基于广义点摄影测量的后方交会与前方交会方法研究   总被引：1，自引：0，他引：1  

孔胃  张学明  何建美 《测绘科学》2011,36(5):45-48

广义点摄影测量将传统的点摄影测量和当代发展的线摄影测量以及无穷远点理论综合升华,将摄影测量中处理的物理意义上的点扩展到数学意义上的广义点.本文主要研究广义点摄影测量理论下的后方交会和前方交会解算方法.分析评价了不同控制线分布情况对后方交会精度的影响;依据前方交会原理,对闭合直线段和圆进行了三维重建,取得了良好的效果.  相似文献   

电力线实时测距方法研究     

郑顺义  胡华亮  黄荣永  季铮 《武汉大学学报(信息科学版)》2011,(6):704-707

从摄影测量原理出发,结合电力线测距的特点,分析了电力线的摄影几何,提出了相应的电力线位置确定策略及满足电力线实时测距要求的基于物方匹配的计算方法,并对实时测量的技术难点进行了分析。模拟实验和实际实验验证了此方法的可行性。  相似文献   

Evaluation of the controls affecting the quality of spatial data derived from historical aerial photographs     

Jan Walstra  Jim H. Chandler  Neil Dixon  Rene Wackrow 《地球表面变化过程与地形》2011,36(7):853-863

This paper is concerned with the fundamental controls affecting the quality of data derived from historical aerial photographs typically used in geomorphological studies. A short review is provided of error sources introduced into the photogrammetric workflow. Data‐sets from two case‐studies provided a variety of source data and hence a good opportunity to evaluate the influence of the quality of archival material on the accuracy of coordinated points. Based on the statistical weights assigned to the measurements, precision of the data was estimated a priori, while residuals of independent checkpoints provided an a posteriori measure of data accuracy. Systematic discrepancies between the two values indicated that the routinely used stochastic model was incorrect and overoptimistic. Optimized weighting factors appeared significantly larger than previously used (and accepted) values. A test of repeat measurements explained the large uncertainties associated with the use of natural objects for ground control. This showed that the random errors not only appeared to be much larger than values accepted for appropriately controlled and targeted photogrammetric networks, but also small undetected gross errors were induced through the ‘misidentification’ of points. It is suggested that the effects of such ‘misidentifications’ should be reflected in the stochastic model through selection of more realistic weighting factors of both image and ground measurements. Using the optimized weighting factors, the accuracy of derived data can now be more truly estimated, allowing the suitability of the imagery to be judged before purchase and processing. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

一种改进的斜支撑体系支护某超大深基坑的变形分析     

刘裕华  陈征宙  毕港 《地震学刊》2011,(1):38-43

济南某商业广场超过50000 m^2的基坑采用一种改进的斜支撑支护体系进行支护,与普通斜支撑支护型式不同,该支护体系包括支护桩、斜撑、立柱与支撑桩。本文采用FLAC^3D显式有限差分数值计算分析方法,并结合支护桩水平位移测斜数据,对该支护体系的变形特性进行分析研究,从中论证各支护单元在3个开挖阶段的运动学效应。研究结果表明,该斜支撑支护体系可以把各支护单元以及它们之间的土体充分调动起来,相互之间积极协调,以抵挡基坑开挖带来的土压力,从而减小基坑周围土体位移,保障周围道路、地下设施及周边建筑的正常运行。  相似文献   

近景摄影测量中系列图件的测绘方法     

张振文 《测绘学院学报》1995,(2)

本文探讨了在近景摄影测量中最佳摄影参数的确定方法，在总结多年来实际作业经验的基础上，介绍了断面图、立面图、等值线图和斜视图的测绘方法。  相似文献   

南天山古生代板块构造演化   总被引：38，自引：4，他引：38       下载免费PDF全文

蔡东升  卢华复 《地质论评》1995,41(5):432-443

据南天山古生物地层、古地磁、岩石地球化学和同位素年龄等资料的综合分析结果；认为该区在奥陶纪－二叠纪曾为古大洋。最初裂开为大洋是以震旦纪贝义西组大陆裂谷火山喷发为标志，从晨旦纪－奥陶纪完成了从裂谷到被动大陆边缘海盆的演化；志留纪－泥盆纪南天山洋壳向哈萨克斯坦板块之下俯冲，泥盆纪末至石炭纪早期，塔里木板块与哈萨克斯坦板块发生陆－陆碰撞。石炭纪－早二叠纪在南天山仍存在一个向西开口的前陆残余海盆。它最终关  相似文献   

航测大比例尺数字化测图中的若干问题   总被引：1，自引：1，他引：1  

王佩军  李宏 《测绘信息与工程》2001,(1):7-10

在航测全数字化测图软件还比较昂贵的情况下，立足现有高备，运用测绘新技术，进行大比例尺航测数字化成因，获取数字地图，为城市地理信息系统提供基础信息，对中小城市的测绘工作是一种较好的选择。  相似文献   

JX-4A全数字摄影测量系统测制大比例尺地形图   总被引：2，自引：0，他引：2  

徐亚明  卫军  吴浩  花向红  王佩军 《测绘信息与工程》2001,(3):34-37

介绍了全数字摄影测量系统，并以JX－4A数字摄影测量工作站为例，介绍了全数字测图的的方法和应该解决的几个问题，最后辅以实例探讨了大比例尺测图精度及检测方法。  相似文献   

Measuring Flume Surfaces for Hydraulics Research Using a Kodak DCS460     

Jim H. Chandler  Koji Shiono  Ponnambalam Rameshwaren  & Stuart N. Lane 《The Photogrammetric Record》2001,17(97):39-61

A critical problem in hydraulics research is accurate measurement of fluvially worked sediments, both in the field and in scaled representations of field situations in laboratory flumes. Such measurement must provide information on individual grain characteristics, and their organisation into structures referred to as bedforms. Existing measurement approaches are based upon mechanical or laser profiling devices, which are both expensive and take considerable time to acquire data, particularly where information is required at very high densities. This paper demonstrates how conventional automated terrain model extraction software, combined with image acquisition using a Kodak DCS460 digital camera, has been effective in generating digital elevation models of complex bed morphology. This has reduced time spent collecting data in the flume and has allowed data collection at much higher spatial and temporal densities. Application of the method is illustrated by research carried out at Hydraulics Research Wallingford. Issues discussed include configuration of photographs and control coordinates; appropriate camera calibration methods; stability of inner orientation of the Kodak DCS460; and accuracies obtained. Comparisons with independent check data reveal that accuracies of ±2.5mm have been achieved using a camera-to-object distance of 4.2 m.  相似文献   

Book Reviews     

《The Photogrammetric Record》2001,17(97):177-199

Books reviewed:
M. Petrou and P. Bosdogianni, Image Processing, The Fundamentals
S. N. Lane, K. S. Richards and J. H. Chandler, Landform Monitoring, Modelling And Analysis
T. M. Lillesand and R. W. Kiefer, Remote Sensing And Image Interpretation
A. S. Câmara and J. Raper, Spatial Multimedia And Virtual Reality
M. N. Demers, Fundamentals Of Geographic Information Systems
J. L. Casanova, Remote Sensing In The 21st Century: Economic And Environmental Applications
G. McGrath and L. M. Sebert, Mapping A Northern Land: The Survey Of Canada
A. S. Milman, Mathematical Principles Of Remote Sensing: Making Inferences From Noisy Data
K. Kraus, Photogrammetrie Band 3: Topographische Informations-systeme
E. M. João, Causes And Consequences Of Map Generalisation
R. B. Parry and C. R. Perkins, World Mapping Today
P. M. Mather, Computer Processing Of Remotely Sensed Images: An Introduction
M. E. Schaepman, Calibration Of A Field Spectroradiometer
J. C. Iliffe, Datums And Map Projections For Remote Sensing, Gis And Surveying  相似文献