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1.
遥感图像中地表水体同山体、建筑物等地物产生的阴影在光谱特征上存在较高的类间相似性,导致提取过程中容易出现混淆和错分的情况。针对此问题,提出一种基于面向对象和人工蜂群的地表水体提取方法。该方法首先对遥感图像进行分割以获取分割对象的光谱、比率、几何形状等统计特征,以弥补高分遥感图像波段数目少,信息量不足的缺陷;并借助人工蜂群算法在解决复杂问题最优化方面的优势,选取水体同阴影二值分类的几何平均正确率作为算法的适应度函数,最终获取地表水体的最优化提取规则。选取厦门市大嶝岛和湖南省资兴市部分区域,基于国产高分一号、二号遥感数据进行水体提取,并与传统SVM分类结果进行比较。实验结果表明本算法提取水体的总体精度和Kappa系数均优于传统SVM分类器,表明该方法可应用于高分遥感图像的地表水体提取。 相似文献
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城市居住单元环境质量的高分辨率遥感评价方法研究 总被引：5，自引：0，他引：5
高分辨率遥感影像由于其较高的空间分辨率使得在居住单元的尺度上进行城市环境质量的遥感评价成为可能。所研究的评价方法在选取传统的环境评价指标如绿地景观结构参数、建筑容积率参数基础上，提出了平均可视面积、影像地物交替复杂度以及山体、水体、绿地、道路等外界地物影响力等指标，进一步研究了相关指标的分析方法。最后采用模糊评判的方法得到各参数指标的评判矩阵，进一步获得各居住单元综合指标评价的最终结果。使用厦门市QuickBird遥感影像进行了相关评价方法的实验，对8个典型居住单元的环境评价实验研究表明，利用高分辨率影像进行城市人居环境质量评价是一种成本较低、简便可行的方法。 相似文献
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湖泊沉积物年纹层的研究方法及其意义 总被引：12，自引：4，他引：8
文章总结了前人对湖泊沉积物年纹层类型的划分,并根据年纹层的形成过程和组分特征分为3个大类,即碎屑年纹层、生物成因年纹层(如硅藻年纹层等)和化学成因年纹层(如方解石年纹层、菱铁矿年纹层、黄铁矿年纹层、蒸发盐年纹层等)。介绍了目前应用于湖泊沉积物年纹层研究的主要方法和技术包括:1)新鲜沉积物表面照相、X射线照相技术;2)光学显微镜观察;3)数字化图像分析;4)扫描电子显微镜技术等。而岩相学大薄片是目前年纹层研究工作中应用非常广泛的材料,对目前制作大薄片比较普遍采用的快速冷冻-冷冻干燥和水-丙酮-环氧树脂交换这两种方法进行了介绍并比较了各自的优劣。湖泊沉积物年纹层研究的古环境意义主要体现在两个方面,一是提供了高精度的纹层年代学时间标尺,在诸如气候突变事件的时限、大气14C浓度变化、火山灰层定年、古地磁场长期变化主曲线重建等方面有重要意义;二是年纹层性质研究如年纹层厚度和年纹层微相变化本身所蕴藏的高分辨率古气候环境变化信息,在太阳活动周期、ENSO等气候事件的研究中也有重要意义。最后,文章简单介绍了我国东北龙岗火山区四海龙湾玛珥湖沉积物中年纹层的特征并展望了其研究潜力。 相似文献
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Much of the information in micromorphological thin sections exists at the mesoscopic level. The use of flatbed scanners can improve analysis at this level and aid in preservation of the information. This article describes scanning in both plane and cross‐polarized light and discusses the hardware and software required. © 2002 Wiley Periodicals, Inc. 相似文献
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随着多源遥感影像融合技术的成熟发展,如何提高高分辨率遥感数据的利用效益和使用质量已经成为影响其应用效果的瓶颈问题.针对QucikBird-2高分遥感数据光谱分辨率不足等问题,结合ASTER多光谱遥感数据,引入3种融合方法：主成分分析（PCA）融合、小波PCA融合和基于小波的IHS（色度、亮度、饱和度变换）融合,实现了对多光谱图像和高分辨率图像的融合,得到了多光谱高分辨率影像,使得在增强影像空间分辨率的同时也尽可能地保留了影像的多光谱信息.最后对3种融合方法的结果进行了定性和定量评价. 相似文献
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Twenty thin sections were studied from Cactus Hill, a ca. 20 ka stratified sand dune site in Virginia, USA, with a Clovis and hypothesized pre‐Clovis component. The high‐resolution soil micromorphology investigation focused on testing the integrity of Clovis and pre‐Clovis stratigraphy from one location where there is a high density of artifacts. Site formation processes were dominated by eolian (dune) sand formation. There was also ephemeral topsoil development and associated occupation, along with their penecontemporaneous disturbance and dispersal by scavenging animals (assumed) and localized down‐working by small invertebrate mesofauna (as evidenced by aggregates of fine phytolith‐rich humic soil and fine soil‐coated charcoal fragments). Partial erosion of these occupation soils (deflation?) was followed by successive sand burial. Post‐depositional processes affecting these sand‐buried occupations involved only small‐scale bioturbation and overprinting of clay lamellae, suggesting site stratigraphy has been stable for a long time. Soil micromorphological analysis has defined a difference between occupational units (pre‐Clovis and Clovis) and sterile units found between these units as well as above and below. In summary, according to this analysis, the site appears intact with only minor disturbances affecting the long‐term integrity of the stratigraphy. © 2008 Wiley Periodicals, Inc. 相似文献
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Lineament extraction from multi-resolution satellite imagery: a pilot study on Wadi Bani Malik, Jeddah, Kingdom of Saudi Arabia 总被引：1，自引：0，他引：1
Mohammed H. T. Qari 《Arabian Journal of Geosciences》2011,4(7-8):1363-1371
The study of structural lineaments is important for mineral exploration, geotectonic and geotechnical studies, and for the mitigation of geologic hazards. The present work deals with the extraction of lineaments from satellite imageries of different spatial resolutions as well as the analysis of these extracted lineaments. Wadi Bani Malik area located to the east of Jeddah city on the Red Sea coastal plain is chosen for such a study. Six types of digital satellite imagery data were used in the present study. These comprise satellite imagery of low spatial resolution (LSR) including Landsat MSS of 80-m resolution, Landsat TM of 30-m resolution, and Landsat TM of 25-m resolution; satellite imagery of moderate spatial resolution (MSR) including Landsat ETM+ panchromatic of 15-m resolution and SPOT panchromatic of 10-m resolution; and satellite imagery of high spatial resolution (HSR) including the Indian Remote Sensing satellite IRS data of 5-m resolution. As expected, the analysis of the extracted lineaments from different data sets shows that the imagery data of HSR of the Indian IRS data give the highest frequency of the extracted structural lineaments (N?=?3,235), while the imagery data of LSR of the Landsat MSS data give the lowest frequency of the extracted lineaments (N?=?89). The imagery data of MSR give moderate frequency (N?=?1,643) in average. Due to the present study, it is recommended to use the imagery data of HSR and MSR for the extraction of structural lineaments for detailed and regional studies, respectively. The imagery data of LSR are not recommended for such studies due to the fact that most of the real structural lineaments framework cannot be extracted; accordingly, it is not useful in the analyses of lineaments for geological purposes. 相似文献
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真实土体的细观结构由许多个大小不一的土颗粒团组成,传统四参数随机生长法（QSGS）构建的土体结构土颗粒团比较均匀,与实际情况存在较大的差异。为弥补这一缺陷,考虑土体孔隙率及自相关函数的影响,对传统的四参数随机生长法进行改进,实现了更接近于真实土体的细观结构重构。在此基础上基于格子Boltzmann方法,采用D2Q9模型,通过设置模型入口、出口边界为非平衡态外推格式,左右边界及土颗粒边界为标准反弹格式的边界条件,建立了模拟重构土体细观渗流场的二维模型。同时,针对一算例编制了相应的计算程序,研究了恒定流速入渗情况下重构土体的细观渗流场。研究表明：土体的渗流方向优先选择连通性较好孔隙所形成的通道,流速受控于通道整体连通性的优劣。整体贯通型的通道流动速度较快,部分连通的孔隙中其流动速度相对较慢。即使局部孔隙空间较大,其渗流速度仍取决于是否位于贯通型通道上。 相似文献
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基于CT无损扫描技术的冻土内部物质研究现状与分析 总被引：1，自引：1，他引：0
CT无损动态扫描技术在土壤领域的成功应用,为冻土内部结构及变化的定量化研究提供了有效手段。通过总结和分析现有关于冻土的基于CT断层扫描图像的研究成果,阐明CT扫描技术在冻土研究中的4个关键环节,即冻土样本的制备、冻土CT图像的获取、冻土CT图像处理及分析,并指出在现有CT技术条件下冻土研究中存在的问题,针对性提出了将先进的图像处理技术与高效的图像分析手段和冻土研究相结合的解决方案,为冻土内部结构的定量研究与分析提供技术指导,进而为CT无损动态扫描技术在冻土领域的广泛应用奠定基础。 相似文献
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掺砾黏土在高心墙堆石坝工程中的应用越来越广泛,其拉伸断裂特性对心墙的安全至关重要。将掺砾黏土视作四相复合材料,基于图像处理和随机投放建立了考虑真实砾石形态的细观数值模型,结合物理试验的结果验证了其有效性,并分析了掺砾黏土拉伸断裂的宏细观特性。应力位移曲线的宏观非线性是细观非均质性的体现,砾石的掺入大幅减低了抗拉强度,但提高了峰后抗拉性能;土石界面是微裂缝发展的源头,拉伸断裂是一个微裂缝萌生、扩展以至汇集形成宏观裂缝的过程;拉伸断裂发生在一个区域,即断裂过程区,该区域的形成与砾石的随机分布有关。最后,采用数值试验分析了随机砾石投放和掺砾量对掺砾黏土宏细观力学行为的影响。 相似文献
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X‐ray tomography of tsunami deposits: Towards a new depositional model of tsunami deposits 
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下载免费PDF全文 X‐ray computed microtomography is used to obtain high resolution imagery of a historical tsunami deposit in Andalusia, Spain (1755 Lisbon tsunami). The technique allows characterization of grain‐size distribution, structures, component analysis and sedimentary fabric of fine‐grained unconsolidated tsunami deposits at resolutions down to particle scale. The results are validated by comparing to data obtained using other techniques such as laser diffraction, anisotropy of magnetic susceptibility and X‐ray microfluorescence on the same deposits. Specific technical details such as sampling, scanning and image processing methods, and further improvements are addressed. The use of X‐ray computed microtomography provides new insights into the stratigraphy of the deposits and gives access to significantly more detailed view of key sedimentary features such as mudlines, rip‐up clasts, crude laminations, convolutions, floating outsized clasts and contacts between successive units. This analysis of the 1755 tsunami deposits using X‐ray computed microtomography allows the proposal of new hypotheses for the sedimentary processes forming tsunami deposits. Deposition by settling is limited and the section analysed here is dominated by a high shear stress leading to the development of traction carpets, with laminated mudlines corresponding to the basal frictional region of these carpets. The onset of the tsunami backwash is marked by a micro‐vortex resembling Kelvin–Helmoltz instabilities. 相似文献
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Pan-sharpening is the process of transferring the spatial resolution of panchromatic (PAN) image to a multispectral (MS) image for producing a single image with high spatial detail and rich spectral information. In this study, PAN and MS imagery of Quickbird-2 and Landsat-8 are fused separately, using ten different pan-sharpening methods such as principal component analysis (PCA), modified-intensity hue saturation (M-IHS), multiplicative, brovey transform (BT), wavelet-principal component analysis (W-PCA), hyperspectral color space (HCS), high-pass filter (HPF), Gram-Schmidt (GS), Fuze Go, and non-subsampled contourlet transform (NSCT). The effectiveness of these techniques is assessed and compared by qualitative analysis and 14 quantitative analysis methods including bias, correlation coefficient (CC), difference in variance (DIV), relative dimensionless global error in synthesis (ERGAS), universal image quality index (Q), relative average spectral error (RASE), root mean square error (RMSE), structural similarity index method (SSIM), signal-to-noise ratio (SNR), peak SNR (PSNR), spatial correlation coefficient (SCC), image entropy (E), and gradient and quality with no reference image (QNR). The results of both analysis types show that the Fuze Go and NSCT produced the best fused image with high spatial detail and rich spectral information followed by the HPF and GS. 相似文献
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针对数字全景钻孔摄像系统获取的实测图像,提出了一种基于颜色特征的数字式钻孔图像溶隙结构识别方法。利用岩层中的典型结构,如土质层、溶隙在颜色上与普通岩石具有较大差异性的特点,首先建立了一个自适应HSV颜色空间溶隙结构检测模型,利用该模型获取溶隙结构的二值化图像;对该二值化图像进行滤波处理;然后从处理后的二值化图像进行分区像素密度统计来确定土质层或溶隙区域的深度、面积及方位角等信息,从而实现数字式钻孔图像中溶隙结构的自动识别。通过对大量数字式钻孔图像进行试验并与对应的钻孔雷达图像进行结果对比表明,其方法能对全孔图像的溶隙和土质层进行快速、准确地自动化检测与定位,为钻孔图像岩体结构的自动识别与工程应用提供了一种新的可靠方法。 相似文献
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An extreme ice storm in January 1998 deposited up to 100 mm of ice and resulted in significant forest damage across eastern North America. Average crown loss of over 75% was recorded in large areas of eastern Ontario and southern Quebec. A primary question that arose following the storm was: can forest damage be effectively assessed using remote sensing and other available environmental data? This paper presents two contrasting studies to address this question. The first involves damage modelling at a local scale in an unmanaged forest using spectral and spatial information in high-resolution airborne imagery. Results of field data analyses are also given that show relations between damage and forest structure and composition as well as changes in forest structure that occurred in the years following the storm. The second study involves regional scale damage mapping in managed and unmanaged forests of eastern Ontario using medium resolution satellite imagery and other environmental data. In comparison of several image classification and data interpolation methods, the best damage map was produced using a neural network classifier and a mix of Landsat and environmental data. The methods and results presented in this paper form the basis for ongoing long-term temporal study of damage impacts on forest condition. 相似文献
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生物喀斯特及其微形态研究 总被引：16，自引：0，他引：16
生物喀斯特是由生物作用和岩石的可溶性共同作用形成的特殊形态及其过程，本文在回顾和讨论了生物喀斯特的产生、定义、概念及其研究内容后，着重讨论了生物喀斯特微形态研究的概念、意义和研究方法、指出了生物喀斯特微形态研究是具有独特研究对象和方法以及重要理论实践意义的研究体系，提出了生物喀斯特微形态学的概念。 相似文献
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卫星遥感TM及SAR数据用于山区构造格局分析——以西藏墨脱地区为例 总被引：2，自引：0，他引：2
西藏墨脱地区山高路险，植被覆盖严重。区域地质调查中卫星遥感TM和SPOT光学图像受到植被干扰，地质构造露头不清；而微波侧视雷达图像（SAR）由于受到高山地形影响，信号遮蔽，控制点的精确选取和遥感地质解译也十分困难。研究中采用DEM（数字高程模型）模拟SAR图像的方法，利用模拟SAR图像对原始雷达图像进行控制点选取和影像正射校正，通过TM图像和SAR图像的正射影像处理以及二者的影像数据融合，并利用DEM进行三维构像，最大限度地发挥了TM图像和SAR图像的影响优及二者的影像数据融合，并利用DEM进行三维构像，最大限度地发挥了TM图像和SAR图像的影像优势，用于测区区域地质和构造解译，取得了较好效果。 相似文献
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高分辨率图像是人们一直追求的目标,超分辨率图像重建技术就是人们获取高分辨率图像的一种很重要的方法。研究了超分辨率贝叶斯方法,该方法利用全波段增强多光谱遥感影像,结合传感器特性模拟了全波段和多波段影像的观测过程。这种方法使全波段数据与多光谱波段数据自动对齐,成功地保留了光谱信息,实现了遥感数据信息的高保真,进而增强了空间分辨率。以IKONOS全波段和多波段影像为例进行了深入地探讨,并对自动融合的结果进行了定性和定量分析。 相似文献
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为了进一步研究加肋土工膜拉拔试验作用机制,通过室内拉拔试验和粒子图像测速(PIV)分析,研究不同工况下（加肋高度和温度）加肋土工膜与砂土界面的力学性质以及衬垫系统内部颗粒的位移场和速度场分布。拉拔试验结果表明,不同的加肋高度和温度对界面的稳定性有着深刻的影响,极限拉拔阻力随着加肋高度的增加和温度的降低而增大。通过细观分析得出加肋土工膜和砂土界面附近砂土会形成间接影响区。影响区内部的砂土位移和速度比周围砂土颗粒位移和速度大,这是因为肋块在拉拔过程中挤压其左侧的颗粒或带动其整体移动。并且肋块之间的影响区会相互影响扩散,因此对砂土颗粒形成加固作用。试验结果和PIV分析表明,温度和加肋高度对间接影响区有着显著的影响,从而对加肋土工膜与砂土界面的整体稳定性产生影响。 相似文献