real-time system of numeral image manipulation technology is employed to inspect the dynamic displacement of an engineering
structure. First, the CCD vidicon aims at the fixed point. The image of the fixed point on the structure is gathered by a
picture gathering card. By processing pictures with a self-programmed software, the real-time space coordinate of the calibration
device can be obtained. Finally, the data is dealt with to get the movement curve, and the dynamic displacement is carried
out. The system is applied to the test of a high voltage icing conductor. The result indicates that the dynamic data of the
ice shedding conductor includes jumping amplitude, displacement-time curve and attenuation process.
Supported by the National Natural Science Foundation of China (No.50778077, No.50608036). 相似文献
12.
主要研发基于Mobile GIS技术、GNSS CORS技术、网络通信技术、常规测量技术以及移动计算平台的开采沉陷实时数据采集终端,以到达对铁路移动变形信息实时采集和监控的目标。研发基于数据库技术和软件工程技术的面向对象的数据处理和分析系统,在数据处理中心进行铁路移动变形信息的精化处理分析;根据预计的地表移动变形信息,建立井下开采对铁路及其主要附属建(构)筑物动态影响的三维虚拟现实模型并进行预警。研究成果为列车安全运行及煤矿安全生产提供决策依据。 相似文献
13.
Global Positioning System (GPS) is being actively applied to measure static and dynamic displacement responses of large civil engineering structures under winds. However, multipath effects and low sampling frequencies affect the accuracy of GPS for displacement measurement. On the other hand, accelerometers cannot reliably measure static and low-frequency structural responses, but can accurately measure high-frequency structural responses. Therefore, this paper explores the possibility of integrating GPS-measured signals with accelerometer-measured signals to enhance the measurement accuracy of total (static plus dynamic) displacement response of a structure. Integrated data processing techniques using both empirical mode decomposition (EMD) and an adaptive filter are presented. A series of motion simulation table tests are then performed at a site using three GPS receivers, one accelerometer, and one motion simulation table that can simulate various types of motion defined by input wave time histories around a pre-defined static position. The proposed data processing techniques are applied to the recorded GPS and accelerometer data to find both static and dynamic displacements. These results are compared with the actual displacement motions generated by the motion simulation table. The comparative results demonstrate that the proposed technique can significantly enhance the measurement accuracy of the total displacement of a structure. 相似文献
14.
海洋平台及其桩腿在长期使用中存在着波浪、海流、风荷载等环境激励作用下的动态响应。本文以海星达H32全能型GNSS RTK双频接收机为试验仪器,采用GPS+GLONASS+BDS三星系组合系统对位于渤海海域的埕岛油田某平台桩腿进行动态变形监测。结合Ensemble Empirical Mode Decomposition(EEMD)和Butterworth滤波方法的降噪特性,提出一种适用于海洋平台工作环境的新型混合滤波方法 MDB,并用Matlab软件编制的程序对GNSS RTK监测数据进行分析,得到桩腿测点的实时振动位移曲线。结果表明:GNSS RTK结合MDB滤波技术用于海洋平台桩腿动态变形监测是可行的;MDB滤波器能有效去除海洋平台振动信息的随机噪声和多路径误差;从去除多路径误差和随机噪声之后的海洋平台桩腿测点位移云图,可以非常清楚地看出桩腿在环境激励作用下水平方向产生的可逆位移轨迹,这对海洋平台结构健康监测、诊断和评估具有重要意义。 相似文献
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柴永杰 《测绘与空间地理信息》2011,34(4):119-121
基于笔者多年从事变形及动态检测的相关工作经验,以GPS技术在大型建筑物动态监测中的应用为研究对象,分析探讨了GPS动态监测的原理和方法,借助实例评价了GPS在大型结构动态监测中的应用状况,最后,笔者简要阐述了监测数据的管理与可视化方法,全文是笔者长期工作实践基础上的理论升华,相信对从事相关工作的同行有着重要的参考价值和... 相似文献
18.
GNSS和加速度计是目前动态监测超高建筑环境载荷变形的主要手段。GNSS具有无需通视、可直接获取三维位移等优点,但受精度和采样率的限制,其对微变形及高频振动信息不敏感;而加速度计具有高精度和高采样率等优点,但无法监测超高建筑低频的似静态变形。为充分发挥这两种传感器的各自优势,提出利用多速率Kalman滤波和RTS平滑方法对超高建筑GNSS和加速度计监测数据进行融合处理。试验结果表明,与单一的GNSS监测技术相比,该方法有利于削弱GNSS高频噪声的影响,提高位移数据的采样率,可有效识别超高建筑的低频和高频振动频率,提高对微变形振动的监测能力;与单一的加速度计监测技术相比,该方法可以准确监测超高建筑的低频变形信息,具有良好的工程应用价值。 相似文献
19.
针对自由设站方案,建立了通过观测监测点与基准点的水平距离,利用距离收敛值监测基坑边坡水平位移量的方法,特别给出了采用全站仪对边测量深层水平位移的方法。借助等影响原则和基准点已有信息,分析了基坑位移监测方法和距离收敛测量原理及精度,实现了位移监测点的差分计算与数据处理,讨论了两种距离收敛法监测水平位移的精度,并将其用于实际观测。分析结果与工程实测数据均表明该监测方法观测精度满足规范要求,且量测效率高,具有良好的应用价值。 相似文献
20.
随着建筑行业的飞速发展,全国各地新建了大批复杂钢结构,其结构复杂,建筑体量巨大,在钢结构建筑施工的过程中,为了进行精确的钢结构拼接和方便其他部件的安装,需要获取钢结构部件上的特征信息。传统钢结构建筑物的安装与检测获取特征信息困难,延误施工工期。三维激光扫描可以通过大范围密集扫描快速获取钢结构的点云数据,经过处理可以获取钢结构的特征信息。本文以周口店北京人遗址大型钢结构圆盘构件节点坐标获取为例,介绍了钢结构点云数据的获取和数据处理流程,提出了基于几何位置关系的构件节点坐标提取方法。结果表明,采用三维激光扫描技术可以快速准确地获取工程坐标系下的钢结构构件特征,从而满足工程精度的要求。 相似文献