排序方式： 共有17条查询结果，搜索用时 515 毫秒
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新疆阿尔金地区位于阿尔金成矿带,属于干旱半干旱高寒山区景观区,该区成矿条件优越,但自然地理条件较差,基岩裸露利于蚀变矿物准确提取,采用CASI/SASI航空高光谱遥感进行蚀变矿物遥感信息提取及找矿预测,可以克服自然条件影响,降低成本。本文以CASI/SASI航空高光谱遥感数据为数据源,以干旱半干旱高寒山区景观区为研究背景,评价研究该区CASI/SASI航空高光谱蚀变矿物遥感信息提取效果,通过野外地质调查,发现了镍、铁、钴、钒、钛、铜等元素多金属矿化线索,并最终圈定了YC01和YC02等两处找矿预测区。说明CASI/SASI航空高光谱遥感在干旱半干旱高寒山区蚀变矿物遥感信息提取效果显著。 相似文献
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Jochem Verrelst Gertjan W. Geerling Karle V. Sykora Jan G.P.W. Clevers 《International Journal of Applied Earth Observation and Geoinformation》2009
Combined optical and laser altimeter data offer the potential to map and monitor plant communities based on their spectral and structural characteristics. A problem unresolved is, however, that narrowly defined plant communities, i.e. plant communities at a low hierarchical level of classification in the Braun-Blanquet system, often cannot be linked directly to remote sensing data for vegetation mapping. We studied whether and how a floristic dataset can be aggregated into a few major discrete, mappable classes without substantial loss of ecological meaning. Multi-source airborne data (CASI and LiDAR) and floristic field data were collected for a floodplain along the river Waal in the Netherlands. Mapping results based on floristic similarity alone did not achieve highest levels of accuracy. Ordination of floristic data showed that terrain elevation and soil moisture were the main underlying environmental drivers shaping the floodplain vegetation, but grouping of plant communities based on their position in the ordination space is not always obvious. Combined ordination-based grouping with floristic similarity clustering led to syntaxonomically relevant aggregated plant assemblages and yielded highest mapping accuracies. 相似文献
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Knowledge of spatio-spectral heterogeneity within multisensor remote sensing images across visible, near-infrared and short wave infrared spectra is important. Till now, little comparative research on spatio-spectral heterogeneity has been conducted on real multisensor images, especially on both multispectral and hyperspectral airborne images. In this study, four airborne images, Airborne Thematic Mapper, Compact Airborne Spectrographic Imager, Specim AISA Eagle and AISI Hawk hyperspectral airborne images of woodland and heath landscapes at Harwood, UK, were applied to quantify and evaluate the differences in spatial heterogeneity through semivariogram modelling. Results revealed that spatial heterogeneity of multisensor airborne images has a close relationship with spatial and spectral resolution and wavelength. Within the visible, near-infrared spectra and short wave infrared spectra, greater spatial heterogeneity is generally observed from the relatively longer wavelength in short wave infrared spectra. There are dramatic changes across the red and red edge spectra, and the peak value is generally examined in the red middle or red edge wavelength across the visible and near-infrared spectra for vegetation or non-vegetation landscape respectively. In all, for real multisensor airborne images, the change in spatial heterogeneity with spatial resolution will accord with the change of support theory depending on whether dramatic change exists across the corresponding wavelength. Besides, if with close spatial resolution, the spatial heterogeneity of multispectral images might be far from the overall integration of these bands from the hyperspectral images involved. A comparative assessment of spatio-spectral heterogeneity using real hyperspectral and multispectral airborne images provides practical guidance for designing the placement and width of a spectral band for different applications and also makes a contribution to the understanding of how to reconcile spatial patterns generated by multisensors. 相似文献
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盐沼植被光谱特征的间接排序识别分析 总被引：1，自引：0，他引：1
运用ASD地物光谱仪,采用12个小型机载成像光谱仪(CASI)默认的植被波段组,以上海崇明东滩自然保护区的盐沼植物群落为对象,应用主成分分析法和相关分析研究了不同群落光谱特征与生态环境因子之间的关系。结果表明:运用PCA间接排序法能够识别盐沼植被中光滩、海三棱藨草群落、芦苇群落和互花米草群落等光谱特征;绝大多数盐沼植物的群落组成与所选波段的光谱特征之间有显著的相关关系;可见光和近红外波段数据可以分别识别低盖度的海三棱藨草群落和高盖度的互花米草和芦苇群落;对光谱反射率影响最大的生态环境因子是植物群落的高度和盖度,而高程和其它环境因子的影响次之。 相似文献
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森林生物化学与CASI高光谱分辨率遥感数据的相关分析 总被引：38，自引：3，他引：38
该文介绍了利用光谱范围约 417— 80 0nm的航空高光谱分辨率数据估计森叶族叶化学成分浓度的分析方法。沿横跨美国俄勒冈州中西部收集 6个研究立地上的小型机载成象光谱仪 (CASI)数据。 3个族叶化学成分 [总叶绿素 (TC)、全氮 (TN)和全磷 (TP) ]从相同的研究立地取样并在实验室测定。使用多元统计和光谱微分技术评价CASI数据用于估计冠层生化浓度的潜力和效率。 12个族叶化学成分样本被测定 ,并同时在相同立地上提取CASI图象数据。 7个单回归模型被用来探索单波段和植被指数与 3个化学成分的线性与非线性相关关系及预测效果。光谱微分技术被用来压缩背景噪音对目标光谱的影响。利用CASI原始光谱、一阶和二阶微分光谱数据和逐步回归分析来预测TC、TN和TP。结果表明采用光谱微分技术能显著地改善由拟合度 (R2 )和均方根差(SE)描述的森林冠层化学成分浓度的估计精度。由单波段分析的结果说明族叶化学与CASI数据间的相关性很低。事实上 ,对于TP ,CASI原始数据与实验室测定的数据几乎无关 相似文献
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Pablo J Zarco-Tejada John R Miller Gina H Mohammed Thomas L Noland Paul H Sampson 《International Journal of Applied Earth Observation and Geoinformation》2001,3(4):321
This paper reports a series of laboratory and field measurements of spectral reflectance under artificial and natural light conditions which demonstrate that effects of natural chlorophyll fluorescence are observable in the reflectance red edge spectral region. These are results from the progress made to link physiologically-based indicators to optical indices from hyperspectral remote sensing in the Bioindicators of Forest Sustainability Project. This study is carried out on twelve sites of Acer saccharum M. in the Algoma Region, Ontario (Canada), where field measurements, laboratory-simulation experiments, and hyperspectral CASI imagery have been carried out in 1997, 1998, 1999 and 2000 campaigns. Leaf samples from the study sites have been used for reflectance and transmittance measurements with the Li-Cor Model 1800 integrating sphere apparatus coupled to an Ocean Optics Model ST1000 fibre spectrometer in which the same leaves are illuminated alternatively with and without fluorescence-exciting radiation. A study of the diurnal change in leaf reflectance spectra, combined with fluorescence measurements with the PAM-2000 Fluorometer show that the difference spectra are consistent with observed diurnal changes in steady-state fluorescence. Small canopies of Acer saccharum M. have been used for laboratory measurements with the CASI hyperspectral sensor, and under natural light conditions with a fibre spectrometer in diurnal trials, in which the variation of measured reflectance is shown experimentally to be consistent with a fluorescence signature imposed on the inherent leaf reflectance signature. Such reflectance changes due to CF are measurable under natural illumination conditions, although airborne experiments with the CASI hyperspectral sensor produced promising but less convincing results in two diurnal experiments carried out in 1999 and 2000, where small variations of reflectance due to the effect of CF were observed. 相似文献
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笔者在新疆吉木萨尔地区开展航空高光谱遥感油气探测示范研究的过程中,发现油气渗漏地区往往有盐碱化现象。据此,利用航空高光谱成像系统在该区取得的可见光-近红外和短波红外遥感数据,采用自主开发的波段分类填图方法,对吉木萨尔农田、荒地和戈壁地区的油气渗漏异常信息进行了提取,经野外验证和化学分析,圈定了7处油气渗漏异常区。同时,构建了盐碱化的高光谱识别模型,利用该模型进行了盐碱化信息填图,并对吉木萨尔同一覆盖区的盐碱化异常进行了提取,圈定了盐碱化异常区。通过对油气渗漏异常区与盐碱化异常区的叠置聚焦分析,发现二者空间位置有高度的重合性。笔者认为这一高光谱遥感探测发现,不仅具有探索的理论意义,而且具有实用价值。其实用价值主要体现在高光谱遥感油气探测中,通过烃碱信息的相互印证,可以减少油气信息的漏判,提高油气渗漏信息识别的准确性。同时,在缺少航空高光谱遥感数据的情况下,还可以利用卫星多光谱遥感数据源,通过提取盐碱化异常和圈定盐碱化异常区的途径,帮助缩小找油气的目标区,为油气资源的调查、评价和选区提供新的信息和依据。上述研究同时表明,自然界的盐碱化可能并非全是由"干旱蒸发"形成,很可能还存在与油气有关的盐碱化,在油气勘查中如何区分这两种类型的盐碱化,特别是应用高光谱遥感技术将二者区分开来,是值得深入探讨的科学问题。 相似文献
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以高空间分辨率、高光谱分辨率CASI航空遥感数据作为采样带,对黑河中游绿洲灌溉区土地覆盖和农作物种植结构空间格局进行遥感监测。设计了分层分类方法,综合采用基于像素和基于对象的2种遥感图像分类方法对航空样带区域进行土地覆盖制图。根据实地土地覆盖类型调查与目视解译,对样带土地覆盖和农作物种植结构的分类结果进行精度评价,总体分类精度为84.2%,Kappa系数为0.793。与样带区域2007年Landsat TM/ETM+土地覆盖产品相比,高分辨率CASI航空数据能够对树木、草地与农作物类别进行有效监测。监测结果表明,中游绿洲灌溉区内接近59.1%的地区为裸地与建筑用地;植被覆盖区域占39.8%,其中,农田34.9%,树木5.3%,草地仅有0.1%;而在农田区域中玉米为大宗作物,分类成数占96.1%。研究结果表明高质量与高分辨率的航空遥感数据能够实现对流域下垫面异质性进行有效监测,为生态—水文过程研究提供高分辨率的下垫面类型信息。 相似文献
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甘肃龙首山铀成矿带是中国内陆一条重要的铀成矿带。芨岭铀矿床是龙首山成矿带中典型的碱交代型铀矿床,蚀变种类繁多,且与铀矿化关系密切,利用航空高光谱技术可以从宏观上获取芨岭铀矿床地表蚀变、构造、岩性分布信息,为芨岭矿床及周边铀多金属矿产勘查提供依据。本文采用CASI/SASI/TASI航空高光谱遥感技术,对甘肃龙首山地区芨岭碱交代型铀矿区及周围地表出露的热液蚀变进行了研究,识别出了碱性长石、赤铁矿、透闪石、中铝绢云母、高岭石、石英（硅化）等与碱交代热液作用演化密切相关的蚀变矿物,并将蚀变矿物与构造、岩性等要素进行了综合分析。研究表明,碱性长石、透闪石、中铝绢云母和石英（硅化）等蚀变矿物分别代表了芨岭及周围地区碱交代热液作用过程中早期碱交代、中期中性交代、晚期酸性交代等不同演化阶段的热液蚀变作用;芨岭铀矿区碱交代热液作用的主要通道是区域不整合面、深大断裂、不同岩性接触带的复合体,马路沟铀矿控矿断裂的芨岭矿区段明显发育透闪石、中铝绢云母、硅化与碱交代作用相关的热液蚀变。根据芨岭铀矿床的航空高光谱遥感特征,提出了龙首山碱交代型铀矿找矿的主要预测判据。这些判据对龙首山的铀矿找矿新区预测和老矿点、异常点的新评价具有重要的意义。 相似文献