Evaluating Local Non-Stationarity when Considering the Spatial Variation of Large-scale Autocorrelation

Multi‐scale effects of spatial autocorrelation may be present in datasets. Given the importance of detecting local non‐stationarity in many theoretical as well as applied studies, it is necessary to “remove” the impact of large‐scale autocorrelation before common techniques for local pattern analysis are applied. It is proposed in this paper to employ the regionalized range to define spatially varying sub‐regions within which the impact of large‐scale autocorrelation is minimized and the local patterns can be investigated. A case study is conducted on crime data to detect crime hot spots and cold spots in San Antonio, Texas. The results confirm the necessity of treating the non‐stationarity of large‐scale spatial autocorrelation prior to any action aiming at detecting local autocorrelation.     

Small target extraction based on independent component analysis for hyperspectral imagery

IntroductionFeature extraction or transformation is a key stepfor target detection in hyperspectral imagery. Thepurpose is to transform the high-dimensional imageinto low-dimensional image series so that the differ-ences between the targets and the backgr…     

雷达遥感六十年：四个阶段的发展

雷达遥感问世60年来已经历了4个阶段的发展,其在对地观测中的作用正日益凸显,已经广泛应用于不同领域。4个阶段分别是单波段单极化阶段,多波段多极化阶段,极化和干涉阶段,以及以双/多站或星座、高时序高分宽幅、3维成像为代表的新阶段。本文结合作者长期在雷达遥感领域的研究经历,总结和回顾了雷达遥感的阶段发展和具有里程碑式的代表性技术;从观测技术、数据处理和应用角度阐述了新阶段雷达遥感的发展趋势,以及雷达遥感与人工智能和大数据结合的思考;最后着眼未来,介绍了月基雷达对地观测平台的前瞻性研究。     

The Landscape of GIScience Publications 1997–2007: An Empirical Investigation with Latent Semantic Analysis

This article reports on an empirical study of the trends and patterns of research activities in Geographic Information Science (GIScience) during the years 1997–2007. The GIScience research priorities identified by the University Consortium of Geographic Information Science (UCGIS) were used as guidelines to examine the 985 research articles published in six well‐recognized academic journals. Latent Semantic Analysis (LSA) was employed to investigate the association among the different GIScience research themes. The spatial and temporal patterns of the association between the publications and the different GIScience themes were examined to show the development of GIScience research during the study period. Furthermore, correlation analyses between the publications were conducted following the LSA results to reveal GIScience research networks, including the networks of the published articles and those formed by the research places. In this article, we applied an approach that was developed within information science to depict what GIS research activities were conducted when and where and how they connect to each other through sharing common research themes. The related findings pave the way for future efforts to describe the paradigm of GIScience as well as the pattern of GIScience research.     

一种顾及相干性的星载干涉SAR成像算法

在分析相干性与多普勒中心频率差之间关系的基础上,提出了一种顾及相干性的星载干涉SAR成像算法。在成像处理中,针对待干涉成像的SAR回波信号选择一致化的成像参数,充分保证干涉SAR复数影像对之间的相干性,进而得到高质量的干涉图。实验结果表明,所提出的成像算法更适用于雷达干涉测量(InSAR)的研究及应用。     

利用多源遥感数据进行城市不透水面覆盖度估算

利用深圳实验区4种不同传感器获取的遥感数据,通过CART算法进行城市ISP估算。讨论了多光谱遥感数据的不同波段在ISP估算中的重要性,比较了针对三种不同中分辨率影像建立的ISP估算模型在性能上的差异。实验结果表明,近红外波段对ISP估算结果的贡献最大,具有较高空间分辨率和成像辐射质量的遥感影像得到的估算结果精度较高,所有的估算结果均在实际ISP分布范围的两端分别存在着高估和低估的现象。     

玉米作物极化SAR数据模拟

通过重点研究玉米叶子的空间位置、指向角分布,分析玉米作物的结构特点,建立玉米的三维结构模型和场景,发展针对玉米作物的极化合成孔径雷达(synthetic apertureradar,SAR)数据模拟方法。利用该模拟方法和实地获取的玉米参数模拟极化SAR数据,通过与散射计实地测量的多极化、多角度后向散射系数进行对比,表明该模拟方法能够有效的模拟玉米作物的后向散射系数;通过分析模拟极化SAR数据获得的HH-VV、HH-HV、VH-VV之间的相位差,表明该模拟方法能够有效的模拟玉米作物散射的相位信息;通过分析模拟数据的极化响应图和Cloude H-α分类图,从散射类型角度验证了模拟极化SAR数据的有效性。     

GPS在古镇溱潼的应用实例分析

结合古镇溱潼地籍测量工作的开展,就先期展开的一级GPS控制测量进行步骤说明,并就后续的数据解算进行分析。     

鲜水河断裂带的构造大地测量

利用短边GPS点阵、短基线标石阵和精密激光测距 ,在与鲜水河断裂带的断层破裂带垂直的剖面上和构造盆地内进行构造大地测量 ,获得了断层软弱带和断层蠕变带上的最佳形变分布。综合利用相关地学成果和理论 ,揭示了构造形变所隐含的动力学信息 ,识别了断层应变带、塑性流变带和主断面在地面的分布范围。用外围GPS远场联测成果探讨了该断裂带的驱动力机制 ,匡正了其“左旋”运动和现今活动速度的含义。最后 ,评估了该断裂的地震活动趋势     

1962—1986年JYD1968.0地极坐标的均匀化及其与BIH的比较

本文研究了１９６２－１９８６年ＪＹＤ１９６８．０地极坐标均匀中星表系统差，章动系列的变动和光行星常数变动的影响，并将经过改正后的ＪＹＤ１９６８．０地极坐标系统和ＢＩＨ系统作了比较。