基于语义规则的高分辨率影像道路交叉口提取方法

为了准确提取遥感影像上道路交叉口目标,提出一种利用特征语义规则从高分辨率影像上提取道路交叉口的方法。该算法构建交叉口模型时将其视为由同质区域像素集合及区域轮廓边界构成的面对象,提取过程分为两步:1)利用辐射、纹理特征语义匹配提取交叉口候选区域;2)通过几何特征语义匹配筛选候选区域、识别交叉口属性。利用多源遥感影像对算法正确性及合理性进行验证,结果表明:算法能准确、完整地提取道路交叉口,可为影像道路网构建提供辅助信息。     

无人机遥感影像匹配中的优化SIFT-OCT算法

针对传统尺度不变特征转换(SIFT)算法在高分辨率影像中检测特征点数量多、匹配效率低、无法快速对无人机低空遥感影像进行特征匹配的问题,该文优化SIFT-OCT算法的特征检测、特征匹配方法,主动放弃第一组尺度空间进行特征检测,并采用影像分块的方法加快检测过程;在特征匹配阶段,提出相似性系数进行匹配点对二次筛选,利用随机抽样一致性(RANSAC)算法计算透视变换模型参数进行精匹配.选取同一无人机序列影像中的4组不同地物类型的影像进行对比验证实验,结果表明,优化SIFT-OCT算法极大地限制特征提取数量,提高影像匹配效率,适合无人机低空遥感影像匹配.     

基于邻域投票和Harris-SIFT特征的低空遥感影像匹配

文中提出一种基于邻域投票和改进的Harris-SIFT特征的低空遥感影像匹配方法。首先用NMS算法提取多尺度的Harris-SIFT特征并对其进行方向描述,然后根据最近邻与次近邻特征点距离之比确定初始匹配点对,最后通过近邻域选择投票的方法剔除候选点中的虚假匹配点,进而实现低空遥感影像的配准。实验表明该算法在获得充足匹配点且保证匹配精度的同时,明显提高影像匹配的效率。     

一种喀斯特地貌无人机遥感影像的快速匹配方法

针对喀斯特地貌地形起伏大、沟壑纵深、影像局部存在阴影,该地区无人机遥感影像匹配难度大,该文提出一种基于AKAZE特征和RANSAC算法的喀斯特地貌无人机遥感影像的快速匹配方法。该方法采用AKAZE特征检测算法提取喀斯特地貌无人机遥感影像的特征点,能够较为精简地描述出影像的特征,影像匹配时间缩短,匹配速度提高明显;由于预匹配存在错误点对,利用单应性矩阵的RANSAC算法进行精准匹配,剔除错误匹配点对,同时得到最优的单应性矩阵。实验结果表明,该方法的匹配耗时和匹配正确率较优于经典的SURF和BRISK算法,该匹配方法更适合于喀斯特地貌无人机遥感影像匹配。     

基于点特征的低空遥感影像多级高效率匹配方法研究

研究基于点特征的匹配算法,结合现有影像匹配算子的优缺点,提出一种适用于低空遥感影像特征点的自动提取与匹配方法。首先在简化的高斯尺度空间中检测Harris角点,使该特征点具有尺度不变性;然后采用Forstner算子对关键点精确定位,精度达到子像素级;最后通过简化特征点描述符实现算法简化。在特征点匹配阶段,采用BBF-KD初匹配和二次精匹配提高匹配精度。以低空遥感影像为实验数据测评SIFT算法和文中方法在提取速度、匹配正确率、稳定性等方面的性能。实验结果表明,相对于传统的SIFT算法,处理影像清晰的低空遥感数据时本方法有更高精度和更快速度。     

形位相似的影像分割质量评价方法

针对传统遥感影像分割质量评价方法缺少定量评价,该文在顾及参考对象与分割对象之间形状和位置关系差异的基础上,提出一种基于形位相似的遥感影像分割质量评价方法。采用该文提出的评价方法对多尺度分割算法和分水岭分割算法的分割结果进行评价。结果表明:该方法能客观定量评价分割影像质量,得到最佳影像分割结果对象与参考对象的边界具有较高形位相似;并且该文评价方法能确定遥感影像最佳的分割尺度参数,有利于提高后续基于面向对象分类方法的精度。     

多光谱遥感影像亮度空间相位一致性特征点检测

提出了一种基于亮度空间和相位一致性理论的多光谱遥感影像特征点检测算法。首先利用参数自适应的灰度变换函数建立影像亮度空间;然后结合相位一致性方法在影像亮度空间进行候选特征点检测,并将候选特征点映射到原始影像上进行非极大值抑制;最后在尺度空间计算特征点的特征尺度值。本文方法有效结合了亮度空间特征检测和相位一致性特征检测的优势,对多光谱遥感影像的辐射变化具有较强的稳健性。试验结果证明,与传统特征点检测算法相比,本文方法在特征重复率和重复特征数量方面都具有明显的优势。     

基于MBR组合优化算法的多尺度面实体匹配方法

针对多尺度匹配中同名实体位置偏差较大,无法直接通过面积重叠法获得候选匹配的问题,本文提出了一种基于最小外包矩形（MBR）组合优化算法的多尺度面实体匹配方法。本文方法的基本思想是通过MBR组合优化和简要的形状特征来筛选1∶1、1∶N和M∶N候选匹配,然后构建多因子人工神经网络模型来评估候选匹配。试验选取浙江省舟山市1∶2000岛礁基础数据和1∶10 000陆地基础数据中的居民地与设施面进行匹配算法的验证。结果表明,本文方法相对于基于面积重叠-神经网络的匹配方法表现出显著的优势,对存在位置偏移的匹配数据准确率和召回率分别达到了达到96.5%,达到89.0%,且能够识别所有匹配类型。     

基于多尺度形变特征卷积网络的高分辨率遥感影像目标检测

传统的基于滑窗搜索和人工设计特征相结合的目标检测方法难以适用于海量高分辨率遥感图像的目标检测任务。本文提出了一种基于多尺度形变特征卷积网络的目标检测方法,利用可形变卷积网络对具有尺度和方向变化的遥感图像目标进行特征提取,然后对多层残差模块提取出的形变特征进行区域预测和鉴别。具体模型包括两个子网络：①目标区域预测子网络用于从多层深度特征图提取目标候选区域;②目标区域鉴别子网络用于对目标候选区域进行分类和位置回归。本文在光学卫星图像10类目标数据集上对比了多种基于深度学习的目标检测算法,并将训练好的模型用于谷歌地球影像飞机坟场数据集和高分2号、吉林1号数据集的评估,试验结果表明本文方法能够快速准确地对多类目标进行检测,具有较好的稳健性和迁移性。     

利用特征组合检测算法的无人机遥感影像匹配研究

影像匹配是无人机遥感影像拼接和三维建模的基础和关键步骤。结合不同算法的优势,本文提出一种基于特征组合与RANSAC算法的无人机遥感影像匹配方法。该匹配方法首先采用AKAZE算法检测影像的特征点,然后利用SIFT描述符描述特征向量并获取特征点的主方向,最后基于单映射变换矩阵的RANSAC算法进行精准匹配。本文对基于特征组合与RANSAC算法的匹配效果进行了试验对比分析,试验结果表明：与常用匹配方法的匹配效果相比,本文的匹配方法继承了AKAZE算法的快速匹配能力,匹配总耗时介于AKAZE算法和SIFT算法之间,约为BRISK算法匹配耗时的20%;同时,该匹配方法继承了SIFT算法的多匹配点对性能,从整体匹配效果来看,本文的匹配方法优于AKAZE、SIFT、BRISK算法。     

阿克苏河-塔里木河水系水质污染遥感监测与评价

 采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的 污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体 污染变化曲线,得出污染物浓度随着远离上游而增加。     

Monitoring drought dynamics in the Aravalli region (India) using different indices based on ground and remote sensing data

The hard-rock hilly Aravalli terrain of Rajasthan province of India suffers with frequent drought due to poor and delayed monsoon, abnormally high summer-temperature and insufficient water resources. In the present study, detailed analysis of meteorological and hydrological data of the Aravalli region has been carried out for the years 1984–2003. Standardised Precipitation Index (SPI) has been used to quantify the precipitation deficit. Standardised Water-Level Index (SWI) has been developed to assess ground-water recharge-deficit. Vegetative drought indices like Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) and Vegetation Health Index (VHI) have been computed using NDVI values obtained from Global Vegetation Index (GVI) and thermal channel data of NOAA AVHRR satellite. Detailed analyses of spatial and temporal drought dynamics during monsoon and non-monsoon seasons have been carried out through drought index maps generated in Geographic Information Systems (GIS) environment. Analysis and interpretation of these maps reveal that negative SPI anomalies not always correspond to drought. In the Aravalli region, aquifer-stress shifts its position time to time, and in certain pockets it is more frequent. In comparison to hydrological stress, vegetative stress in the Aravalli region is found to be slower to begin but quicker to withdraw.     

Landslide risk analysis between Giri and Tons Rivers in Himachal Himalaya (India)

The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies.     

Gravity Changes Before Large Earthquakes in China: 1998-2005

Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200...     

GNSS系统及其技术的发展研究

阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议.     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Virtual Australia: its key elements – know,think, communicate

Abstract

Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised.     

Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services

Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.     

GIS空间数据的采集误差及其分析

本文详细阐述了GIS数据采集过程中的误差来源，重点分析了通过地图、遥感和摄影测量等方式采集数据所产生的误差及其特性，分析了其对GIS数据的影响与消减方法。     

地理数据库的关系模型及其实现

本文从以图论观点分析地理实体入手,系统阐述了地理数据库关系模型的设计法和过程。作者于1984年4～9月间在微型机上设计建立了关系型地理数据库的实方验系统(RGDB)。该系统采用了本文提出的关系模型,采用了可动态扩库的子库组合结构,这种结构具有灵活性和提高空间利用率的优点。RGDB含有多种功能的数据操作命令,除了具有一般检索功能外,还能进行“开窗”选取和十分“自由”的映象选取。本文对RGDB系统的主要性能和实现途径作了扼要介绍。