城市地图数据库面实体匹配技术

同一地区不同来源地图数据库同名面实体的识别或匹配对空间数据库的集成与信息共享非常有意义。该文研究了城市地图数据库同名面实体匹配的有关问题 ,提出了基于模糊拓扑关系分类的面实体匹配方法 ,该方法充分考虑了源地图数据库的不确定性 ,能处理非一对一的匹配情况。匹配结果不仅可以作为城市地图数据库集成和信息共享的依据 ,还可以用来分析两个地图数据库之间的差异 ,进行变化检测与自动更新     

Photogrammetric Reconstruction of the Great Buddha of Bamiyan, Afghanistan

In the valley of Bamiyan, Afghanistan, approximately 1700 years ago, two large standing Buddha statues were carved out of the sedimentary rock of the region. They were 53 and 38 m high and the larger one figured as the tallest representation of a standing Buddha in the world. In March 2001 the Taleban government militia demolished the colossal statues. After the destruction a group from ETH Zürich completed the computer reconstruction of the Great Buddha, which can serve as the basis for a physical reconstruction. This paper reports the results of the image-based 3D reconstruction of the statue, performed on three different data-sets in parallel and using different photogrammetric techniques and algorithms.     

基于相对定向结果和多视几何约束的序列影像直线相关研究

以对序列影像进行连续像对相对定向的结果 (自由网相机参数和部分同名像点 )为基础 ,对VIDEO序列影像的直线相关问题进行了研究 ,提出并实现了相关的算法 ,给出了在具体实践中的应用效果。     

一种高精度的工业钣金件图像直线提取算法

研究应用一种高精度的工业钣金件图像直线提取算法在工业测量中的应用,该算法采用设计好的基本模型库,经过人机交互获得初值,然后进行最小二乘模板匹配提取工件边缘直线。     

Rational function model-based image matching for digital elevation models

This paper presents an image matching technique for IKONOS satellite imagery based on rational function models (RFMs). This algorithm adopts the object-space approach and reduces the search space to within the confined line-shaped area called the piecewise matching line (PML). Also, the detailed procedure of generating 3D surface information using the RFM coefficients (RFCs) is introduced to illustrate an end-user's point of view. The final digital elevation model (DEM) generated using the proposed scheme shows a mean error of 2·2 m and rmse of 3·8 m compared with that from a 1:5000 scale digital map.     

Effects of jpeg 2000 compression on automated dsm extraction: evidence from aerial photographs

This paper evaluates the effects of JPEG 2000 compression on automated digital surface model (DSM) extraction, using the area-based matching technique. Two stereopairs of aerial photographs, which have different photo scale, pixel size, and topographic type, are used as the images for the experiments. In the experiments, the DSM generated from the uncompressed image is set as the reference, and the elevation accuracy is computed for a range of compression ratios (2:1 to 100:1). The results show that the employed indices of image quality based on the JPEG 2000 compression are clearly superior to the commonly used JPEG compression technique—especially for high compression ratios. However, the elevation accuracy varies with the compression ratios. Also, JPEG 2000 compression does not have a significant influence on the percentage of the successful matching rate. In addition, a near linear fall-off is observed in extracted DSM accuracy with increasing compression ratios.     

1：50万数字航空图质量检查软件设计

1：50万数字航空图生产及建库已全面启动。本文介绍了航空图的特点，根据生产实际重点论述了数字航空图质量检查软件MapCheck50的设计原理、采用的技术方法。     

Spot Revisited: Accuracy Assessment, Dem Generation and Validation from Stereo Spot 5 Hrg Images

SPOT 5 HRG Level 1A and 1B stereo scenes covering Zonguldak testfield in north-west Turkey have been analysed. They comprise the left and right image components with base to height ratio of 0·54. The pixel size on the ground is 5 m. The bundle orientation was executed by the PCI Geomatica V9.1.4 software package and resulted in 3D geopositioning to sub-pixel accuracies in each axis provided that at least six control points were used in the computation. Root mean square error (rmse) values and vectors of residual errors for Levels 1A and 1B are similar, even for different control and check point configurations. Based on the scene orientation, Level 1A and 1B digital elevation models (DEMs) of the testfield have been determined by automatic matching and validated by the reference DEM digitised from the 1:25 000 scale topographic maps, interferometric DEMs from Shuttle Radar Topography Mission (SRTM) X- and C-band SAR data and the GPS profiles measured along the main roads in the testfield. Although the accuracies of reference data-sets are too similar to the generated SPOT DEMs, these are the only high quality reference materials available in this area. Sub-pixel height accuracy was indicated by the comparison with profile points. However, they are in favourable locations where matching is always successful, so such a result may give a biased measure of the accuracy of the corresponding DEMs.     

岩土压力传感器静区配问题的研究进展

简要介绍了岩土压力传感器静匹配方面的研究进展,导出了匹配误差的近似解析理论公式和统一的定量计算公式;给出了最佳压陷位移系数的量值;建立了2个匹配条件之间的定量关系;给出了传感器承压面和周围介质中应力场的分布规律。     

GIS空间数据采集中概率松弛与神经网络的组合模型

本文介绍一种ＧＩＳ空间数据采集中概率松弛与神经网络的组合模型，该模型用于地图分色和立体影像的整体匹配。