城市地下管线的测绘及数据管理     

朱春晓 《测绘与空间地理信息》2003,26(1):15-17

介绍城市地下管网从野外采集数据到内业成图一体化作业过程,并同步建立管网信息库、地理信息库,实现GIS平台上对管网的科学管理。  相似文献   

数码相机可量测化的研制   总被引：22，自引：0，他引：22  

杨朝辉  李浩  杨林 《测绘工程》2003,12(2):34-37

普通数码相机在图像获取方面有着很多优势，但它是非量测化相机，不能用普通数字摄影测量方法对其数字图像进行处理。针对这一情况，本文进行了数码相机的可量测化研制，并将其投入实际应用。实际应用的结果证明研制工作是成功的。  相似文献   

基于数码相机的孔群定位与数控钻孔   总被引：7，自引：0，他引：7  

冯文灏  李建松  阎利  苏国忠  袁修孝  钟生长  冀慧明 《测绘学报》2003,32(3):229-233

提出基于数码相机摄像、螺孔影像中心定位、多站摄像、自检校光束法平差、螺孔群的一次定位以及数控钻孔的一整套新生产流程。强调在摄像测量中以像素为单位表示像方所有量(包括像点坐标、内方位元素和各类畸变)的可行性，而且此种措施简化了非方形像素间隔的检校。  相似文献   

上海城市三维景观模型的制作   总被引：6，自引：0，他引：6  

万从容  赵峰  程远达  楼恺达 《测绘信息与工程》2003,28(6):19-20

通过实践分析了城市三维建模技术的现状，并提出了在数字城市建设中城市三维建模的要点以及今后的研究方向。  相似文献   

数字工程建设与空间信息产业化   总被引：5，自引：1，他引：5  

宁津生  张目 《武汉大学学报(信息科学版)》2003,28(1):1-3

从当前数字工程建设的现状与需求出发，论述了数字工程的概念和技术特点，指出数字工程的技术创新和应用拓展将会进一步推动空间信息产业化。  相似文献   

HUBEX强化观测期雷达测雨在水文过程模拟中的应用     

任立良  李春红  王美荣 《大气科学进展》2003,20(2):205-212

选择全球能量与水循环亚洲季风试验区的淮河黄泥庄水站控制的史河流域(805km^2)为研究区域，基于数字高程模型，生成栅格水流流向，构建数字流域及空间拓扑关系；然后，将阜阳雷达观测数据经过订正校准后作为研究区内每一栅格单元上的雨量输入，并在每一栅格上应用新安江模型构建产流模型；再根据每一栅格至流域出口断面一黄泥庄水站的距离，运用Muskingum方法进行汇流演算，从而获得黄泥庄站的流量过程。计算结果显示，从1998年5月31日。8月3日的强化观测期内模型确定性系数为92．41％，其间4场洪水的确定性系数分别为85．64％、86．62％、92．57％和83．91％，高于应用地面雨量计观测的数据计算的结果。这说明雷达测雨数据具有较高的时空分辨率，当它应用于水过程模拟时优于地面雨量计资料，基于栅格的水模型为充分利用雷达数据提供了良好平台。  相似文献   

Digital photogrammetry as a tool in analogue modelling: applications to volcano instability     

F. Donnadieu  K. Kelfoun  B. van Wyk de Vries  E. Cecchi  O. Merle 《Journal of Volcanology and Geothermal Research》2003,123(1-2):161

Three techniques of digital photogrammetry have been applied successfully to laboratory analogue models to study surface displacements caused by various volcano deformation types. Firstly, side-perspective videos are used to differentiate profile displacements between cryptodome intrusion models and models deforming by ductile inner-core viscous flow. Both models show similar morphologic features including a bulged flank and an asymmetric upper graben. However, differences in displacement trajectories of the bulge crest reflect upward intrusion push contrasting with essentially downward displacement vectors of weak core models. The other two techniques use vertical views correlated automatically either as time-sequence monoscopic views or as coeval stereoscopic pairs. This exploits to a maximum the method’s potential by imaging surface displacements over the whole model. Successive monoscopic photograms, because they suffer only moderate numerical processing for topographic effect removal, can detect very small displacements occurring early in deformation processes. As illustrated by analysis of intrusion models, the monoscopic method allows prediction of fault locations and main displacement locations. It can also anticipate the principal strain directions, and separate different deformation stages. On the other hand, the stereo-photogrammetry technique, although more complicated, provides topography and volume changes, as well as pictures of surface displacements in three dimensions. Results are presented for the spreading of volcano models on a ductile substratum and viscous cored cones. We have found digital photogrammetry to be a useful tool for analogue modelling, because it provides quantitative data on surface displacements, including movement invisible to the eye, as well as topographic changes. It is a good method for investigating and comparing different deformation mechanisms. It is especially useful for interpretation of displacement patterns obtained from monitoring of natural active volcanoes. In fact, results of the methods used in the laboratory can be directly compared with field data from geodetic or photogrammetric surveys, as at Mount St. Helens in 1980.  相似文献   

Effect of causal and acausal filters on elastic and inelastic response spectra     

David M. Boore  Sinan Akkar 《地震工程与结构动力学》2003,32(11):1729-1748

With increasing interest in displacement spectra and long‐period motions, it is important to check the sensitivity of both elastic and inelastic response spectra to the filtering that is often necessary to remove long period artifacts, even from many modern digital recordings. Using two records of very different character from the M=7.1, 1999 Hector Mine, California, earthquake, we find that the response spectra can be sensitive to the corner periods used in causal filtering, even for oscillator periods much less than the filter corner periods. The effect is most pronounced for inelastic response spectra, where the ratio of response spectra computed from accelerations filtered at 25 and 200 sec can be close to a factor of 2 for oscillator periods less than 5 sec. Published in 2003 by John Wiley Sons, Ltd.  相似文献   

大型数字减影血管机手术床移动故障分析与维修     

张世龙 《CT理论与应用研究》2003,12(2):30-32

手术床是大型影像设备DSA(digital subtraction angiography)的重要部件，它的故障比其它部件多。本文讨论了手术床的移动故障，也分析了在CPU控制下机械部件的维修方法。  相似文献   

2000年姚安地震的震源参数   总被引：16，自引：0，他引：16       下载免费PDF全文

秦嘉政  叶建庆  钱晓东  李白基  王绍晋 《地球物理学报》2003,46(5):633-641

根据近场小孔径观测台网记录的余震序列资料，研究了2000年1月15日云南姚安MS6.4地震序列的地震物理过程. 用地震标定律关系估算主震的地震矩M0=1.58×1018N·m，矩震级MW=6.0，平均位错=0.63m，断层长度L=16.6km，断层宽度W=5.6km. 余震序列的高精度定位结果和能量分布走向，很好地证实了主震的断层破裂走向为N50°W，震区马尾菁断裂为主震发震构造，断层错动性质以右旋走滑为主. 用横波记录资料及波谱分析方法估算出余震的震源参数: 地震矩范围为1010～1016N·m，震源破裂半径a为80～500m，地震应力降范围为0.01～9.5MPa. 较大应力降(Δσ>1.0MPa)沿主断层线性排列，大应力降(Δσ>2.0MPa)与ML≥3.0级地震相关. 余震能量释放和高应力降的地震多发生在6.0～11km的深度范围，说明在这一深度范围内最大程度地集中了地壳中的应力.  相似文献