共查询到20条相似文献，搜索用时 765 毫秒
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LIPingxiang YUJie BIANFuling 《地球空间信息科学学报》2005,8(1):23-27
This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane. After the method, aerial images match known DEM to capture the spatial position and posture. Some aerial images and terrain data are used to testify our method. Compared with those of analytic and stereo mappers, the results by our method are correspondent to real measurements well. 相似文献
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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
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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
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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
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DEM Compression Based on Integer Wavelet Transform 总被引：1，自引：0，他引：1
CHEN Renxi LI Xinhui 《地球空间信息科学学报》2007,10(2):133-136
DEM data is an important component of spatial database in GIS. The data volume is so huge that compression is necessary. Wavelet transform has many advantages and has become a trend in data compression. Considering the simplicity and high efficiency of the compression system, integer wavelet transform is applied to DEM and a simple coding algorithm with high efficiency is introduced. Experiments on a variety of DEM are carried out and some useful rules are presented at the end of this paper. 相似文献
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《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
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空间数据模糊聚类的有效性(英文) 总被引：1，自引：0，他引：1
The validity measurement of fuzzy clustering is a key problem. If clustering is formed, it needs a kind of machine to verify its validity. To make mining more accountable, comprehensible and with a usable spatial pattern, it is necessary to first detect whether the data set has a clustered structure or not before clustering. This paper discusses a detection method for clustered patterns and a fuzzy clustering algorithm, and studies the validity function of the result produced by fuzzy clustering based on two aspects, which reflect the uncertainty of classification during fuzzy partition and spatial location features of spatial data, and proposes a new validity function of fuzzy clustering for spatial data. The experimental result indicates that the new validity function can accurately measure the validity of the results of fuzzy clustering. Especially, for the result of fuzzy clustering of spatial data, it is robust and its classification result is better when compared to other indices. 相似文献
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Algorithm for generating dem based on cone 总被引：1，自引：0，他引：1
JIANG Hongfei 《地球空间信息科学学报》2000,3(3):30-33
Digital elevation model (DEM) has a variety of applications in GIS and CAD.It is the basic model for generating three-dimensional terrain feature.Generally speaking,there are two methods for building DEM.One is based upon the digital terrain model of discrete points,and is characterized by fast speed and low precision.The other is based upon triangular digital terrain model,and slow speed and high precision are the features of the method.Combining the advantages of the two methods,an algorithm for generating DEM with discrete points is presented in this paper.When interpolating elevation,this method can create a triangle which includes interpolating point and the elevation of the interpolating point can be obtained from the triangle.The method has the advantage of fast speed,high precision and less memory. 相似文献
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The capability of humancomputer interaction reflects the intelligent degree of mobile navigation system.The navigation data and functions of mobile navigation system are divided into system commands and non-system commands in this paper,And then a group of speech commands are abstracted.This paper applies speech recognition technology to intelligent mobile navigation system to process speech commands and does some deep research on the integration of speech recognition technology with mobile navigation system.The navigation operation can be performed by speech commands,which makes humancomputer interaction easy during navigation.Speech command interface of navigation system is implemented by Dutty Software,which is based on speech recognition system-Via Voice of IBM.Through navigation experiments,navigation can be done almost without keyboard,which proved that human-computer interaction is very convenient by speech commands and the reliability is also higher. 相似文献
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The coherence coefficient map and residue guided least square phase unwrapping algorithm 总被引：1，自引：0，他引：1
ZHANG LiLIAO MingshengZHANG ZuxunZHANG Yong ZHANG Li Doctoral Candidate 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):55-62
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使用无人机实施测绘航空摄影时，由于无人机相对航高较低，地面起伏会对无人机影像的分辨率、覆盖范围、重叠度造成较大的影响，影像成果会出现分辨率不足、重叠度不够、覆盖漏洞等缺陷。针对这一情况，本文提出了一种利用数字微分正解法的计算方法，借助DEM准确计算每张影像的覆盖范围，并使用FME软件高效生成全部影像的覆盖范围。经过实际使用，验证了该方法可以在航线设计阶段准确预测并分析全部影像的覆盖范围、重叠度，因此可及时发现设计问题并调整航线。该方法可以有效减少因地形起伏造成的影像覆盖缺陷，减少返工现象，从整体上提高了作业效率。 相似文献
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本文对倾斜航空摄影的关键技术进行了研究，将倾斜航空摄影技术引入矿山地质环境调查领域，通过倾斜航空摄影设备获取了目标区域多视角航空影像，基于立体像对制作了DOM和高精度的DEM，并利用像片控制点成果和航空摄影系统POS数据，制作出高精度的实景三维地形模型，基于Skyline平台进行二次开发，结合矿山历史遥感监测及地质灾害隐患数据，完成了数据库的建立以及矿山地质环境管理系统的建设。主要包括实景三维环境下的矿点及地质灾害隐患点查询、修改、统计、分析等功能。结果分析得出，采用倾斜航空摄影技术生产传统4D产品和实景三维模型，具有周期短、信息多元化的特点，极大地减少了外业核查劳动强度，能更好地满足矿山地质环境监测管理的需求。 相似文献
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长期以来,航空摄影一直是获取基础地理信息的主要手段之一。航空摄影是一项多组织、多工序协调作业的综合性系统工程,不仅涉及飞行摄影,而且包括技术性很强的规划设计工作。本文针对当前国内航空摄影工作和规划设计的现状,在吸取国内外相关软件的先进理念和技术成果的基础上,通过分析地形起伏对像片重叠度的影响,对航空摄影工作的航线规划设计等核心技术内容展开讨论和研究,旨在研发一套能消除地形起伏对像片重叠度影响的航空摄影设计的原型系统。实验表明,该原型系统通过计算航带在实际地面的重叠度来精确调整基线,满足了重叠度的要求,较好地解决了地形起伏的问题,提高了航摄设计的效率,确保了航摄成果的质量。 相似文献
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This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane. After the method, aerial images match known DEM to capture the spatial position and posture. Some aerial images and terrain data are used to testify our method. Compared with those of analytic and stereo mappers, the results by our method are correspondent to real measurements well. 相似文献
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LI Pingxiang YU Jie BIAN FulingLI Pingxiang professor State Key Laboratory of Information Engineering in Surveying Mapping Remote Sensing Wuhan University Luoyu Road Wuhan China. 《地球空间信息科学学报》2005,8(1):23-27
1 Extraction of the steep curve mapThe steep curve is defined as connection linefrom zero cross points which are produced fromthe convolution of Laplace ( LOG) filtration toDEM. Firstly, the elevation data from DEM areprocessed with LOG convolution and zero cross.The sampling formula is 2G(i,j) =12πσ6(r2 -2σ2)e-r2/2σ2 (1)where -M≤i≤M,-M≤j≤M,r2=i2+j2; M isthe filtration radius, nearly equaling to 5.1σ2; pre diction errorσis set to 4. Suppose that e[i,j] is asmall … 相似文献
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一种新的基于矢量地图数据的地表纹理制作 总被引：1，自引：0，他引：1
主要阐述了基于矢量地图数据生成具有真实感3维地景纹理的思路和方法，详细论述了在Mapviewer和Photoshop环境下，地形背景纹理的制作，植被纹理的制作，水系纹理的制作以及其它要素纹理制作的方法，并给出了具体的实例。 相似文献
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大面积湖泊周边地势平坦,利用航空摄影等常规手段实现此类地区精细DEM生产,需要依靠外业控制和大量人工编辑,作业周期长,成本高。本文结合国家基础航空摄影项目,基于ALS60完成了鄱阳湖地区大面积机载LiDAR数据的获取及预处理,并通过地面检校和精度验证,对传感器的系统误差进行修正,在此基础上对点云数据进行精细化处理及DEM高效生产,产品精度满足测绘相关规范要求。该项目的成功开展,为基于航空新型技术手段的大面积湖泊周边等常规作业困难地区的高精度测绘提供了借鉴。 相似文献