Using Spatial Analysis to Understand the Spatial Heterogeneity of Disability Employment in China

During the formulation of employment disability policy, policymakers are often interested in regional variations of disability employment. Decision‐makers are required to distinguish between various geographical factors. However, few previous studies take spatial heterogeneity into account and most of them conducted only a qualitative analysis. Geographical detectors based on spatial variation analyses of identified factors were applied in the study to establish connections between regional features and the disability employment rate, and to identify the city groups with significantly higher and lower percentage rates of disability employment. It is the first application of spatial statistics in studying the employment problem of the disabled. The findings can help the government formulate reasonable adjustments to both job opportunities for, and work roles of, disabled people.     

A piecewise based high-precision registration of InSAR data

In Synthetic Aperture Radar (SAR) interferometry, the precise co-registration is a key problem to obtain the fine interferogram. Theoretically, 1/10 pixel accuracy is essential. Once the control points are determined, the relative rectification (pixel re-sampling)is also the important procedure. In this paper,a piecewise transformation algorithm based on Delaunay Tessellation algorithm is developed. The strategy is to "anchor" geographically all control points and transform the imagery on the basis of triangle by triangle. The piecewise algorithm, the accuracy evaluation and the preliminary results are described. The experiment result shows that the piecewise transformation out-performes the traditional polynomial transformation.     

地极坐标系统及其相互关系

本文回顾了各种地极坐标系统的状况，包括地极坐标原点的定义、系统的组成和这些系统之间的相互关系等。地极坐标系的原点，就是地球参考系Ｚ轴与地面的交点，因而选择某个地极坐标原点，在实际上也选取了相应的地球参考系。本文还详细叙述了常用的各种地球参考系原点和轴向的定义，实现的方法、精度，不同地球参考系之间的转换参数等等。     

数字表面模型的建筑物容积率提取

针对阴影长度和阴影面积法计算建筑物容积率误差较大的情况,该文利用航空影像密集匹配生成的点云数据逐点内插生成数字表面模型,提取建筑物三维信息,同时对于复杂建筑物屋顶,利用坡度滤波将其分割成为高度不同的面片,计算每一块屋顶的层数,从而得到较为准确的建筑总面积。实验证明,利用本文方法得到的建筑物容积率准确率高,且具有较高鲁棒性和使用价值。     

卫星云图处理系统

本文介绍了以微型计算机(IBM-PC)为基础的同步气象卫星云图处理系统,论述了数据采集、分层显示、投影变换以及边缘勾划等功能的实现,並提出若干特殊处理的方法。     

Iteration convergence condition modeling for single spaceborne SAR image direct positioning

Single SAR image direct positioning is to determine the ground coordinate for each pixel in the SAR image assisted with a reference DEM. During this procedure, an iterative procedure is essentially needed to solve the uncertainty in elevation of each pixel in the SAR image. However, such an iterative procedure may suffer from the problem of divergence in shaded and serious layover areas. To investigate this problem, we performed a theoretical analysis on the convergence conditions that has not been intensively studied till now. The Range-Doppler (RD) model was simplified and then the general surface is degenerated into a planar surface. Mathematical deduction was then carried out to derive the convergence conditions and the impact factors for the convergence speed were evaluated. The theoretical findings were validated by experiments for both simulated and real scenarios.     

Absolute geolocation accuracy of high-resolution spotlight TerraSAR-X imagery – validation in Wuhan

TerraSAR-X (TSX) can acquire high-resolution SAR images and due to its high orbit precision as well as its ability to acquire data from different off-nadir viewing angles, the high-precision stereo geolocation can be obtained. In this study, we investigate the absolute geolocation accuracy of TSX high-resolution images in Wuhan, China. We present a direct stereo SAR geolocation method and analyze the 2D and 3D geoposition accuracy of two corner reflectors. The sub-meter localization accuracy was achieved using only atmospheric correction information available in the TSX metadata.     

Interactive generalization on large-scale topographical map supported by a database platform

This paper makes a study on the interactive digital generalization, where map generalization can be divided into intellective reasoning procedure and operational procedure, which are done by human and computer, respectively. And an interactive map generalization environment for large scale topographic map is then designed and realized. This research focuses on: ¹ the significance of researching an interactive map generalization environment, ² the features of large scale topographic map and interactive map generalization, ³ the construction of map generalization-oriented database platform.     

一种新的布设沉降观测点的方法

一些构筑物,不能按常规方法埋设观测点,介绍一种新的布设沉降观测点的方法一粘合观测点法,并通过工程实践,对新观测点稳固性进行了统计、分析。     

青海软玉与新疆软玉的对比研究

通过青海软玉与新疆软玉较系统的比较研究，总结出青海软玉与新疆软玉的异同点，为青海软玉的市场定位提出意见和建议，并为软玉矿床的找矿与勘探指明了方向。