月表撞击坑自动识别与提取的新方法及其应用  

A new automated approach to detecting and extracting lunar craters and its application

作　　者：张锋[1,2] 邹永廖[1] 郑永春[1] 付晓辉[1,2] 

机构地区：[1]中国科学院国家天文台,北京100012 [2]中国科学院研究生院,北京100049

出　　处：《地学前缘》2012年第6期118-127,共10页Earth Science Frontiers

基　　金：国家高技术研究发展计划"863"项目(2009AA122201);国家自然科学基金项目(40904051)

摘　　要：月表撞击坑是月球最显著的地质构造特征。随着不同月球探测器探测数据的丰富与数据质量的提高,月表地质信息挖掘成为月球科学领域重要的研究内容。月表分布广泛的撞击事件的撞击机理研究和月表地质单元的地质年龄的判定等科学问题都离不开对撞击坑的研究。因此,对撞击坑进行识别和特征参数提取是挖掘以上月表地质隐含信息的基础和关键。针对目前用于撞击坑识别和特征参数提取的方法存在效率低下、应用范围有限等种种缺陷,提出了一种新的月表环形构造识别和特征参数提取方法,并且实现了定量自动化处理。首先,根据撞击坑环形构造特征,利用坡度指数提取坑壁多边形矢量要素;其次,提出并采用环形构造最小外包矩形法提取撞击坑的伪中心与伪直径;然后,以伪中心为中心点向外搜寻并确定撞击坑坑缘顶点;最后,利用三点定圆法确定撞击坑的中心位置和直径大小。以嫦娥一号CCD相机影像数据和利用CCD立体相机制作的DEM数据为数据源,选取不同区域、不同类型的月表撞击坑进行试验,并将计算结果与目前研究成果进行对比。结果验证表明,此方法可以推广到月表其他表面,并可应用于月表撞击坑形成机理研究和利用撞击坑大小-频率分布测量的方法确定月表地质单元的地质年龄工作中。Lunar craters stand out visually among the features on the Moon.Craters are among the most studied subjects when it comes to the analysis of the surface of the Moon since they provide us with the relative age of the surface unit and more information on the lunar surface geology.The question of their automatic identification in images has been tackled in several studies.However,the low efficiency and not widely being used are the main common weakness in current most methods.In this paper,a new automated approach to detect and extract lunar craters is proposed,and four steps are used：（1） gradient index is used to obtain polygon vector feature of crater wall on the basis of the characteristics of craters＇ shape and structure,（2） the minimum bounding rectangle method was proposed and adopted to extract pseudo-centers and pseudo-diameters of craters,（3） the work of researching crater rim crest is performed,with the pseudo-center as the search center,and（4） the method to determine a circle based on three points is applied to determine true-centers and true-diameters of craters.In this study,Chang＇e-I＇s CCD image and DEM data obtained from CCD stereo camera are used.We chose some types＇ craters of different regions as the study objects.And the results extracted will be compared with the previous research values.It proved that the method was able to be applied to other areas of the lunar surface and used in the subsequent lunar crater forming mechanism research and geological age determining work based on the crater size-frequency distribution measurement technique.

关 键 词：撞击坑 特征参数 自动提取 嫦娥一号 月球 

分 类 号：P184.5[天文地球—天文学]