证据推理应用于多源信息融合分析

运用证据理论合并来自不同数据源的证据,以实现各种数据所含信息融合的原理和方法。该方法的最大特点是将数据源中存在的不确定性引入数据分析过程。另外,利用证据推理,可以在数据分析过程中方便地引入专家解译图解的经验和知识。最后通过利用ＥＲＳ ＳＡＲ数据和ＴＭ影像进行融合分析,证明该方法在遥感图解自动分类中有很好的应用前景。     

一种基于小波变换的新的边缘检测方法

阐述了基于小波变换模局部极大值的多尺度边缘检测原理.提出一种基于图像的小波分解细节来检测图像边缘的方法,经实验,该方法得到的边缘图像明显好于经典的边缘检测算子.     

证据理论结合遥感分类数据能力定量评价研究

DS(Dempster-Shafer)证据理论具有结合多源数据的能力,在遥感分类中应用越来越广泛.然而,并不是所有数据源利用证据理论结合后都能提高目标类别的基本概率分配(Basic Probability Assignment,BPA),从而提高遥感分类效果.如何对证据结合的效果进行评价已成为应用证据理论的一个关键问题...     

高拱坝多效应量改进型D-S证据理论融合模型

针对目前高拱坝监测资料分析中单效应量分析方法存在的不足,将数据融合技术中的D-S证据理论引入到高拱坝多效应量融合建模之中,提出了一种适合于高拱坝D-S证据融合评价的新的融合系数运算公式,建立了基于改进型证据理论的高拱坝多效应量融合模型。工程实例分析表明,该方法合理、可行,并可降低高拱坝安全评价中的不确定性与未知性。     

一种基于证据理论的多极化SAR图像分割方法

本文提出了一种基于证据理论的融合像素信息和上下文信息的多极化合成孔径雷达(SAR)图像分割方法.D-S证据理论是一种不确定性推理方法.基于D-S的SAR影像分割方法将像素信息和上下文信息看作两类证据,先对高度平滑后的影像作初始的过分割,然后基于D-S理论对初始分割图斑的边界进行迭代修正,最后再融合两类证据对初始分割的图...     

基于分形理论的SAR图像边缘检测

分析了ＳＡＲ图像的基本特点,阐述有ＤＦＢＲ模型表达ＳＡＲ图像的基本原理,提出两种基于分形理论的ＳＡＲ图象边缘检测方法。通过对传统方法、分形方法和多尺度分形方法的特性分析和实验,说明了分形方法有较强的抗干扰性能,适用于ＳＡＲ图象的边缘检测,并且基于多重分形的方法能获得更好的检测结果。     

数字图像边缘检测方法的探讨

首先介绍有关边缘的定义与特征,阐述边缘检测方法Roberts算子、Prewitt算子、Sobel算子、二次微分(Laplacian算子)、模板操作(Kirsch模板、Prewitt模板),并介绍Marr理论的边缘检测方法。还简单说明边缘检测的应用。     

基于数学形态学细化算子的改进Canny算法研究

边缘检测是图像处理领域研究的一个重要内容。本文基于数学形态学改进现有Canny算子。该方法首先用Canny算子进行滤波,然后采用非极大抑制技术,将强边缘图像和弱边缘图像的边缘进行连接,再对提取的边缘利用形态学细化算子细化。针对不同图像采用不同门限比例,可取得不同的边缘提取效果。本文采用峰值信噪比、均方误差、平均绝对误差三个评价指标对边缘检测算法的优越性进行度量。实验分析表明,本文算法优于Sobel算子、Roberts算子、Log算子及传统Canny算法。     

基于D-S理论的多源空间位置信息不确定表达及融合模型研究

首先对空间信息不确定性进行了定义,并应用证据理论框架对空间信息的表达进行分析及建模;然后在合理假设的基础上,进行数学推理,得出不确定性边界函数的求解模型和实现方法;最后构建多源位置信息融合模型,实现一定置信度下的空间位置信息范围的确定,并通过实例分析和验证该模型的可行性和有效性。     

基于边界特性改进直方图门限法的道路提取

针对经典边缘检测算子在提取道路边缘时，易于受到房屋边界、地类界等线性目标的干扰，使得检测出道路边缘的同时混有其它非道路线现象，提出一种基于边界特性改进直方图门限算法提取道路边缘像素，利用边缘像素改善直方图检测道路像素的方法。该算法首先获取道路边缘像素，然后通过形态学运算得到初始道路段，细化获取道路中心线，最后对其进行判断编组连接得到道路网络。     

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。