排序方式： 共有35条查询结果，搜索用时 390 毫秒
1.
Desertification is a severe stage of land degradation, manifested by “desert-like” conditions in dryland areas. Climatic conditions together with geomorphologic processes help to mould desert-like soil surface features in arid zones. The identification of these soil features serves as a useful input for understanding the desertification process and land degradation as a whole. In the present study, imaging spectrometer data were used to detect and map desert-like surface features. Absorption feature parameters in the spectral region between 0.4 and 2.5 μm wavelengths were analysed and correlated with soil properties, such as soil colour, soil salinity, gypsum content, etc. Soil groupings were made based on their similarities and their spectral reflectance curves were studied. Distinct differences in the reflectance curves throughout the spectrum were exhibited between groups. Although the samples belonging to the same group shared common properties, the curves still showed differences within the same group.Characteristic reflectance curves of soil surface features were derived from spectral measurements both in the field and in the laboratory, and mean reflectance values derived from image pixels representing known features. Linear unmixing and spectral angle matching techniques were applied to assess their suitability in mapping surface features for land degradation studies. The study showed that linear unmixing provided more realistic results for mapping “desert-like” surface features than the spectral angle matching technique. 相似文献
2.
探索利用高光谱数据的岩性填图新方法是遥感地质应用领域的重要需求之一。本文运用随机森林方法和EO-1Hyperion高光谱数据,对新疆塔里木西北部柯坪地区的局部区域进行岩性分类,并对相关问题进行分析。分别利用光谱特征以及加入光谱一阶导数特征进行岩性分类,并对不同特征对岩性分类的重要性进行分析,同时与现有的基于光谱角制图方法(SAM)进行比较。结果表明,与SAM方法相比,随机森林方法得到了更高精度的岩性分类结果,是一种有效可行的岩性分类方法。根据特征重要性的排序,蓝绿光波段、短波红外波段以及相应的一阶导数特征对研究区Hyperion数据的沉积岩岩性分类贡献更大。 相似文献
3.
4.
A Comparative Study of Landsat‐7 and Landsat‐8 Data Using Image Processing Methods for Hydrothermal Alteration Mapping 
下载免费PDF全文
下载免费PDF全文 Feizollah Masoumi Taymour Eslamkish Mehdi Honarmand Ali Akbar Abkar 《Resource Geology》2017,67(1):72-88
Comparing spaceborne satellite images of Landsat‐8 Operational Land Imager (OLI) and Landsat‐7 Enhanced Thematic Mapper plus (ETM+) was undertaken to investigate the relative accuracy of mapping hydrothermal alteration minerals. The study investigated the northern part of Rabor, which contains copper mineralization occurrences, and is located in the Kerman Cenozoic magmatic assemblage (KCMA), Iran. Image processing methods of band ratio, principal component analysis (PCA), and spectral angle mapper (SAM) were used to map the distribution of hydrothermally altered rocks associated with the porphyry copper mineralization. The band ratio combination of both sensors for mapping altered areas showed similar outcomes. PCA exposed variations in the spatial distribution of hydroxyl‐bearing minerals. The representation of hydrothermal areas using OLI data was more satisfactory than when using ETM+ data. SAM analysis found similar results for mapping hydroxyl‐bearing zones. Verification of the results came through ground investigation and laboratory studies. Rock samples (n = 56) were collected to validate results using thin sections, X‐ray diffraction (XRD) and spectral analyses. Field observations and laboratory analysis revealed that phyllic and propylitic alterations dominate the alteration zones in the study area. Argillic and iron oxides/hydroxides alterations were observed to a lesser degree. The results indicate that alteration maps prepared by OLI data using PCA for visual interpretation are more suitable than those of ETM+ due to a higher radiometric resolution and lower interference between vegetation and altered areas. As the spectral bandwidth of ETM+ band 7 covers absorption feature of propylitic alteration, better mapping of propylitic alterations is achieved using ETM+ data. 相似文献
5.
应用多光谱ASTER数据对ETM遥感异常的定性判别研究——以东昆仑五龙沟为例 总被引：5，自引：0，他引：5
文中讨论了新的找矿参数——蚀变遥感异常的地质基础和光谱前提,在矿床地质学和蚀变矿物光谱参数特征的基础上,编制了一张用于遥感异常提取及对其地质解释的表格。ETM遥感异常提取技术已在全国推广,ASTER数据可以在三个方面对已推广的ETM起到重要的补充作用：1.利用短波红外增设的波段,对某些矿致异常区分其矿化（矿床）类型;2.利用增设的热红外波段区分某些岩性;3.可有助于解决ETM因第7波段太宽而产生的许多疑难问题。本文以东昆仑五龙沟为例讨论了ASTER对于解决ETM遥感异常性质判别困难方面的作用。 相似文献
6.
采用卫星遥感方法制作的数字正射影像是获取基础空间信息最快速、高效的手段,利用高精度卫星遥感成图,处理速度快、工艺简便、图像清晰,而且精度达到成图要求。本文介绍了以高分辨率的QuickBird卫星影像为研究对象,利用ERMapper图像处理系统进行图像的几何校正、全色与多光谱数据融合方法与过程。 相似文献
7.
物探测量内业的一些辅助性工作,由于涉及的软件及格式多种多样,需要多种不同的软件和繁杂的转换过程。本文介绍了如何利用Global Mapper软件来轻松的实现GPX转CAD、文本坐标转GPX、矢量数据转KML。同时对Global Mapper软件提供的制作晕染图与转换遥感及GIS数据功能做了简单的介绍。 相似文献
8.
二滩、官地库区土地覆盖类型图制作方法研究 总被引：2，自引：0，他引：2
利用航空彩红外正射影像镶嵌图,用光谱角分类与目视解译相结合的方法,对二滩、官地库区进行土地利用调查工作,取得了较好的效果。 相似文献
9.
为研究如何利用遥感技术进行蛇绿岩岩矿信息识别和提取,以藏东罗布莎蛇绿岩为例,基于ETM和ASTER遥感数据,分别采用比值法和主成分分析法提取羟基类(蛇纹石、绿泥石)和铁染类(磁铁矿、橄榄石)矿物信息;利用纯净像元指数法(pure pixel index,PPI)提取端元波谱,结合地面已知岩性信息,分别采用光谱角分类法(spectral angle mapping,SAM)和波谱特征拟合法(spectral feature fitting,SFF)识别纯橄岩和橄榄岩,研究了罗布莎蛇绿岩及其主要蚀变矿物的空间分布特征.经过对比分析可知,用多种方法、多种数据提取的岩矿信息可以相互验证;提取出的纯橄岩和橄榄岩与所提取的羟基类和铁染类蚀变遥感异常信息有较好的空间重叠,且与地面调查结果基本吻合.研究表明,该方法用于蛇绿岩遥感岩矿信息提取是可行的,并取得较好的地质效果. 相似文献
10.
地面成像光谱数据的田间杂草识别 总被引：5，自引：0，他引：5
地面成像光谱数据兼具高光谱分辨率与高空间分辨率,在田间杂草识别中具有很好的应用前景。目前基于机器视觉的杂草识别方法以形状特征为主,当作物杂草形态相似时识别的困难和利用高光谱特征以像元为单元识别时效率较低,不利于实时自动化除草,因此,本文提出一种综合面向对象与高光谱特征匹配的杂草识别方法,在对作物杂草对象样本的形状特征和光谱曲线提取分析的基础上,建立基于形状特征规则与光谱角匹配的植物对象识别决策树,用于识别实验田中的作物杂草对象。实验结果表明,当场景中某些不同种类植物对象的形态相似时,基于形状特征规则与光谱角匹配的杂草识别方法可借助高光谱特征精细区分植物对象的种类,且在形状特征规则约束下使用高光谱特征匹配法识别植物对象,可克服"同物异谱"和"同谱异物"现象带来的不确定性,该方法识别精度可优于仅使用光谱角匹配法的情况,并优于使用颜色和形状分析技术的情况。 相似文献