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平面随机线元等概率密度误差模型边界包络线 总被引：1，自引：0，他引：1
线状实体误差模型包络线既是GIS位置不确定性研究的重要内容,又是GIS可视化研究的关键指标.为了充分利用计算机技术求解符合GIS精度要求的误差模型包络线,基于文献[1,2]中探讨过的等概率密度误差模型建模机理和数值算法,研究了平面随机线元等概率密度误差模型边界包络线的确定原理和计算方法,并通过实例辅以可视化分析,验证了原理的正确性和可操作性. 相似文献
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This paper systematically studies the statistical diagnosis and hypothesis testing for the semiparametric linear regression model according to the theories and methods of the statistical diagnosis and hypothesis testing for parametric regression model.Several diagnostic measures and the methods for gross error testing are derived.Especially,the global and local influence analysis of the gross error on the parameter X and the nonparameter s are discussed in detail;at the same time,the paper proves that the d... 相似文献
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This paper systematically studies the statistical diagnosis and hypothesis testing for the semiparametric linear regression model according to the theories and methods of the statistical diagnosis and hypothesis testing for parametric regression model. Several diagnostic measures and the methods for gross error testing are derived. Especially, the global and local influence analysis of the gross error on the parameter X and the nonparameter s are discussed in detail; at the same time, the paper proves that the data point deletion model is equivalent to the mean shift model for the semiparametric regression model. Finally, with one simulative computing example, some helpful conclusions are drawn. 相似文献
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In this paper, a method to detect corresponding point pairs between polygon object pairs with a string matching method based on a confidence region model of a line segment is proposed. The optimal point edit sequence to convert the contour of a target object into that of a reference object was found by the string matching method which minimizes its total error cost, and the corresponding point pairs were derived from the edit sequence. Because a significant amount of apparent positional discrepancies between corresponding objects are caused by spatial uncertainty and their confidence region models of line segments are therefore used in the above matching process, the proposed method obtained a high F-measure for finding matching pairs. We applied this method for built-up area polygon objects in a cadastral map and a topographical map. Regardless of their different mapping and representation rules and spatial uncertainties, the proposed method with a confidence level at 0.95 showed a matching result with an F-measure of 0.894. 相似文献
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本文是机器视觉参量下的三维数字摄影测量智能构像基础工作之一：成像系统位置姿态自动跟踪与精密修正,属于摄影测量与机器视觉、数字图像处理等学科交叉的摄像测量领域。针对基于目标3D模型的位姿跟踪问题开展研究,对相关研究的现状进行梳理,并提出系列位姿跟踪与模型修正方法。在完全已知目标3D精确模型的情况下,对于包含丰富直线特征的特殊目标,提出基于直线模型的目标位姿跟踪方法,实现了目标位姿参数的精确跟踪;为处理更为一般目标,利用目标的3D边缘模型,提出法向距离迭代加权最小二乘位姿估计方法及距离图迭代最小二乘位姿跟踪方法。当目标3D直线模型参数不准确时,结合光束法平差思想,提出一种针对序列图像的基于3D直线模型同时位姿跟踪与模型修正方法,联合优化求解目标位姿参数及3D直线模型参数,在模拟空间卫星目标位姿测量的仿真试验中,模型直线朝向、位置误差及目标位姿平均角度、平均位置误差分别为0.3°、3.5 mm及0.12°、20.1 mm。针对包含丰富直线特征的目标,在其3D直线模型完全未知的情况下,提出基于序列图像直线对应的目标结构重建与位姿跟踪方法,利用序列图像信息,在SFM框架下同时优化求解目标直线模型参数及位姿参数,仿真试验条件下,重建模型直线朝向、位置误差及位姿参数平均角度、平均位置误差分别约为0.4°、7.5 mm及0.16°、23.5 mm。 相似文献
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三维激光扫描技术由于可快速获取高精度、高密度点云数据，可将拟验收建筑及周边情况几乎完全无差地复制到电脑中，是规划验收测量特别是复杂建筑规划验收测量的理想方法，但是其数据处理一直是影响甚至制约其应用的瓶颈。本文简述了规划验收测量要点，以及三维激光扫描点云数据初步处理流程，并针对制作规划验收测量各类图件的不同需求，提出了分别通过直接取线、切片、投影等方法制作成果图件的工作思路及各方法的特点。但是还需研究和解决海量点云的数据处理，以及根据验收测量特点获得测量成果图件的问题。 相似文献
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针对三维流场数据可视化容易出现的显示混乱问题,提出一种三维流场可视化自适应方法。该方法引入模糊支持向量机对流场特征进行分类预处理,并提出一种改进的线积分卷积算法,该算法利用模糊支持向量机得到的隶属度自适应生成Sobol稀疏噪声,避免当噪声过于稠密时产生重叠现象,而当噪声过于稀疏时漏掉流场重要的细节信息。通过多组流场三维可视化仿真实验的比较与分析,验证了本文方法的有效性。 相似文献
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On the adjustment of combined GPS/levelling/geoid networks 总被引：12，自引：7，他引：5
A detailed treatment of adjustment problems in combined global positioning system (GPS)/levelling/geoid networks is given.
The two main types of `unknowns' in this kind of multi-data 1D networks are usually the gravimetric geoid accuracy and a 2D
spatial field that describes all the datum/systematic distortions among the available height data sets. An accurate knowledge
of the latter becomes especially important when we consider employing GPS techniques for levelling purposes with respect to
a local vertical datum. Two modelling alternatives for the correction field are presented, namely a pure deterministic parametric
model, and a hybrid deterministic and stochastic model. The concept of variance component estimation is also proposed as an
important statistical tool for assessing the actual gravimetric geoid noise level and/or testing a priori determined geoid
error models. Finally, conclusions are drawn and recommendations for further study are suggested.
Received: 9 September 1998 / Accepted: 8 June 1999 相似文献
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本文以南宁市城市3维模型防汛信息系统为例,探讨实物沙盘与3维电子地图的互动控制系统的实现方法。 相似文献
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本文以南宁市城市3维模型防汛信息系统为例，探讨实物沙盘与3维电子地图的互动控制系统的实现方法。 相似文献
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传统数字正射影像图(DOM)采用微分纠正方法消除相机倾斜与地形起伏所带来的投影误差,但会产生双重投影现象. 真数字正射影像(TDOM)可有效解决DOM的双重投影问题. 文中提出一种基于无人机影像的实景三维模型TDOM制作方法， 首先通过无人机挂载五镜头相机获取航空摄影测量影像并生成实景三维模型;然后采集实景三维模型建筑物顶部轮廓边界线,并构建其三维体模型;最后基于建筑物顶部轮廓边界线三维体模型进行遮蔽检测和遮蔽补偿生成TDOM. 以云南师范大学呈贡校区无人机影像实验数据验证了本文方法,实验表明本文的方法可作为一种生成高质量的TDOM方法. 相似文献
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提出了一种利用DOM和Li DAR点云数据的参数化建模方法,利用DOM分析地物的模型特征,通过Li DAR点云数据获取地物特征点坐标,采用特定的三角网连接方法构建出地物的三维模型,最后对模型进行贴图显示。这里所构建地物模型的方法不仅快速高效,而且自动化程度高,能够满足铁路三维GIS展示的要求;同时,由于是通过点云数据构建模型,在后期导入三维地形过程中能够大量减少安放地物模型工作。 相似文献
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Urban area building extraction is one of the most challenging problems in photogrammetry. Well-extracted buildings are needed for a variety of applications, such as cartography, building GIS databases for cities, and urban planning. This paper presents a new technique to extract 3D building wire-frames using a robust multi-image line-matching algorithm. Although one pair of images is adequate to find the 3D position of two visibly corresponding image features, it is not sufficient to solve the general building extraction problem due to obscured parts in the building. Four images are used in this research to extract the building wire-frames. First the images are segmented into regions. Regions are then classified into roof regions and non-roof regions based on their size, shape, and intensity values. The roof region boundary pixels are located and used to find the region perimeters. Region correspondence is solved in a pair-wise mode over all images using the epipolar constraint, region size, region shape, and region intensity values. Image lines within the corresponding regions are matched over all images simultaneously by first creating a plane for each region line. Planes are then intersected simultaneously and geometric consistency is used to determine acceptance or rejection. Results with high overlap and sidelap aerial images are presented and evaluated. The results show the completeness and accuracy that this method can provide for extracting complex urban buildings. The average coordinate accuracy is about 0·8 m using 1:4000 scale aerial photographs scanned at 30 μ m. Six buildings were examined; the line detection rate is 98%. 相似文献
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基于二维直接线性变换的数字相机畸变模型的建立 总被引：10，自引：3，他引：10
提出并论证了基于二维直接线性变换的畸变的校正方法。本方法特别适用于各类固态摄像机(CCD、CID、PSD)的畸变模型的建立，以补偿各类像点系统误差。 相似文献