高分辨率机载SAR影像判读实验

近年来机载SAR系统在国内得到快速发展。由于SAR系统具有不同于光学传感器的成像机理,因而可以提供全新的数据获取手段和不同的地物信息。利用高分辨率机载SAR影像进行解译时必须熟悉其成像机理和图像信息特点,充分了解SAR图像解译标志的特点和各类地物的解译规律。本文以高分辨率机载SAR数据为基础,对比光学影像,从SAR成像特点和地物散射特性出发,对SAR影像进行了目视解译,分析了SAR影像在地形地物要素识别中的应用潜力。     

佛山市南海区国土资源“多图合一”的探讨

本文按“统一坐标原点、统一坐标体系、统一比例尺精度、统一数据格式”以及业务环环相扣的图形建库原则,以实践的方式探讨了国土资源管理中多图合一的可行性,并通过建立业务规则、图形规则,实现了多图合一中所有图层的互动与更新。     

建筑室内空间定位技术研究

为解决某市行政中心楼因建筑体量巨大、室内结构复杂而导致办事人员不易寻找目的地的问题,本文研究了室内空间定位搜寻方案,探讨了室内无卫星信号的定位方式。借助无线网络信号定位分析了无线网络信号传输中涉及的测距、信号滤波、空间定位等核心技术问题,并进行了试验验证,收到了良好的效果。     

用线特征摄影测量对目标体素进行量测和重建的可行性研究

本文利用线特征摄影测量方法对ＣＡＤ实体造型中体素进行自动量测与重建、借此建立ＣＡＤ与数字摄影测量的桥梁，文中提出了一种以描述体素几何元素为未知数，直接在像片线特征与物体表面之间进行匹配的线特征摄影测量模型和方法，并对其可行性进行了实验，实验结果表明：线特征摄影测量能达到立体摄影测量相同的，甚至更高的精度，从而可解决无明显目标点工点物体的自动量测。     

Tile‐based polygon overlay of vector data in a virtual globe

The demand for analysis of large‐scale data has increased with increased access to spatial vector data. Polygon overlay of vector data in a virtual globe requires proprietary data structures and proprietary analysis algorithms. A vector data structure is designed for rapid polygon overlay in a virtual globe by recording the metadata of the triangles (TriMeta) that constitute polygons. A polygon overlay algorithm is proposed based on this data structure. The overlay of two complex GIS polygons is transformed into the intersection computation of their 3D triangular presentations. The intersection computation of two sets of triangles is reduced considerably by utilizing TriMeta to filter out the disjoint triangle pairs and rapidly identify the contained triangle. The new method improves the overlay efficiency in a virtual globe because the amount of computation required to calculate the intersections of two large polygons and drape the intersections onto a terrain surface is reduced.     

Spatial optimization of rural settlement relocation by incorporating inter‐village social connections under future policy scenarios

Social connections between villages can represent farmers’ interests and thus benefit participatory rural relocation planning. With rural development, however, these connections will change and may weaken the adaptation of relocation plans to future rural systems. As yet, most studies still use empirical social connections to guide relocation planning, while a few have incorporated predicted connections in the context of rural development into relocation decisions. Meanwhile, spatial optimization approaches have seldom been adopted to solve this geographical decision issue. Accordingly, our study proposes a novel spatial relocation framework that incorporates changed inter‐village social connections under future rural development scenarios. Empirical inter‐village connections and their policy‐induced changes in central China were explored using social network analysis. An integration of particle swarm optimization and geographic information systems was adopted to identify the relocation solutions with maximum inter‐village connections and maximum spatial land use compactness, and to examine how connection changes under different policy scenarios influenced relocation outcomes. The results demonstrate the significance of incorporating policy‐induced social connections into relocation plans, and most importantly, show the negative relations between changed social connections and the migration distance/direction of relocated settlements. Our study is expected to improve the adaptation of relocation plans to future rural development.     

定位参数抗差估计的无偏性

根据抗差估计中误差的最基本假设—对称分布 ,考虑到ρ函数的条件及把反对称估计作为抗差估计计算迭代的初始值 ,验证了定位参数的抗差估计值也一定是反对称估计 ,满足无偏性条件 ,得到定位参数的抗差估计是无偏估计。     

L_∞估计的方法研究

讨论了 L∞ 估计的基本原理 ,提出了利用线性规划来求解 L∞ 估计问题的方法 ,并且依据线性规划的对偶原理给出了求解问题的实用方法。