影像空间分辨率对蚀变信息提取结果的影响研究  

Influence of the Different Spatial Resolutions for Alteration Mineral Mapping

作　　者：刘磊 吴朦朦 尹翠景 周军[1,2] 谢文杨 尹春涛 Liu Lei;Wu Mengmeng;Yin Cuijing;Zhou Jun;Xie Wenyang;Yin Chuntao(Key Laboratory for the study of Focused Magmatism and Giant Ore Deposits,MNR,School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China;Xi’an Spacetime Geo-mineral Technology Limited,Xi'an 710068,China)

机构地区：[1]长安大学地球科学与资源学院,自然资源部岩浆作用成矿与找矿重点实验室,陕西西安710054 [2]西安时空地质矿产技术有限公司,陕西西安710068

出　　处：《遥感技术与应用》2019年第5期1040-1047,共8页Remote Sensing Technology and Application

基　　金：陕西省自然科学基金项目(2018KJXX-062);中央高校基本科研业务费专项资金(310827172006、300102278303)

摘　　要：脉状蚀变分布广泛且蚀变规模一般较小,遥感影像空间分辨率对此类蚀变提取影响严重。为了评估不同空间分辨率数据对脉状矿化蚀变信息的提取能力,以甘肃北山金滩子地区为例,应用航空高光谱CASI/SASI数据,将像元重采样至5、10、15、20和30 m共5种空间分辨率模式;以JPL光谱库中白云母矿物光谱曲线为参考,利用光谱匹配滤波法提取区内白云母化蚀变。不同规模蚀变带在5种分辨率模式下像元光谱表明:面状蚀变由于面积较大,空间分辨率变化对像元光谱吸收特征影响较小;脉状蚀变带特别是较窄脉状蚀变带随着空间分辨率的降低,混合像元影响越来越强,像元光谱的吸收特征越来越浅,30 m空间分辨率时吸收特征最弱。5种空间分辨率影像的白云母矿物提取结果表明较窄蚀变带(宽约1~5 m)在5~15 m空间分辨率图像中均线状特征明显,在20 m分辨率数据结果中仅断续出现,在30 m空间分辨率结果中仅个别像元被突出。Vein-type alterations are extensively distributed and normally very thin,the extraction of these alteration zones is affected by the spatial resolution of remote sensing data seriously. To evaluate the ability of different spatial resolutions for alteration mineral mapping,taking Jintanzi area as the study area,the pixel of airborne CASI/SASI hyperspectral data were resampled to 5 m,10 m,15 m,20 m and 30 m. The spectrum of muscovite from JPL spectral library and matched filtering method were utilized to extract the distribution of muscovite minerals. Spectra of pixels show that for alteration of large areas the spectral features are influenced weakly by the changing of spatial resolution and all the absorption features could be retained. Comparably,for the thin vein-type alteration,with the degradation of spatial resolution,the effect of the mixed pixel is more serious.Thus,the absorption feature of image spectra is very shallow. When the spatial resolution is 30 m,the absorption is weakest and difficult to be identified. The mapping results of the muscovite show that the thin vein-type alteration(about 1 to 5 meters wide)could be identified in the images with resolution of 5 m,10 m and 15 m,while it is difficult for the images with resolution of 20 m and 30 m to detect.

关 键 词：空间分辨率 脉状蚀变 面状蚀变 金滩子地区 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]