SPOT5影像目视判读在土地利用类型更新中的应用研究

近年来,SPOT 5影像被广泛应用于土地利用类型的调查中[1],一方面,为我们进行土地利用类型分类更新提供了新的信息源;另一方面,对遥感的室内解译提供了更高更新的要求.本文以常德市汉寿县为例探讨在进行土地利用类型分类更新中前期图像处理、解译标志的建立以及人工目视判读中的难点和重点,对于在遥感图上不易判读或容易判错的地物特征给予总结,一定程度上提高了遥感目视解译的准确性.     

深度细粒度图像识别研究综述

细粒度图像分类是计算机视觉中一项基础且重要的工作,其目的在于区分难以辨别的对象类别（例如不同子类的鸟类、花或动物）.不同于传统的图像分类任务可以雇佣大量普通人标注,细粒度数据集通常需要专家级知识进行标注.除了视觉分类中常见的姿态、光照和视角变化因素之外,细粒度数据集具有更大的类间相似性和类内差异性,因此要求模型能够捕捉到细微的类间差异信息和类内公有信息.除此之外,不同类别的样本存在不同程度的获取难度,因此细粒度数据集通常在数据分布中表现出长尾的特性.综上所述,细粒度数据分布具有小型、非均匀和不易察觉的类间差异等特点,对强大的深度学习算法也提出了巨大的挑战.本文首先介绍了细粒度图像分类任务的特点与挑战,随后以局部特征与全局特征两个主要视角整理了目前的主流工作,并讨论了它们的优缺点.最后在常用数据集上比较了相关工作的性能表现,并进行了总结与展望.     

Speckle observations with PISCO in Merate (Italy): XIV. Astrometric measurements of visual binaries in 2013 and new orbits for ADS 1097, 5871, 7203, 7775, 9378, 9578, and 11186

We present relative astrometric measurements of visual binaries made in 2013 with the speckle camera PISCO at the 102‐cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained 134 new measurements of 129 visual binary stars, with angular separations in the range 0.≈23–5 and an average accuracy of 0.≈01. The mean error on the position angles is 0.°5. Most of the position angles were determined without the usual 180° ambiguity with the application of triple‐correlation techniques and/or by inspection of the long integration files. We also present new revised orbits for ADS 1097, 5871, 7203, 7775, 9378, 9578, and 11186, partly derived from PISCO observations. The corresponding estimated values for the masses of those systems are compatible with the spectral types. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Micrometric measures and orbits of southern visual double stars

525 measures of 213 visual double stars have been made using the 26.5‐inch (67‐cm) Innes telescope in Johannesburg and the Repsold micrometer between 2008.375 and 2008.419, 2010.608 and 2010.652, and 2013.663 and 2013.712. A comparison with known orbits is made. Revised orbits are presented for WDS 01061–4643 (SLR 1), WDS 12415–4858 (HJ 4539), WDS 16253–4909 (COO 197) and WDS 16425–3705 (R 283). (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

附约束条件的零件轮廓线的多特征提取

在常用的多特征提取方法的基础上提出一种附加约束条件的零件轮廓线的多特征提取方法,即在已有方法提取的多特征结果上附加轮廓上圆弧与直线相切、相邻圆弧与圆弧相切等约束条件,对轮廓上的特征进行迭代精确提取,将组成轮廓的各特征如直线、圆弧和圆,进行精确分段识别,获得各特征的参数。最后使用模拟图像和实际的工业零件图像分别进行了试验验证,结果证明约束关系的引入能够有效地提高轮廓线多特征提取的精确度。     

多传感器影像配准中基于虚拟匹配窗口的SIFT算法

提出了一种基于虚拟匹配窗口的SIFT算法,通过构建虚拟匹配窗口,增大SIFT特征点之间的尺度相似性,提高了匹配的几率;并通过与最小二乘法和双线性内插法的结合完成自动配准。文中选取角度和尺度偏差较大的SPOT-5(P)与TM影像进行实验,结果表明,配准精度小于一个像素。     

带分类值排列算法的改进的Parallel Sets

针对分类型可视化工具Parallel Sets任意排列分类值产生较多交叉的不足,提出了基于中位数的启发式分类值排列算法,自动优化分类值布局顺序,减轻视图中的可视混乱,而后应用改进的Parallel Sets分析了全球恐怖主义数据库。实验结果表明,改进的Parallel Sets可清晰展现国际恐怖主义数据库中各分类值间的关联,从而辅助用户获取不同恐怖组织的行为特征等隐性信息;基于中位数的启发式分类值排列算法简单高效,适用于数据量较大、分类值较多的数据集。     

基于全球虚拟地形环境的空间分析方法研究

本文在介绍构建全球虚拟地形环境的基础上,着重研究了对全球虚拟地形环境进行交互操作和空间分析的方法;对空间分析中的基本量算功能、缓冲区分析和可视分析进行重点阐述,最后通过可视化的表现形式对各种分析状态进行空间表达.     

GeoScope: Full 3D geospatial information system case study

Aiming at the integrative management and comprehensive applications of large-scale 3D geospatial information covering the full 3D space of a city,this paper briefly introduces the design and implementation of a full 3D GIS platform:GeoScope,which provides a professional solution for the massive full three-dimensional geospatial data integration,management,analysis,visualization,and applications.GeoScope is characterized by:(1) extendible software architecture based on the hierarchical message bus,facilitates multimodal integrative applications of 2D GIS and 3D GIS;(2) unified 3D city models,support multiscale semantic representation of outdoor & indoor and aboveground & underground 3D objects;(3) high-efficient 3D geospatial database engine,supports integrated management of massive 3D geospatial data for real-time applications;and (4) high-performance visualization engine exploiting the massively parallel computation architecture of modern GPUs,supports real-time realistic rendering of large-scale complicated 3D geospatial environments.The successful pilot application of GeoScope is also illustrated with the 3D city models of 8494 km2 of the whole Wuhan City,the largest city in middle China.     

中国淅川虎睛石矿物特征及开发利用前景

中国淅川虎睛石是木变石的一种,但在颜色、幻彩效果、矿物结构等特征上和国外多个矿床的虎睛石有较大区别,其幻彩效果要优于国外木变石。从市场的角度可将淅川虎睛石质量分为宝石级、工艺级、观赏石级和普通级。淅川虎睛石加工利用率高,市场情况良好,开发价值高,前景良好。