河南祁雨沟金矿及外围高植被区遥感找矿预测

应用ENVI4.8软件,对河南嵩县祁雨沟金矿及外围ETM+遥感数据通过主成分分析、彩色合成、直方图拉伸、监督分类等方法,成功地提取了高植被覆盖区遥感影像上金的植物地球化学异常信息。利用卷积滤波和形态学分析方法进行线性构造解译,利用计盒维数法求得研究区的线性构造分维值,得出本区线性构造具有良好的统计自相似性和分形特征。比较线性构造分维等值线图和植物地球化学异常图可知,线性构造集中区与植被异常区基本吻合,区内已知85%以上的矿点分布于植被异常和线性构造集中区。综合分析地层岩性、岩浆岩、矿点、线性构造分维等值线特征和遥感植被异常特征等信息,圈出了三级9个找矿靶区。     

遥感技术在多龙铜矿预测区成矿预测中的应用

多龙铜矿集区位于班公湖～怒江成矿带西段,区内已知的典型矿床为多不杂和波龙斑岩型铜矿,是大型的铜多金属矿床,其成矿背景复杂,找矿潜力巨大。利用ETM+遥感影像,对研究区进行构造解译和矿化蚀变信息提取的工作,再结合区域地质、物探、化探等信息进行综合找矿分析,并结合已知矿床点,圈定出二处遥感找矿远景区,为矿产资源潜力评价和成矿预测提供了重要的信息和依据。     

ETM+数据在甘肃省肃北县黑刺沟一带蚀变遥感异常信息提取中的应用

遥感卫星的多光谱数据应用于找矿已取得显著的成效,ETM+数据因涵盖波长范围宽、波段多、价格合理等因素,而逐渐广泛应用。笔者利用ETM+数据到黑刺沟一带进行蚀变遥感异常提取,提取的蚀变异常与野外地质情况吻合性好,分别提取了铁染和黏土化蚀变遥感异常,并采用了掩膜技术消除了云、冰雪、盐碱地、盐碱滩和植被的干扰。     

运用LANDSAT ETM+和ASTER数据进行岩性分类

本文评价了运用ASTER和LANDSAT ETM+数据进行岩性制图的性能。分别利用ASTER数据不同波段区图像及其组合,以及ETM+数据进行岩性分类,并探讨了将ASTER和ETM+数据叠加在一起进行了岩性分类; 利用现有地质图对所有分类结果进行了定量评价。结果表明,ASTER数据不同波段的岩性识别能力不同,并且较ETM+数据能更准确地识别岩性。更重要的是,把ASTER与ETM+数据结合在一起进行岩性分类,可获得比用任一数据单独分类更高的分类精度,表明二者的光谱特征具有一定的互补性。     

中、高分辨率遥感数据在铀成矿有利区评价中的综合应用——以新疆库鲁克塔格断隆为例

塔里木盆地北缘是近几年核工业系统开展铀矿勘查的重点区域之一,但位于其东北缘的库鲁克塔格断隆的铀矿地质工作相对薄弱。根据库鲁克塔格断隆区的铀矿找矿特点,开展了基于中等分辨率ETM和高分辨率QuickBird遥感数据的铀成矿环境、蚀变信息提取、构造解译等综合应用研究,对铀成矿有利区段进行了新的评价,选出了2片铀成矿有利区,为今后进一步的铀矿勘查提供了遥感地质依据。     

ETM与SPOT影像融合方法比较和评价——以庐山及其周边区域为例

高空间分辨率影像与多光谱影像融合,为影像处理提供了更加丰富的资源,有利于进行影像的分析和制图。本文以庐山及其周边区域的2009年5月11日Landsat ETM+与2009年5月6日SPOT 5影像数据为例,对典型的融合方法进行了对比评价。融合方法包括加权融合法,IHS变换,改进的IHS变换,高频调制融合法(频域采用Butterworth滤波器,指数滤波器),HSV变换,Brovey变换,CN变换,PC变换,Gram-Schmidt变换11种方法。评价指标为相关系数、信息熵、标准差、平均梯度、相对偏差、标准偏差。结果表明,不同的融合结果突出的侧重点不同。加权融合法、Gram-Schmidt变换,PC变换方法突出了影像的信息量丰富度、清晰度,提高空间分辨率能力。CN波谱锐化,改进的IHS变换,BW0高频调制融合,指数高频调制融合方法光谱保真度较好。改进的IHS变换,BW0高频调制融合,CN波谱锐化,指数高频调制融合法在空间分辨率及光谱保真度、清晰度、信息丰富度方面的能力较均衡。     

基于Landsat TM/ETM+遥感数据的福州热环境研究

以福建省福州市为研究区,使用1994年5月12日Landsat TM、2002年3月7日LandsatETM+和2009年3月10日Landsat TM数据,采用普适性单通道算法对研究区进行地表温度反演算,反演得出福州地面温度的分布情况,并根据研究结果对福州市热环境空间分布格局及动态演变过程进行监测分析.研究结果表明:福州市存在明显的城市热岛现象,不同时相遥感数据反演得到的福州市地表温度的空间分布趋势基本一致;城区地表温度明显高于郊区,水体温度最低.1994年福州市热岛中心分布范围较小;1994—2002年间福州市高温区域明显增加,主要分布在城区建筑物比较密集的区域和裸地区域;2002—2009年间高温区增加得比较缓慢,同1994年和2002年相比,2009年城区范围内大面积高温区减少且分布比较破碎.     

基于局部相关分析法的ETM+影像修复方法研究

Landsat-7上搭载的专题扫描仪(ETM+)上的扫描行校正器(SLC)在2003年发生故障,导致影像出现坏行,丢失了约25%的数据。由于数据本身仍保持了良好的辐射和几何特性,且同一区域不同时相影像上坏行出现的位置具有随机性,使得使用同一区域不同时相的ETM+影像进行交叉修复成为可能。该文在总结现有修复方法的基础上,提出了一种采用相近时相、相同位置影像对ETM+影像进行修复的方法。首先利用两景影像中的准不变特征点(PIFs),以待修复影像为目标,对待填充影像进行相对辐射校正,消除不同时相影像间由于大气状况等外源差异导致的像元亮度值差异。然后运用局部相关分析法对待填充影像进行变换:构建一种同时考虑光谱距离和空间距离的权重系数,根据邻近光谱相似点在两个时相上的变化量对待填充影像进行变换。实验证明,该方法修复效果优于传统的局部回归法。     

近50年黑河流域的冰川变化遥感分析(英文)

The Heihe River Basin is the second largest inland river basin in Northwest China and it is also a hotspot in arid hydrology, water resources and other aspects of researches in cold regions. In addition, the Heihe River Basin has complete landscape, moderate watershed size, and typical social ecological environmental problems. So far, there has been no detailed assessment of glaciers change information of the whole river basin. 1:50,000 topographic map data, Landsat TM/ETM+ remote sensing images and digital elevation model data were used in this research. Through integrated computer automatic interpretation and visual interpretation methods, the object-oriented image feature extraction method was applied to extract glacier outline information. Glaciers change data were derived from analysis, and the glacier variation and its response to climate change in the period 1956/1963–2007/ 2011 were also analyzed. The results show that:(1) In the period 1956/1963–2007/2011, the Heihe River Basin's glaciers had an evident retreat trend, the total area of glaciers decreased from 361.69 km2 to 231.17 km~2; shrinking at a rate of 36.08%, with average single glacier area decrease 0.14 km~2; the total number of the glaciers decreased from 967 to 800.(2) Glaciers in this basin are mainly distributed at elevations of 4300–4400 m, 4400–4500 m and 4500–4600 m; and there are significant regional differences in glaciers distribution and glaciers change.(3) Compared with other western mountain glaciers, glaciers retreat in the Heihe River Basin has a higher rate.(4) Analysis of the six meteorological stations' annual average temperature and precipitation data from 1960 to 2010 suggests that the mean annual temperature increased significantly and the annual precipitation also showed an increasing trend. It is concluded that glacier shrinkage is closely related with temperature rising, besides, glacier melting caused by rising temperatures greater than glacier mass supply by increased precipitation to some extent.     

Comprehensive study of the biophysical parameters of agricultural crops based on assessing Landsat 8 OLI and Landsat 7 ETM+ vegetation indices

For three agricultural crop types, winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and canola (Brassica napus L.), we estimated biophysical parameters including fresh and dry biomass, leaf area index (LAI), and vegetation water content, for which we found the equivalent water thickness (EWT), fuel moisture content per fresh weight (FMC_FW), and fuel moisture content per dry weight (FMC_DW). We performed these estimations using data from the newly launched Landsat 8 Operational Land Imager (OLI) sensor, as well as its predecessor the Landsat 7 Enhanced Thematic Mapper Plus (ETM+). Progress in the design of the new sensor (i.e., Landsat 8), including narrower near-infrared (NIR) wavebands, higher signal-to-noise ratio (SNR), and greater radiometric resolution highlights the necessity to investigate the biophysical parameters of agricultural crops, especially compared to data from its predecessor. This study aims to evaluate vegetation indices (VIs) derived from the Landsat 8 OLI and the Landsat 7 ETM+. Both the Landsat 8 OLI and Landsat 7 ETM+ VIs agreed well with in-situ data measurements. However, the Landsat 8 OLI-derived VIs were generally more consistent with in situ data than the Landsat 7 ETM+ VIs. We also note that the Landsat 8 OLI is better able to capture the small variability of the VIs because of its higher SNR and wider radiometric range; in addition, the saturation phenomenon occurred earlier for the Landsat 7 ETM+ than for the Landsat 8 OLI. This indicates that the new sensor is better able to estimate the biophysical parameters of crops.