Radiometric normalization of overlapping LiDAR intensity data for reduction of striping noise     

Wai Yeung Yan  Ahmed Shaker 《International Journal of Digital Earth》2016,9(7):649-661

Airborne LiDAR data are usually collected with partially overlapping strips in order to serve a seamless and fine resolution mapping purpose. One of the factors limiting the use of intensity data is the presence of striping noise found in the overlapping region. Though recent researches have proposed physical and empirical approaches for intensity data correction, the effect of striping noise has not yet been resolved. This paper presents a radiometric normalization technique to normalize the intensity data from one data strip to another one with partial overlap. The normalization technique is built based on a second-order polynomial function fitted on the joint histogram plot, which is generated with a set of pairwise closest data points identified within the overlapping region. The proposed method was tested with two individual LiDAR datasets collected by Teledyne Optech's Gemini (1064?nm) and Orion (1550?nm) sensors. The experimental results showed that radiometric correction and normalization can significantly reduce the striping noise found in the overlapping LiDAR intensity data and improve its capability in land cover classification. The coefficient of variation of five selected land cover features was reduced by 19–65%, where a 9–18% accuracy improvement was achieved in different classification scenarios. With the proven capability of the proposed method, both radiometric correction and normalization should be applied as a pre-processing step before performing any surface classification and object recognition.  相似文献   

Evaluation of Two Absolute Radiometric Normalization Algorithms for Pre-processing of Landsat Imagery   总被引：5，自引：0，他引：5  

徐涵秋 《中国地质大学学报(英文版)》2006,17(2):146-150,157

INTRODUCTIONMultitemporal satellite i magery has long beeninvolvedin the detection of changes occurringin nat-ural ecosystems . The accuracy of the result largelyrelies onthe consistency of at mospheric andillumina-tion conditions of the multitemporal i mages used.However ,the date and seasonal variations resultingin different at mospheric and illumination effects usu-ally cause errors in change detection results . Accord-ingly ,pre-processing of multitemporal i magery usingabsolute or re…  相似文献   

 卫星影像的云雾检测及干扰去除     

徐逸祥  朱子豪  刘英毓 《国土资源遥感》2006,17(3):23-28

云雾检测及去除是光学遥感图像处理的难题。厚云雾因具高反射特性，可通过阈值的设定将其检测并去除； 薄云因混有地物 光谱特性而较难检测，需先对影像做相对辐射校正处理，再将影像由RGB转换成HIS彩色模型，并假设薄云雾的加入等于白色颜料的加 入，即仅改变光谱的亮度或饱和度值，色相并无改变，藉此，可用多时段方式检测。实践证明，在HIS系统中可简化薄云雾的检测准 则，大大提高自动化检测云雾的可能性。  相似文献   

常用围岩分类方法对某深埋隧洞的适用性分析   总被引：3，自引：0，他引：3  

葛华  王广德  石豫川  寇佳伟  单治钢  周春宏 《中国地质灾害与防治学报》2006,17(2):44-49

某深埋隧洞局部地应力高达42 MPa,局部外水压力高达10 MPa,具有高地应力、高外水压力的特点。一般认为,最大主应力大于20 MPa属于高地应力,外水压力远大于1 MPa为高外水压力。采用Q系统、RMR分类、水电规范HC分类、国标BQ分类等4种常用围岩分类方法对该隧洞进行了围岩分类。分类结果表明,高地应力条件下,Q系统的适用性较好,RMR分类、HC分类、BQ分类适用性均差。4种分类方法在高外水压力条件下的适用性均差。出现上述现象的主要原因有:Q系统通过最大切向应力与岩石抗压强度的比值σθ/σc的大小,反映高地应力对围岩类别的影响。故其在高地应力条件下的适用性较好;RMR分类没有考虑高地应力对围岩类别的影响。其分类结果在高地应力区特别是岩爆段偏高;HC分类在高地应力区简单地采用降级的方法。其分类结果误差较大;BQ分类对岩石强度过于敏感。其分类结果在高地应力区过于保守。这4种方法均未考虑高外水压力对围岩类别的影响。论文提出了一种“归一化方法”,可以对不同分类方法分类结果进行相互比较。  相似文献   

钍归一化法在松辽盆地开鲁坳陷大林地区地面伽马能谱资料处理中的应用研究     

黄笑  余弘龙  江丽  王殿学  周文博  马振宇  张亮亮  唐国龙 《物探与化探》2021,(2):316-322

在可地浸砂岩型铀矿勘查中,地面伽马能谱测量因地表覆盖层等的影响,有效信息往往被掩盖。为有效提取铀矿化信息,对在松辽盆地开鲁坳陷大林铀矿产区采集的地面伽马能谱数据开展钍归一化法处理。获得的铀剩差异常范围与区内铀矿体及断裂的空间展布相吻合。经分析表明,钍归一化法能够有效反映断裂的存在。该区断裂对铀成矿控制明显,区内铀剩差异常区为氧化还原过渡带,可为该区下一步找矿工作提供依据。  相似文献   

湖南锡矿山超大型锑矿床围岩蚀变元素迁移特征及定量计算研究     

弭希风  胡瑞忠  付山岭  彭建堂  骆金诚  陈应华 《矿物岩石地球化学通报》2019,(1):103-113

湖南锡矿山锑矿床是目前世界上已发现的最大的锑矿床,其硅化非常发育且与矿化关系密切,根据硅化蚀变程度的强弱,从围岩到矿石大致划分为4个带:灰岩→弱硅化灰岩→强硅化灰岩→矿石。为揭示锡矿山锑矿的成矿过程及成矿流体信息,利用Isocon标准化方法,以Al_2O_3为惰性组分,对各蚀变带围岩及矿石的主、微量元素进行质量平衡计算。结果表明,热液蚀变过程中,Si、Sb、Li和Bi等大量迁入,而Ca、Mg、Na和大离子亲石元素Sr、Ba、Rb等大量迁出;成矿热液呈酸性并富硅,其中Hg、As、Au、Tl等元素含量极低,这可能是导致锡矿山锑矿床矿种单一的原因之一。稀土元素除Eu外,其他元素未发生明显的活化迁移,水岩反应并未影响原岩的稀土元素配分模式;蚀变岩及矿石中的Eu负异常可能表明成矿过程是在相对还原的环境下进行的。  相似文献   

赣南地区P波、S波随频率衰减关系研究     

汤兰荣  董非非  曾新福  项月文 《地震研究》2015,38(1)

利用发生在赣南地区的183次ML≥1.0地震资料,采用尾波归一化方法对寻乌、安远和龙南3个台站的P波、S波品质因子QP和QS值进行了计算,分析了该地区地壳介质的衰减特征。研究结果表明,寻乌(流逝时间35 s)和龙南台(流逝时间40 s)QP值较可靠且值相近,拟合平均值为QP(f)=(20.76+1.67)*f(1.03±0.04),寻乌台和安远台(流逝时间均为21 s)拟合平均值为QS(f)=(18.86+1.46)*f(0.84±0.04)。Q值总体呈现低Q0和高η值的特点,这是构造运动活跃地区的特征体现,也和该地区中强地震比较活跃的特征相符。  相似文献   

光谱角—欧氏距离的高光谱图像辐射归一化     

孙艳丽  张霞  帅通  尚坤  冯淑娜 《遥感学报》2015,19(4):618-626

辐射归一化旨在减小不同时相遥感影像间因获取条件不一致而导致的非地表辐射变化的差异,是土地覆盖变化监测的重要前提条件。本文根据高光谱图像上同类地物的谱形及数值的相似性,利用光谱角距离(SAD)和欧氏距离(ED)双重判定选取不变特征点,提出了一种基于光谱角—欧氏距离的辐射归一化方法。在评价指标中除了常用的均方根误差和相对偏差,更增加了高光谱特色的衡量光谱保真性指标:皮尔森系数、光谱扭曲程度。利用高光谱遥感CHRIS图像对本文提出方法进行验证,并与基于多元变化检测(MAD)的辐射归一化方法比较。结果表明,本文方法不仅在辐射特性上优于基于多元变化检测(MAD)的方法,而且具有保持光谱特性的优势,具有较好的应用前景。  相似文献   

Structural identification with incomplete output‐only data and independence of measured information for shear‐type systems          下载免费PDF全文

Suparno Mukhopadhyay  Hilmi Luş  Raimondo Betti 《地震工程与结构动力学》2016,45(2):273-296

Structural identification is the inverse problem of estimating physical parameters of a structural system from its vibration response measurements. Incomplete instrumentation and ambient vibration testing generally result in incomplete and arbitrarily normalized measured modal information, often leading to an ill‐conditioned inverse problem and non‐unique identification results. The identifiability of any parameter set of interest depends on the amount of independent available information. In this paper, we consider the identifiability of the mass and stiffness parameters of shear‐type systems in output‐only situations with incomplete instrumentation. A mode shape expansion‐cum‐mass normalization approach is presented to obtain the complete mass normalized mode shape matrix, starting from the incomplete non‐normalized modes identified using any operational modal analysis technique. An analysis is presented to determine the minimum independent information carried by any given sensor set‐up. This is used to determine the minimum necessary number and location of sensors from the point of view of minimum necessary information for identification. The different theoretical discussions are illustrated using numerical simulations and shake table experiments. It is shown that the proposed identification algorithm is able to obtain reliably accurate physical parameter estimates under the constraints of minimal instrumentation, minimal a priori information, and unmeasured input. The sensor placement rules can be used in experiment design to determine the necessary number and location of sensors on the monitored system. John Wiley & Sons, Ltd.  相似文献   

复合类别支持的多元线性回归遥感影像色彩归一化方法     

吴炜  程熙  顾国民 《地球信息科学学报》2016,18(5):615-621

受植被时相变化、传感器畸变、获取时刻大气条件等因素的影响,不同时间获取的遥感影像存在色彩差异,而逐波段的色彩归一化容易引起新的色彩畸变。因此,本文提出一种复合类别支持的多元线性回归遥感影像色彩归一化方法,在输入影像和参考影像逐波段高斯归一化的基础上,进行复合聚类,确定各像元的复合类别;在迭代去除变化像元的基础上,将类别中心作为控制点,建立多元线性回归方程,并据此对输入影像进行处理。2组影像的试验结果表明,本文方法相对于传统方法在整体精度、色彩保持等方面具有较大的优势。  相似文献