不同分辨率遥感影像获取均匀分布匹配点的匹配方法研究

基于SIFT算法提出一种适合于不同分辨率遥感影像并能获取均匀分布匹配结果的匹配方法,该方法首先将匹配区域进行分块,然后针对每个分块区域提取SIFT影像特征,在提取过程中,通过不同层级高斯影像塔和高斯差分影像的分级实现匹配点数量的控制,从而获取均匀分布的匹配点对。     

一种基于格网索引优化的遥感影像自动配准算法

针对SIFT算法在遥感影像配准过程中捕获配准点对数量较少和误匹配较多等问题,提出了一种基于格网索引的遥感影像自动配准的算法。首先,采用SIFT算法提取特征点和特征向量,并通过欧氏距离进行匹配;其次,建立格网索引剔除部分误匹配点对,从而提高了随机抽样一致算法的精度;最后,使用多项式几何纠正算法实现遥感影像的精确配准。实验结果表明:该算法比传统分块算法在遥感影像中得到的匹配点对精度更高,并且考虑到不同遥感影像配准场景的差异。     

一种运用AKAZE特征的无人机遥感影像拼接方法

针对无人机遥感影像旋偏角大、地面覆盖范围小等特点,提出一种运用AKAZE特征匹配算法实现无人机遥感影像的快速拼接。该方法利用AKAZE算法提取影像特征点,采用比值法、RANSAC算法计算出拼接序列之间的单应矩阵,通过中心距离范数加权法进行融合。实验表明,其配准精度优于ORB算法,与SIFT算法相当,而运算效率高于SIFT算法,但不及ORB算法,是一种稳定高效的无人机影像拼接算法。     

带匹配支持度的多源遥感影像SIFT匹配方法

通过将匹配支持度的相似性测度引入SIFT特征匹配算法,提出了一种能够应用于不同源遥感影像的自动匹配方法。首先,建立待匹配影像中特征点的SIFT特征描述符;然后,以待匹配点与参考点间的欧氏距离为相似性测度,挑选一定数量的距离最为接近的匹配点作为候选点;最后,分别计算候选匹配点间的匹配支持度,并通过松弛法剔除误匹配点以完成影像的自动匹配。实验结果表明,与传统的灰度匹配及经典的SIFT特征匹配相比,此算法可明显提高影像匹配的成功率和可靠性。     

基于SIFT的宽基线立体影像最小二乘匹配方法

提出基于对极几何和单应映射双重约束的SIFT特征多尺度加权最小二乘匹配算法。算法首先基于特征点的空间分布和信息熵选取一定数量的最优SIFT特征点集,并采用基于奇异值分解(SVD)的SIFT特征匹配、基于SIFT特征尺度和方位信息的自适应归一化互相关(NCC)匹配获得精度较高的初始匹配点用于立体像对的基本矩阵和单应矩阵估计。然后在对极几何和单应映射的双重约束下,基于自适应NCC及距离加权的多尺度最小二乘匹配算法进行扩展匹配并同时保留匹配定位精度较高的原始SIFT特征点对。算法综合应用基于积分影像的NCC快速计算、金字塔影像匹配等方法和策略。最后选取实际的宽基线序列立体影像进行试验并同原始的SIFT特征匹配算法、基于SVD的SIFT算法进行了综合对比分析。结果表明当影像间无显著亮度变化时该方法的匹配性能明显优于现有的方法。     

基于SIFT特征匹配和射影变换的控制点快速量测方法研究

针对无人机影像控制点量测人工作业量大的问题,本文提出了一种基于SIFT特征匹配算法和射影变换关系的无人机影像控制点位置预测方法:首先对控制点影像和待量测影像进行匹配,然后利用同名像点坐标计算影像间单应矩阵,最后计算待量测影像上的控制点坐标,达到控制点位置预测的效果。基于VS2010平台开发控制点位置预测软件并进行测试。实验表明:该软件可用于无人机影像控制点位置预测,大大提高了控制点量测效率。     

一种改进的多源遥感影像SIFT算法匹配策略

传统SIFT算法在遥感影像中相似性场景大量存在的情况下呈现出匹配效率低的问题。文中提出对传统SIFT算法匹配策略进行改进,其步骤包括:首先在初匹配阶段,利用建立金字塔影像匹配的方式确定影像间的几何关系模型;其次,利用该几何关系模型对初始影像进行约束匹配;最后利用RANSAC模型剔除误匹配点。通过相似性场景影像匹配实验可以表明,与传统SIFT算法相比,本方法具有明显的匹配效率和精度优势。     

一种适合航空影像的直线匹配方法

针对航空影像中高程变化对视差影响较大,而传统的单应矩阵与几何约束未考虑视差影响的问题,该文提出了一种适合航空影像的直线匹配方法。首先采用尺度不变特征变换(SIFT)算法进行特征匹配,并计算立体影像间的基础矩阵,通过核线纠正消除其上下视差;然后计算影像间的单应矩阵,并对Hough变换提取的直线段进行变换,最终通过直线段间的端点距离作为约束条件实现了直线匹配。采用多组航空影像开展了实验,结果表明:针对航空影像中高程变化较大的区域,提出的方法可以减少视差的影响,匹配效果优于传统单应矩阵与几何约束的方法,且匹配可靠性高。     

遥感影像在最大极值范围的并行稳定匹配

针对目前立体影像匹配时普遍存在的配准稳定性与配准精度不能同时兼顾问题,该文采用金字塔和分块策略,首先在多尺度空间下进行粗匹配,获得大量的初始特征点集;然后通过限制金字塔影像的阶数对初始特征点进行坏点剔除和滤点均匀化来获得良好的初始特征点;最后通过进行分块影像并行化SIFT算法匹配来实现精确匹配,提高效率.实验结果证明,此遥感立体影像并行稳定匹配方法能够提高匹配的效率,对影像的旋转、缩放和视角变换具有更强的抵抗性,其配准精度较高,适用于大范围的遥感立体影像的匹配.     

遥感影像在最大极值范围的并行稳定匹配（英文）

针对目前立体影像匹配时普遍存在的配准稳定性与配准精度不能同时兼顾问题,该文采用金字塔和分块策略,首先在多尺度空间下进行粗匹配,获得大量的初始特征点集;然后通过限制金字塔影像的阶数对初始特征点进行坏点剔除和滤点均匀化来获得良好的初始特征点;最后通过进行分块影像并行化SIFT算法匹配来实现精确匹配,提高效率。实验结果证明,此遥感立体影像并行稳定匹配方法能够提高匹配的效率,对影像的旋转、缩放和视角变换具有更强的抵抗性,其配准精度较高,适用于大范围的遥感立体影像的匹配。     

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。