海量三维地质空间数据的自适应预调度方法

针对大规模三维地质空间数据实时应用中的高效调度难题,采用空间聚类和空间插值理论,将缓存中的空间对象视为样品数据,将这些对象的命中率作为估值权值,将空间索引中的空间对象信息当作待估值数据,兼顾系统的内存容量和CPU的计算能力,设计实现了海量三维地质空间数据的自适应预调度算法。实验结果证明了该方法的正确性和有效性。     

QUALITY ASSESSMENT OF DIGITAL ELEVATION MODELS PRODUCED BY AUTOMATIC STEREOMATCHERS FROM SPOT IMAGE PAIRS

A number of published steromatching algorithms have been implemented and tested on SPOT images of areas for which gridded digital elevation models (DEMs) are available with spacings of 80 m or less, as well as ground control checkpoints. Results are presented for comparison of stereomatched output with the DEMs as well as an analysis of the errors arising and their causes. Results are discussed for planimetrically geocoded and epipolar resampled data. An error budget describing effects due to orientation, feature localisation and matching are discussed and conclusions drawn for future work in this area.     

基于POI数据的模糊地名空间范围估计

在信息检索中常用地名作为空间参照,因此确定模糊地名的空间范围备受关注。由于模糊地名不存在确切的边界,评估模糊地名空间范围十分困难,但人们对模糊地名的认知区域可以提供参考。本文分析了模糊地名空间的基本特征;以案例形式,讨论了利用POI数据和认知实验确定模糊地名空间范围的基本方法和特点,并分析这些案例地名空间的特性。从这些案例研究可以得出以下结论:影响模糊地名空间范围的因素有道路、熟悉程度和地名借用;用POI数据对模糊地名估计出的空间范围符合人们认知的空间范围。     

武汉地区断裂构造研究

本文运用数字图象处理技术,统计分析方法、构造地质、地震地质等多种定量、定性分析方法对武汉地区断裂构造特征及其与地震活动性的关系进行了深入研究。文中编制了断裂构造系列等密度图,指出了断裂构造的网络特征,进而对隐伏断裂进行了讨论,首次提出了汉阳——梁子湖北西向隐伏断裂的概念,最后对断裂构造与地震活动的关系进行了探讨。     

整体大地测量的确定性参数模型

本文将整体大地测量各类观测方程中作为随机信号的重力场参数（ΔN，ξ，η）均表达为重力异常Δg的泛函，又引入Δg的B样条函数并以样条系数C_(11)作待定参数，提出一种整体大地测量的确定性参数模型，给出了相应系数矩阵的表达式和算法，最后对该模型的求解问题作了说明。     

基于俯仰轴相交和球拟合的天线旋转中心测量方法

针对传统天线旋转中心测量时,俯仰轴生成方式不严密对其精度和可靠性产生不利影响的问题,提出了俯仰轴相交和球拟合两种新的旋转中心测量方法。对不同方位下标志点绕俯仰轴的运动轨迹进行圆拟合,得到含有方位信息的俯仰轴,多条俯仰轴求交点作为旋转中心,称之为俯仰轴相交法,较传统方法可靠性更高。对标志点的运动轨迹进行球拟合,取所有球心的均值作为旋转中心,称之为球拟合法,避免了圆拟合及求交点的过程,方法更为严密。以3台φ3 m上行阵天线为实验对象,应用全站仪和工业摄影测量技术获取标志点在规划姿态下的坐标,采用两种新方法处理观测数据,均得到了内符合精度达亚毫米级的旋转中心。     

Numerical calculation of weakly singular surface integrals

We consider semi-analytical and purely numerical integration methods for weakly singular integrals with point singularities on curved smooth surfaces. The methods can be applied to many practical computations in Geodesy, e.g. terrain corrections, Stokes' and Hotines' integral, surface potentials, and the solution of geodetic boundary value problems using integral equations. Current numerical integration techniques are reviewed. The most important semi-analytical and purely numerical techniques are described. Test calcualtions are done and the techniques are compared as regards accuracy and computational efficiency. Semi-analytical methods, which are based on some regularizing parameter transformations, are superior to purely numerical techniques. The best choice are modified polar coordinates defined in the parameter domain with the singularity as pole. Triangular coordinates show similar performance if carefully tuned. Extrapolation techniques and adaptive subdivision techniques behave poorly as regards accuracy and numerical efficiency. Standard integration techniques, which ignore the singularity, completely fail.     

GIS地理空间数据共享的探讨

本文在论述现有的几种实现空间数据共享的技术模式的基础上,分别评价了各个模式的优缺点,针对当今数据共享所面临的困难提出了解决这些问题的建议以及几种长期和短期解决方案,最后本文对数据共享的发展趋势及其解决方案进行了展望。     

A method for analyzing the expansion and shrinkage of point pattern

This article proposes a new method for analyzing the spatial expansion and shrinkage of point patterns. Spatial expansions of epidemic diseases and market areas are represented as the expansions of point patterns when disease cases and store customers are represented as points. The spatial expansion and shrinkage have been studied in many scientific fields. Existing analytical methods, however, are not sufficient for treating complicated spatiotemporal patterns. To answer this demand, this article develops a new method for analyzing the expansion and shrinkage of points. Three vector measures evaluate the degree and direction of expansion and shrinkage as functions of location and time. They are visualized as vector maps, which are valid for capturing the global spatiotemporal pattern as well as for discussing the local variation. Summary measures of these vectors allow us to grasp the overall spatiotemporal pattern efficiently. To test the validity of the proposed method, this article applies it to the analysis of visitors to Shinjuku and Ginza in Tokyo. The proposed measures permitted us to evaluate the spatiotemporal pattern of the visitors in detail and to consider its underlying structure from various perspectives, which indicated the soundness of the technique.     

卫星重力场探测及空间和地面大地测量联合观测

国际大地测量与地球物理联合会(IUGG)第廿四届大会于2007年7月上旬在意大利举行,本文结合这次大会对重力卫星CHAMP、GRACE和GOCE的目前概况作简要介绍,对它们在探测地球重力场方面的进展进行了评述。对国际大地测量协会(IAG)提出的"全球大地测量观测系统GGOS"和"整合空间大地测量技术作为全球大地测量和地球物理观测系统的基础GGOS-D"项目中"共点"测量的重要性进行了评述,并对这类共点测量成果解算应注意事项进行了介绍。最后将国际大地测量与地球物理联合会(IUGG)主席和秘书长在第廿四届大会开幕式上的报告和答记者问摘编后作为本文附录供参考。     

Formal definition of a user-adaptive and length-optimal routing graph for complex indoor environments

Car routing solutions are omnipresent and solutions for pedestrians also exist. Furthermore, public or commercial buildings are getting bigger and the complexity of their internal structure has increased. Consequently, the need for indoor routing solutions has emerged. Some prototypes are available, but they still lack semantically-enriched modelling (e.g., access constraints, labels, etc.) and are not suitable for providing user-adaptive length-optimal routing in complex buildings. Previous approaches consider simple rooms, concave rooms, and corridors, but important characteristics such as distinct areas in huge rooms and solid obstacles inside rooms are not considered at all, although such details can increase navigation accuracy. By formally defining a weighted indoor routing graph, it is possible to create a detailed and user-adaptive model for route computation. The defined graph also contains semantic information such as room labels, door accessibility constraints, etc. Furthermore, one-way paths inside buildings are considered, as well as three-dimensional building parts, e.g., elevators or stairways. A hierarchical structure is also possible with the presented graph model.     

引入灭点约束的TSAI两步法相机标定改进研究

针对TASI两步法相机标定过程无法求解相机主点位置的问题,引入灭点几何约束进行改进,推导并建立了平面格网上两组正交直线透视投影形成的双灭点与相机内参数以及TASI两步法相机标定过程参数间的严格数学关系,详细阐述了综合运用双灭点与径向准直约束计算相机内参数的迭代过程,并以此为基础,给出了相机外方位参数以及径向畸变参数的求解步骤。实验结果验证了该改进方法的有效性。     

高速公路勘测定界的的方法研究

本文扼要阐述公路勘测定界测绘与其土地报批图件资料制作过程,借用现有商业软件南方"CASS成图系统"和办公系统软件微软"Microsoft Office Excel",成图、制表及图件资料涉及内容,提出应注意问题及建议。     

测绘装备超前标准化初探

本文简要介绍超前标准化的概念及作用，分析测绘标准化现状和实施超前超前标准化的必要性，提出实施测绘超前标准化的几点建议。     

城市遥感的特点及技术要求

由于城市具有典型的非均质性及构成城市的要素较小, 因此, 城市生态系统遥感与自然生态 系统遥感有显着的差异。本文讨论了影响城市遥感诸因素, 如人工物质的光谱特性、混合像元、 霾因子、边缘锐度及摄影死角等问题, 此外, 就传感器、像片比例尺、分辨率、旁向重叠率、时相 等的选择原则也作了论证。     

Rational function optimization using genetic algorithms

In the absence of either satellite ephemeris information or camera model, rational functions are introduced by many investigators as mathematical model for image to ground coordinate system transformation. The dependency of this method on many ground control points (GCPs), numerical complexity, particularly terms selection, can be regarded as the most known disadvantages of rational functions. This paper presents a mathematical solution to overcome these problems. Genetic algorithms are used as an intelligent method for optimum rational function terms selection. The results from an experimental test carried out over a test field in Iran are presented as utilizing an IKONOS Geo image. Different numbers of GCPs are fed through a variety of genetic algorithms (GAs) with different control parameter settings. Some initial constraints are introduced to make the process stable and fast. The residual errors at independent check points proved that sub-pixel accuracies can be achieved even when only seven and five GCPs are used. GAs could select rational function terms in such a way that numerical problems are avoided without the need to normalize image and ground coordinates.     

Some properties of decorrelation techniques in the ambiguity space

The most recent contributions to ambiguity resolution techniques have mainly focused on resolution in the ambiguity domain. Two techniques utilizing a decorrelation approach are compared. These techniques are the least-squares ambiguity decorrelation adjustment method and the lattice basis reduction. The latter is also known as the LLL method. The main focus in this article is on the decorrelation performance of these state-of-the-art techniques, which are aiming at ambiguity space decorrelation through unimodular transformations. The performances of the two-decorrelation techniques are compared through their ability in making the ambiguity space as orthogonal as possible.     

基于GIS的奥运场馆消防灭火数字预案系统

分析了奥运场馆消防灭火数字预案系统的体系结构和数据库设计,阐述了系统的关键技术,即组件式GIS、火灾模型与GIS集成和模型的GIS表达,实现了火灾接警定位、火灾模拟与评估以及应急处置等功能.     

结合多尺度几何分析和KICA的遥感图像变化检测

为了进一步提高基于独立分量分析ICA(Independent Component Analysis)的遥感图像变化检测精确度,更好地实现地表覆盖的动态监测,将多尺度几何分析和核独立分量分析KICA(Kernel Independent Component Analysis)相结合应用于遥感图像的地表覆盖变化检测。首先利用Contourlet变换、复Contourlet变换CCT(Complex Contourlet Transform)、非下采样Contourlet变换NSCT(Nonsubsampled Contourlet Transform)等多尺度几何分析对土地遥感图像进行多尺度分解;然后对分解后的数据进行核独立分量分析,通过核函数将数据映射到高维特征空间中,再在该空间中用ICA方法分离出互相独立的分量;最后将分离后的地表变化分量转化为图像分量,再采用最大类间方差法对变化图像进行分割,实现地表覆盖的变化检测。给出了本文方法和近年来提出的基于ICA、基于KICA、基于小波变换和ICA等变化检测方法的实验结果,并进行了分析和定量比较。实验结果表明,基于多尺度几何分析和KICA的变化检测方法能更好地分离出遥感图像的变化信息,其中基于NSCT和KICA方法的错判和漏检误差最小,且在边缘细节方面处理得更好,而基于Contourlet变换和KICA方法的检测效率相对较高。     

两种不同的SVM建模方法在大坝变形预测中的应用

用支持向量机对大坝变形监测数据建模分析和预测一般有两种方法:一是仅用大坝的变形数据作为输入端和输出端,构建支持向量机模型;二是用温度、水压等大坝变形的影响因子作为输入端,大坝变形数据作为输出端,构建支持向量机模型。两种建模方法比较研究鲜有讨论,文中用这两种建模方法对福建省某一大坝进行建模预测。结果表明,第二种方法建模预测速度更快,预测精度更高。