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基于DEM的机助航空摄影技术设计(英文) 总被引：1，自引：0，他引：1
In aerial photography, the primary factor is terrain undulation. However, most of the external aerial photography software used for aerial photography design do not take terrain undulation influence into consideration. Therefore, the design result has comparative randomicity and ＂gaps＂ are expected. An aerial photography design system is developed by analyzing the terrain undulation influence to the design result with DEM data so that the forward overlap and side overlap can be justified according to the block terrain undulation to meet specifications or standards. The data designed by this system is compared with the real flying data. The results show that making use of DEM to assist in aerial photography design can ensure that the designed result fits the real terrain better. 相似文献
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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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A case study of using external DEM in InSAR DEM generation 总被引：2，自引：0，他引：2
ZHOUChunxia GELinlin EDongchen CHANGHsingchung 《地球空间信息科学学报》2005,8(1):14-18
Synthetic aperture radar interferometry (InSAR) has been used as an innovative technique for digital elevation model (DEM) and topographic map generation. In this paper, external DEMs are used for InSAR DEM generation to reduce the errors in data processing. The DEMs generated from repeat-pass InSAR are compared. For steep slopes and severe changes in topography, phase unwrapping quality can be improved by subtracting the phase calculated from an external DEM. It is affirmative that the absolute height accuracy of the InSAR DEM is improved by using external DEM. The data processing was undertaken without the use of ground control points and other manual operation. 相似文献
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YU Xuexiang associate professor Ph.D Department of Resource Environment Engineering Anhui University of Science Technology Huainan China. XU Shaoquan GAO Wei LU Weicai 《地球空间信息科学学报》2003,6(4):51-56
A new similar singledifference mathematical model ( SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. In order to validate the correctness and the accuracy of the similar single-difference model, the test with five dual frequency receivers is carried out on a slideway which moved in plane in Feb. 2001. In the test, five sessions are observed. The numerical results of test data show that the advanced model is correct. 相似文献
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JINBaoxuan BIANFuling ZUOXiaoqing WANGFangxiong 《地球空间信息科学学报》2005,8(2):115-121
With the rapid development of computer graphics, distributed-computing and Internet, it is possible to achieve Internet-based virtual city. This paper dwells on the method of the terrain and its feature modeling and complex entity modeling in the virtual city. Then, discusses the method for Internet-based virtual city 3D visualization and the design of the Browser/Server architecture of the system of virtual city in the network environment. Finally, Java and Java 3D are used to show an experiment example, and the related conclusion about Internet-based virtual city 3D displaying and the client-side interactive operation is given. 相似文献
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LI Zhicai XU Caijun 《地球空间信息科学学报》2005,8(3):225-229
On the basis of the dislocation theory and gravity observation, a joint inversion model is presented with a fitting factor A scaling amplitudes between the gravity and GPS observation data. The test results show that the new joint model is better than that taking the scale factor ）, as a constant from the inversion result of MSE （mean square error）. In addition, the random cost method used in the inversion algorithm is revised and improved, which shows that the improved random cost method can easily get the local minimum value and greatly decrease the iteration steps. 相似文献
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Classification is always the key point in the field of remote sensing. Fuzzy c-Means is a traditional clustering algorithm that has been widely used in fuzzy clustering. However, this algorithm usually has some weaknesses, such as the problems of falling into a local minimum, and it needs much time to accomplish the classification for a large number of data. In order to overcome these shortcomings and increase the classification accuracy, Gustafson-Kessel （GK） and Gath-Geva （GG） algorithms are proposed to improve the traditional FCM algorithm which adopts Euclidean distance norm in this paper. The experimental result shows that these two methods are able to detect clusters of varying shapes, sizes and densities which FCM cannot do. Moreover, they can improve the classification accuracy of remote sensing images. 相似文献
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The characteristics of three GPS kinematic data processing models, Least Squares （LS）, Kalman filtering and filtering are discussed and their advantages and disadvantages are compared. With observational data and pertinent data processing software, the applicable condition, context and effect of the three models are experimented. Results show that when the mobile platform is in uniform motion, the accuracy of the three models are almost equal; when the mobile platform is in stochastic acceleration, the accuracy of H∞ filtering model is superior to that of LS, while that of Kalman filtering is the worst. 相似文献
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The basic principle of interval arithmetic and the basic algorithm of the interval Newton methods are introduced.The prototype algorithm can not find any zero in an interval that has zero sometimes,that is ,it is instable.So the prototype relaxation procedure is improved in this paper.Additionally,an immediate test of the existence of a solution following branch-and-bound is proposed,which avoids unwanted computations in those intervals that have no solution.The numerical results demonstrat that the improved interval Newton method is superior to prototype algorithm in terms of solution quality,stability and convergent speed. 相似文献
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SHIWenzhong AhmedShaker 《地球空间信息科学学报》2004,7(1):24-30
The exploitation of different non-rigorous mathematical models as opposed to the satellite rigorous models is discussed for geometric corrections and topographic/thematic maps production of high-resolution satellite imagery (HRSI). Furthermore, this paper focuses on the effects of the number of GCPs and the terrain elevation difference within the area covered by the images on the obtained ground points accuracy. From the research, it is obviously found that non-rigorous orientation and triangulation models can be used successfully in most cases for 2D rectification and 3D ground points determination without a camera model or the satellite ephemeris data. In addition, the accuracy up to the sub-pixel level in plane and about one pixel in elevation can be achieved with a modest number of GCPs. 相似文献
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结合空间数据库、GIS、计算机图形学、RS等技术构建了虚拟现实地理信息系统。通过研究地形数据的生成及空间数据库的存储管理,实现了遥感影像的自动配准及无缝拼接;基于四叉树的LOD算法、地形节点评价系统、动态调度及大规模纹理映射等技术的研究,实现了地形数据的3维可视化;提出了自适应特征数据覆盖渲染算法,将2维GIS特征数据覆盖叠加到所创建的3维模型上,构建了虚拟现实环境。该系统成功应用于胜利油田,实现了地下油田的虚拟现实3维可视化,具有一定的理论价值和现实意义。 相似文献
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针对基于面模型的战场地形要素建模与可视化的不足,提出利用体素模型实现战场环境地形要素的建模与可视化方法和基本思路。对基于特征点的双重移动立方体算法进行改进,实现体素地形的可视化表达,引入体素地形可视化的影响因子便于对体素地形可视化效果的控制,通过实验进行分析,得出最佳取值空间。 相似文献
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地形可视化中快速视区裁剪算法研究 总被引：6，自引：0，他引：6
讨论了地形可视化中的视区裁剪技术，分析了多种可能的改进方法，并实现了一种基于层次包围球的快速视区裁剪算法。该算法可以十分快速和准确地判断地形渲染过程中节点和视区的相互位置关系，大大减轻图形系统的负担，有效地提高地形渲染的速度。 相似文献
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三维可视化技术的发展日益成熟,本文以ERDAS IMAGINE软件为基础,利用Arc GIS软件将该地形图的高程数据转换为高精度的数字高程模型,通过影像的几何校正后,将DEM影像与该区域的多光谱影像图进行叠加,从而实现了三维地形的可视化。几何校正后的三维地形真实感更强,并在此基础上分析了三维地形可视化的应用,对于虚拟现实技术的迅速发展有着重要的意义。 相似文献
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大规模海量三维模型数据网络传输和终端可视化是面向Web的三维GIS应用关键技术。本文提出将三维模型自适应面删除简化算法和地形模型单面片自动生成算法相结合，实现大批量构建面简化LOD （层次细节模型）模型库自动建库，有效解决了海量高精度、大范围三维模型面向Web的三维GIS应用问题。研究成果在天津市网络三维数字城市规划管理系统项目中成功进行试验，效果显著。 相似文献
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介绍了将多源遥感影像数据应用于战场环境可视化之前的主要预处理方法,如影像金字塔生成、纹理数据结构准备、纹理快速调用等.该过程中所用到的小波变换、四叉树数据结构与细节层次算法等关键技术,能够有效地提高战场建模的真实感和效率. 相似文献