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81.
赵珍梅 《地质与勘探》2011,47(5):748-754
本文在分析中国区域地质特征的基础上,以ETM卫星影像为信息源,依据地质学家李四光确定地块的原则和地壳运动规律,根据ETM影像的色调、影纹和地貌等特征,建立了地块划分准则,以此为依据将中国大陆划分成28个大地块,编制了中国大陆地块盆地分布图。本文在分析地壳运动规律和各地块的运动特征的基础上,提出了各地块之间进行着规律性的相互推挤运动,且北部地块向南推移和就位,西部地块向东推移和就位的新观点。本文通过分析已知大中型金属矿床的统计分布规律:大部分矿床分布在地块东、南侧,地块运动方向的前锋,尤其是弧形拼合带前缘;提出了在块体碰撞带或块内大构造带南找大矿的新思路。  相似文献   
82.
根据蚀变岩的TM波谱特征,在日土县以东地区进行了蚀变岩遥感信息提取。通过对研究区羟基(OHA)和铁染(FCA)两种异常的分析,为下一步地质调查工作提出建议。  相似文献   
83.
In general,topographic shadow may reduce performance of forest mapping over mountainous regions in remotely sensed images.In this paper,information in shadow was synthesized by using two filling techniques,namely,roifill and imfill,in order to improve the accuracy of forest mapping over mountainous regions.These two methods were applied to Landsat Enhanced Thematic Mapper (ETM +) multispectral image from Dong Yang County,Zhejiang Province,China.The performance of these methods was compared with two conventi...  相似文献   
84.
胡昌苗  张微  冯峥  唐娉 《遥感学报》2014,18(2):267-286
全球地表覆盖遥感制图与关键技术研究项目要求对两个基准年度(2000年,2010年)的全球覆盖30 m分辨率遥感数据进行辐射处理,转换到地表反射率,数据以Landsat TM/ETM+为主,HJ-1A/B CCD数据为补充。海量数据中有些不适宜进行绝对大气校正,为了保证全球覆盖,对这些数据设计开发了一套自动的相对辐射处理及精度验证流程算法,利用相邻数据重叠区域进行相对辐射校正的方式,将数据由Oigital Number(DN)值直接转换为地表反射率,精度验证以MODIS地表反射率产品MOD09GA作为参考,比较对应波段数据的相对一致性,算法采用了图像分块处理技术及OpenMP加速技术提高效率,实际应用结果表明该算法流程可以满足项目对辐射处理精度、速度及自动化程度的要求。  相似文献   
85.
李大成  唐娉  胡昌苗  郑柯 《遥感学报》2014,18(2):307-319
Landsat 5卫星较低的时间分辨率(16天)使得其很难获得大区域的、时相一致的清晰影像数据集。本文发展了一种基于半物理模型的时空融合算法-即乘性调制融合算法,并借助多时序的MODIS反射率数据来生成多时相的Landsat TM/ETM+反射率合成影像,经镶嵌后得到区域尺度的高时空分辨率地表反射率数据集(Landsat TM/ETM+)。本文利用吉林省2006年—2011年的Landsat 5 TM地表反射率数据以及500 m的MOD09A1反射率产品来生成3个时相的Landsat 5 TM反射率合成数据,从而获得研究区在上述时相下地表反射率数据的镶嵌图。初步分析表明,所生成的Landsat 5 TM反射率数据的光谱分布特征与MOD09A1反射率数据较为一致,且图像在整体上光谱特征的连续性较好。  相似文献   
86.
Abstract

In the Hindukush, Karakoram and Himalaya (HKH) region of Pakistan, many glaciological variables are still not known due to the remoteness and harsh weather conditions of the area. A remote sensing technique is therefore applied to map the snow zonation in the HKH region. Landsat 7 ETM+ data for the year 2003 are used in this study. Image classification and image processing techniques are applied to map, for the first time, the major snow zones in the HKH region. Six classes are identified: the results show that the area covered by the highest-altitude snow (Snow I), lower-altitude snow (Snow II), bare ice, debris-covered ice, wet snow and shadow is 21 529.42, 22 472.58, 8696.41, 8038.75, 12 159.37 and 7322.30 km2, respectively. The study also indicates that the equilibrium line altitude (ELA) lies between 5000 and 5500 m above sea level, with an accumulation area ratio (AAR) of 0.60.

Citation Butt, M.J., 2013. Exploitation of Landsat data for snow zonation mapping in the Hindukush, Karakoram and Himalaya (HKH) region of Pakistan. Hydrological Sciences Journal, 58 (5), 1088–1096.  相似文献   
87.
Four data fusion methods, principle component transform (PCT), brovey transform (BT), smoothing filter-based intensity modulation (SFIM), and hue, saturation, intensity (HSI), are used to merge Landsat—7 ETM+ multispectral bands with ETM+ panchromatic band. Each of them improves the spatial resolution effectively but distorts the original spectral signatures to some extent. SFIM model can produce optimal fusion data with respect to preservation of spectral integrity. However, it results the most blurred and noisy image if the coregistration between the multispectral and pan images is not accurate enough. The spectral integrity for all methods is preserved better if the original multispectral images are within the spectral range of ETM+ pan image.  相似文献   
88.
Tourism is Nepal's largest industry, giving people in rural areas an alternative to subsistence farming. Tourism can have an impact on the forest cover of a region as trees provide firewood for cooking and heating and timber for building accommodation. In 1986 the Annapurna Conservation Area Project was established to ensure that tourism was managed more sustainably, which includes minimising its impact on the forest cover. This study assesses the impacts of tourism on the forest cover in the Annapurna region by comparing Landsat images from 1999 to 2011. This was achieved through spectral classification of different land cover and by assessing the change in forest cover in relation to increasing distances from tourism villages. A major problem with remote sensing in mountainous regions such as Nepal is shadow caused by the relief. This issue was addressed by only assessing areas which were free from shadow, which in effect meant a sample was used rather than the whole study region. The results indicate that there has been an 8 percent reduction in overall forest extent, but this change varies by region. In the northern, drier regions there has been a net increase in forest cover, while in the southern regions there has been a net reduction in forests. The influence of tourism facilities on forest is also variable. Around each of the tourism villages sampled there was a general trend of forest removal decreasing as the distance from each village increased, which indicates tourism does have a negative impact on forests. However, there was an opposite trend in the northern villages that were well inside the conservation area.  相似文献   
89.
Landsat-7机载扫描行校正器(Scan Line Corrector,SLC)失效后的ETM+影像(SLC-OFF影像)约有22%的数据缺失,严重限制了该影像在冰川研究中的应用,特别对长期缺乏高质量遥感影像的高亚洲地区冰川运动连续监测产生较大影响。以Karakoram 中部最大的锡亚琴冰川为例,初步评估了Landsat-7 ETM+SLC-OFF影像在山地冰川表面流速提取方面的适用性和可行性。选取2009年和2010年两景SLC-OFF影像,运用局部直方图匹配法(Local Linear Histogram Match,LLHM)和加权线性回归法(Weighted Liner Regression,WLR)修复缺失数据条带,并利用亚像元互相关方法对修复后两景影像进行冰川表面流速估算。结果表明,LLHM和WLR两种方法均能有效修复冰川区Landsat-7 SLC-OFF影像,其冰流估算结果与同期Landsat-5TM 影像的冰流结果较为一致,三者冰流速估算精度分别为±5.9m ·a-1、±6.3m ·a-1和±4.0m ·a-1,验证了Landsat-7 SLC-OFF 影像在山地冰川流速监测中的应用潜力。  相似文献   
90.
ETM+影像IHS融合算法改进及其土地覆盖分类实验比较   总被引:5,自引:2,他引:3  
在总结PCA、IHS融合算法优缺点的基础上,发展了一种改进的IHS融合算法。利用HPF、Brovery、PCA、IHS及改进的IHS融合算法对ETM+全色和多光谱影像进行了融合实验。通过定性、定量分析比较融合影像的质量,并分别对融合后影像和原始影像进行土地覆盖非监督分类实验。选取原始影像和非监督分类精度最高的一种融合影像进行监督分类实验与比较,发现无论是非监督分类还是监督分类,改进的IHS融合影像精度均较高。  相似文献   
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