改进的矩匹配遥感影像条带噪声去除方法研究与实现

遥感传感器在扫描成像过程中,由于感光单元间的响应差异和其他因素,有时会产生条带噪声,这严重影响了影像的应用。为了更好地利用这些影像,必须首先对影像进行去条带处理。首先对比分析两种基于同一个传感器单元获取的影像具有统计一致性假设的条带噪声去除算法,即均值归一化方法和矩匹配方法,再对矩匹配方法进行了改进,并在VC++6.0下分别编程实现。经过对有条带噪声的IRS5.8 m分辨率全色遥感影像进行处理和对比分析,在光谱保持和条带噪声去除效果综合考虑下,得出改进的矩匹配方法优于均值归一化方法。     

资源一号02C影像条带噪声去除的改进矩匹配方法

针对资源一号02C 影像条带噪声的去除,提出了一种改进的矩匹配方法。该方法以移动窗口的方式对大范围卫星影像数据进行分段处理,并根据窗口内影像的信息量,自适应地确定窗口大小,且在参考值获取时引入更合理的高斯加权均值。实验表明,与现有矩匹配方法相比,本文方法在取得良好去噪效果的同时,还具有自动化程度高、灰度失真小等优点。     

双边滤波与矩匹配融合的高光谱影像条带噪声去除方法

针对环境减灾小卫星高光谱影像数据中存在的条带噪声,提出一种双边滤波与矩匹配方法融合的去除条带噪声方法。该方法克服了传统方法在去除条带噪声的同时带来新的噪声,并且边缘信息丢失等问题。最后进行了几种去除条带方法的比较试验,并且对试验结果进行了讨论。试验证明,提出的方法去除高光谱遥感影像的条带噪声效果明显,且能较好地保留原始影像中的地物信息。     

成像光谱仪图像条带噪声去除的改进矩匹配方法

条带噪声是影响线阵CCD成像质量的一个重要因子。特别是对于CCD质量要求较高的高光谱成像往，往往由于硬件质量造成了许多通道中条带噪声的出现。分析了条带噪声形成的主要原因，比较了几种常用条带噪声去除方法及其局限性。在此基础上指出，标准的矩匹配方法改变了图像在成像行或列方向的均值分布，造成了一定的灰度畸变。这种情况对于在地物非均匀分布状况下成像的小幅图像尤其明显。着重提出和讨论了利用均值补偿法，傅里叶变换法，相关系数法结合矩匹配方法近似恢复由入射辐射强度产生的均值分布，从而达到保持图像质量并有效去除条带噪声的目的。并对条带噪声去除前后图像质量做了定性定量的比较，评价。     

频域滤波与直方图匹配相结合的条带噪声去除法

针对高分辨率遥感影像中存在的条带噪声,提出了一种频域滤波与直方图匹配相结合的去噪方法。首先利用变换域的方法提取条带噪声;再利用butterworth滤波器滤除条带噪声成分;最后将滤波后的结果影像作为参考影像,对原始含条带噪声的影像进行基于影像列的直方图匹配。实验结果表明,该方法能有效去除条带噪声。     

一种改进的Hu不变矩多源影像匹配方法

Hu不变矩对多源影像进行匹配时,无法对抗大幅度旋转和灰度差异,而且计算量较大无法快速匹配。本文结合多源影像之间的区别和联系,针对Hu不变矩的适用性和计算过程,从匹配窗口设计、影像预处理、亮度因子、计算过程等4个方面进行改进。实验结果表明,改进后的Hu不变矩匹配方法可以抵抗大幅度影像旋转和灰度差异,而且提高了匹配准确度和速度。     

基于改进矩匹配算法的珠海一号高光谱卫星影像相对辐射校正

珠海一号高光谱卫星影像部分波段存在着噪声干扰,严重影响了数据的质量与信息利用.本文分析了珠海一号高光谱卫星数据噪声的特点,在矩匹配算法的基础上,使用移动窗格对影像进行分段处理,并采用距离加权计算与去除极端值统计数据的方法提高参考值的准确度,实现了基于影像的相对辐射校正.实验结果表明,与传统矩匹配法和傅里叶滤波法相比,本文方法能有效去除遥感影像中存在的噪声,并能较好保留原影像的辐射特征.     

Terra MODIS数据28波段影像条带噪声去除方法

Terra卫星MODIS传感器影像中多个波段数据存在条带噪声,其中第28波段的数据受影响较为严重,且随着时间的推移噪声强度更大、噪声类型更加复杂。针对该波段同时受探元-探元噪声与镜面条带噪声影响的特点,本文在矩匹配方法的基础上,提出了基于曲线拟合与去除信号趋势项的条带噪声去除方法。实验结果表明,相对于传统方法,本文提出的两种条带去除方法具有更强的稳健性。     

基于影像尺度空间表达与鲁棒Hausdorff距离的快速角点特征匹配方法

快速影像匹配是进行影像时间序列分析与飞行器导航的重要方法.本文对待匹配影像进行高斯低通滤波预处理时,运用影像的尺度空间表达思想对不同分辨率的基准影像和实时影像选择了相应的σ值进行卷积滤波处理,使基准影像和实时影像具有相近的分辨率,从而提高两影像所提取角点的重复率,使得影像的正确匹配概率得到提高.然后用基于影像几何结构分析的改进的快速角点探测算法进行了影像的角点提取;最后用本文提出的改进的鲁棒Hausdorff距离进行了基准影像和实时影像的匹配.实验证明,本文方法对影像噪声和灰度变化不敏感,具有抗影像尺度变化的能力.在基准影像和实时影像灰度差变化较大的情况下,依然能取得较高的正确匹配概率.由于采用基于影像信息量评价的搜索策略和快速角点提取算法,匹配速度也较快.     

基于不变矩的影像匹配搜索算法

矩在统计学中用于表征随机量的分布，直方图不变矩反映了图像灰度分布的统计特征。本文在对不变矩进行深入探讨的基础上，提出了基于圆表搜索模板的图像直方图不变矩搜索方法，并对两幅待融合影像进行了较高精度的灰度搜索匹配试验，取得了较好的结果。     

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。