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数字摄影测量,应用计算机技术、数字影像处理、影像匹配、模式识别等理论与方法,以计算机视觉代替人眼的立体观测,其产品与中间数据的记录以及处理的原始资料均是数字的,较之常规的(传统的)数字产品的生产方法,具有自动化程度高、速度快、成果多样化等优点。两次外业和两次内业,是∶地形图数字摄影测量的主要作业流程,第二次外业调绘作为1500数字摄影测量的主要外业工作与常规调绘方法有一定的区别。∶地形图数字摄影测量适合于1500大面积数字化测图。 相似文献
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一、引言
土地勘测中因地形条件和环境,常规控制测量如三角测量、导线测量,要求点间通视,费工费时,而且有误差累计,精度不均匀,外业中不能实时知道测量成果精度。GPS静态相对定位测量,无需点间通视,能够高精度地进行各种控制测量,但是需要定位时间长,且不能实时知道定位精度,内业解算中发现精度不合要求必须返工测量。 相似文献
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吴模勤 《华东地质学院学报》1987,(4)
本文就横向量边视差导线曲结构、外业操作步骤、内业计算方法、在地质工程测量中的使用条件、精度分忻方法、能否满足地质工程的精度要求等方面,作了详细的论述和推导。结果证明,横向量边视差导线这一特殊的测量方法,在其它控制测量困难的地区,有其独特的使用价值,为地质工程测量的控制方法,打开了一个新路子,可供地质战线上的广大测量工作者参考使用,对其它如道路、城建、永利建设等方面的测量同行们,也可根据所碰到的类似外业条件面灵活应用。 相似文献
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数字摄影测量,应用计算机技术、数字影像处理、 影像匹配、模式识别等理论与方法,以计算机视觉代替人眼的立体观测,其产品与中间数据的记录以及处理的原始资料均是数字的,较之常规的(传统的)数字产品的主要方法,具有自动化程度高、速度快、成果多样化等优点。两次作业和两次内业,是1:500地形图数字摄影测量的主要作业流程,第二次外业调绘作为数字摄影测量的主要外业工作是常规调绘方法有一定的区别。1:500地形图数字摄影测量适合于大面积数字化测图。 相似文献
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介绍了SWDC数码航摄影像的技术基础和其应用于航空摄影测量的优越性,鉴于SWDC像幅的特殊性,在保证量测精度的前提下,为减少外业作业的工作量,通过以不同基线的区域网像片控制点布设方案的精度试验,证明了控制点按照8条基线布设可满足内业生产及大比例尺地形图的需要。 相似文献
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结合具体工程实例介绍了当前城市中小河道测量工程中常见水工建(构)筑物的类型、调查量测内容及对应精度指标、外业测绘取舍及内业成图表示方法等,特别是根据实地水工建(构)筑物的规模大小、复杂程度,探讨了对其进行调查测绘的技术方法,并结合CAD绘图系统提出了相应的解决办法. 相似文献
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宋毓卿 《华北地质矿产杂志》2014,(1):86-86,90
正是因为有了永久基本农田划定工作,才使基本农田的保护制度得以完善,国民经济和农业发展所必需的耕地数量得到了切实保护。本文根据现有的研究资料和自身对这一课题的研究,从永久基本农田划定前期准备工作、外业工作阶段、内业工作阶段及成果的验收与报备进行了分析。 相似文献
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地下水污染场地的监控需要依据水文地质条件、地下水流场和溶质运移特征,利用水化学的示踪作用开展空间分析,以识别地下水和溶质运移特征。该方法具有简易和经济的优点。以台湾苗栗县某化工污染场地为例,通过对地下水中多种离子浓度的空间等值线分析及对比,判断污染物的来源和分布范围。采用离子浓度的统计特征值P95、P75、P50、P25构成的等值线,作为判断离子空间分布特征的依据,并形成离子之间对比的统一标准。所有离子都采用浓度P95等值线包围的区域作为其污染源,其它三种等值线表示可能出现的污染物扩散范围。在此基础上通过对比发现10种离子的污染源集中出现在场地一个范围内,并形成一个污染带,表明它们的来源具有密切的联系。10种离子P75等值线划出的污染物分布范围同样比较集中,但几乎都分布在污染带的南部,显示离子的迁移方向和迁移距离是一致的。根据离子空间分布的相似性将其分为三组,空间分布相似性高的离子组同时出现在一个区域的机会更多。通过多种水化学成分识别地下水流场和溶质运移特征,提高了结论的可信度,为污染物监控提供参考。 相似文献
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Michael Wiederkehr Romain Bousquet Martin A. Ziemann Alfons Berger Stefan M. Schmid 《International Journal of Earth Sciences》2011,100(5):1029-1063
This study monitors regional changes in the crystallinity of carbonaceous matter (CM) by applying Micro-Raman spectroscopy
to a total of 214 metasediment samples (largely so-called Bündnerschiefer) dominantly metamorphosed under blueschist- to amphibolite-facies
conditions. They were collected within the northeastern margin of the Lepontine dome and easterly adjacent areas of the Swiss
Central Alps. Three-dimensional mapping of isotemperature contours in map and profile views shows that the isotemperature
contours associated with the Miocene Barrow-type Lepontine metamorphic event cut across refolded nappe contacts, both along
and across strike within the northeastern margin of the Lepontine dome and adjacent areas. Further to the northeast, the isotemperature
contours reflect temperatures reached during the Late Eocene subduction-related blueschist-facies event and/or during subsequent
near-isothermal decompression; these contours appear folded by younger, large-scale post-nappe-stacking folds. A substantial
jump in the recorded maximum temperatures across the tectonic contact between the frontal Adula nappe complex and surrounding
metasediments indicates that this contact accommodated differential tectonic movement of the Adula nappe with respect to the
enveloping Bündnerschiefer after maximum temperatures were reached within the northern Adula nappe, i.e. after Late Eocene
time. 相似文献
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This paper presents an automatic quadrilateral mesh generation algorithm to provide 2-D meshes for simulating overland flow and transport problems in watershed systems. The conformal mapping method is studied deeply and specific treatment strategies are established according to the width of rivers and the area of other water storage zones. A conformity treatment method is proposed to deal with the incompatibility problems during discretizing the complex geometry with a plurality of sub-domains. This method ensures grid conformity through removing certain overlapped nodes and creating new appropriate nodes on common boundaries of the multi-domain mesh. Aiming at the undesired deviation of mesh boundaries from geometric contours, a relative position-percent interpolation method is proposed and a supplementary match method related to dead ends is presented. And, the double effects of projection and smooth for boundary nodes are achieved. An objective function method is proposed to locally optimize the degenerated quadrilaterals located on concave or large-curvature curves. In order to accommodate the need for overland simulations, the 1-D/2-D correspondence on river reaches, junctions with and without storage, ponds, lakes, dead ends and control structures is established. Finally, practical applications are provided to demonstrate the accuracy and reliability of the quadrilateral meshing algorithms proposed in this paper. 相似文献
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This article describes a method that determines the position of a point relative to a fixed boundary. Its advantage over the other existing algorithms described below is that in most cases it is necessary that only part of the algorithm be executed to determine the position of the point. A possible inconvenience of using this algorithm is that the contour boundary has to be entered as data. For problems where the boundary often changes the algorithm is not suitable in its present form. The applications envisaged here are to cases where the position of a very large number of points have to be determined relative to one fixed polygonal boundary whose shape is known in advance, for example, blanking out of contours in automatic contouring, or selecting drill holes which lie in the particular part of a mineral deposit. 相似文献
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应用AutoCAD进行地形图的计算机辅助制图能极大地提高工作效率,但因其没有根据数字地形分析(DTM模型)自动产生等高线的功能,用VBA编程技术,将外业采集的离散点通过建立三角网,在三角形边上内插等高点的方式,能在AutoCAD中实现等高线的自动绘制。 相似文献
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三维地质模型是地质调查信息表达从传统二维平面向三维空间转变的一次重大突破。中国正在开展的三维地质填图作为国家的重要基础地质调查工作部署,将调查与研究相结合,在推动三维地质建模从研究走向实践具有重大意义。三维地质填图过程中如何准确、快速地构建三维断层模型是其中的关键点及难点。通过对数字填图过程不同阶段数据源的分析,详细分析了实际材料图建立断层数据以及与野外路线数据的关系映射规则,提出并实现了由线及面的断层模型构建方法。该方法强调断层模型构建与业务流程的一致性、动态性和快速性,构建模型的数据源始于野外第一手资料,充分利用填图业务过程中不同阶段数据的关联、约束与继承关系,能够满足在填图过程中根据地质认识的深入快速、动态地重构模型的要求,同时也可根据直观的三维断层模型时时验证地质连图的合理性。算法已在实际野外三维地质填图工作进行了多次实验,获得较好的成果。实验说明,基于实际材料图的三维断层模型构建方法与实际业务过程同步,具有操作便捷性,可直接应用于三维地质填图的实际工作要求。 相似文献
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在甘肃和青海交界地区的1:257Y民和县幅、临夏市幅和定西市幅数字区域地质调查中,以“数字填图系统(RGMAP)”为平台,使用遥感ETM^+数据和地形数据对岩石地层进行了信息挖掘。数据准备主要是遥感和数字地形多源信息的提取和预处理.从数字地形图的等高线数据中提取高程,进而提取汇水网络等水文信息和地形参数。遥感数据经过地形校正、线性增强、色彩拉伸,进行空间分辨率增强,经彩色合成并结合数字高程,实现了对调查区构造-地层区划和部分岩石地层单元的识别。实践证明该项工作是地质填图的重要辅助手段。 相似文献
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Kent Mathewson 《Geoforum》2006,37(1):15-30
In his recent book Putting Science in its Place: Geographies of Scientific Knowledge (2004), David Livingstone challenges historians of geography to locate that history in space and places, as well as time. Using the national/cultural space that is Guatemala, this paper plots some of the co-ordinates, contours, and questions that such a geographic history might entail. Particular emphasis is placed on providing a first approximation of the contours the history of geographic research in, and on, Guatemala. The main focus is on the work of self-identified geographers, though many scholars in cognate fields, especially historians, archaeologists, and anthropologists have made important contributions to this history. Clear phases in this history are evident, starting in the late 19th century with the work of the German geographer Karl Sapper. North American geographers came to dominate the record in the post-WWII period. The current phase promises not only a new generation of researchers, but also new directions as well as some continuities with topics and questions with a century-old time-depth. This paper seeks to contribute to the largely inchoate project of producing histories of geography at the regional, national, and continental scales for Latin America. 相似文献