基于遥感蚀变信息提取巴林格撞击坑周边铁陨石

目前地球上已经得到确认的撞击坑有190余个，其中直径小于1 km的简单撞击坑绝大部分是由铁质撞击体撞击形成的。由铁质撞击体撞击而成的撞击坑周边存在大量的铁陨石物质，这些铁陨石物质的空间分布特征对研究撞击坑的撞击过程和机理具有重要意义。铁元素的异常富集也可作为探寻地球表面疑似撞击坑的重要信息。为了获取撞击坑周围的铁陨石残片，早期主要通过人工方式进行实地调查，但这种方法效率低下且需要投入大量人力物力。基于铁陨石独特的光谱特征，利用遥感蚀变信息提取手段可以很方便地获取撞击坑周边的铁陨石物质。根据铁陨石矿物的波谱特征，以美国亚利桑那州巴林格撞击坑（Barringer Meteor Crater）为研究对象，基于Landsat 8 OLI数据，采用目前提取蚀变信息的常用方法:波段比值（BandMath）—主成分分析法进行撞击坑周边铁陨石信息的提取。提取结果与前人实地调查获取的铁陨石分布情况契合程度较好。撞击坑东侧、东南侧、西南侧等处的铁陨石聚集区在提取结果图上均有较好的反映。表明利用波段比值-主成分分析方法提取巴林格撞击坑周边铁陨石信息是可行的，实验结果准确地获得了该撞击坑周围的铁陨石空间分布信息，为探寻地球表面撞击成因的环形构造提供了可行方案，同时为未来同类撞击坑信息提取提供了重要的方法参考。 

Extraction of iron meteorites from the Barringer Meteor Crater based on remote sensing alteration information

At present, there are more than 190 craters have been confirmed on the earth, and most of the simple impact craters with a diameter of less than 1 km are formed by iron impactor.There is a large amount of iron meteorite material around the impact crater struck by the iron impactor.The spatial distribution characteristics of iron meteorite are of great significance for studying the impact process and mechanism of the crater.The enrichment of iron can also be used as important information to explore suspected impact craters on the Earth's surface.In order to obtain iron meteorite fragments around the impact crater, field investigations were mainly conducted manually in the early days, but this method was inefficient and required a lot of manpower and material resources.Based on the unique spectral characteristics of the meteorite, the spatial distribution characteristics of the meteorite material around the impact crater can be easily obtained by using the remote sensing alteration information extraction method.This paper selects Barringer Meteor Crater in Arizona, USA as the research object, considering of the spectral characteristics of iron meteorite, and using Band Math-PCA(principal components analysis).The extraction results fit well with the field survey of the distribution of iron meteorites by the predecessors.The iron meteorite aggregation area on the east, southeast and southwest sides of the impact crater was well reflected in the extraction results.The iron meteorite around the impact crater was well extracted, and the iron meteorite gathering areas on the east, southeast and southwest sides were well reflected on the extraction result map.It shows that it is feasible to use the principal component analysis-band ratio method to extract the iron meteorite information around the Barringer crater.The experimental results accurately obtained the spatial distribution information of iron meteorite around the impact crater.This paper provides a feasible plan for exploring the ring structure of the impact on the earth's surface, and provides an important method reference for the extraction of similar impact craters in the future.