High accuracy NMO correction and application for VTI media     

ZHANG Bo  HAN Liguo  TAN Chenqing  HUANG Fei  HAN Shoufu 《世界地质(英文版)》2012,15(1):78-84

It is difficult for normal moveout(NMO)correction of shallow long offset of vertical transversely isotropic medium,as seismic event after conventional NMO correction experienced strong stretching and distortion due to interleaving of signal.Even using higher order non-hyperbolic NMO correction,it still cannot get the right results.This paper aims to improve the accuracy of NMO correction.Based on the analysis of conventional NMO correction method and previous optimization move-out equation,we use longitudinal optimization method to correct seismic event.The results of the theoretical model and the real data show that our method can completely remove NMO stretching and greatly improve correction accuracy.  相似文献   

An Enhanced Remote Sensing Procedure for Material Mapping in the Western Desert of Egypt: A Tool for Managing Urban Development     

Ahmed Mohamed Youssef 《Natural Resources Research》2008,17(4):215-226

Recently, both the Egyptian government and private sector have been interested in developing low desert zone areas. The low desert zones are located between the recent Nile flood plain and the limestone plateau, from the east and west sides, and represent an important source of aggregate materials. The development of these areas, however, will reduce the supply of aggregate materials so that new sources must be identified. This study describes several processing methods, applied to a Landsat Enhanced Thematic Mapper Plus image of 2001, to develop a reliable method to map the aggregate materials. By using different enhancement techniques with the help of a supervised classification method, it was found that decorrelation stretch and principal component analysis are the most suitable methods to discriminate between different types of aggregates, as well as to isolate these aggregates from the surrounding materials. Field and laboratory investigations indicated that two types of aggregates were recognized, confirming the remote sensing findings.  相似文献   

基坑预应力锚索初始张拉锁定值取值规律探讨     

刘永权  刘新荣  谢应坤  余瑜 《岩土力学》2018,39(6):2164-2174

针对基坑工程中预应力锚索的特点,采用理论推导、算例计算、数值模拟及实例分析的方法,对拉力型、压力型、荷载分散型锚索及锚拉桩上多排预应力锚索的锁定值取值规律进行了探讨。结果表明：由于锚头刚度的差异,拉力型锚索的锁定值宜取规范规定范围的小值,而压力型锚索宜取相应的大值;荷载分散型锚索应分组张拉锁定,各分组钢绞线的锁定值与锚索自由段长度、分散间距及锚头位移有关,且离孔口距离越远,分段承载体锚索锁定值越大;锚拉桩上的多排预应力锚索应考虑锚索的张拉顺序采取不同的锁定值,基于各排锚索张拉锁定后产生的真实锚头位移的差异,上排锚索宜取较小的锁定值,下排锚索宜取较大的锁定值。相关规律可为基坑锚索的张拉锁定施工提供有益的参考。  相似文献   

棉纤维生长各阶段的土壤水分状况对其束强的影响     

郑维 《沙漠与绿洲气象(新疆气象)》2003,26(6):19-21

在纤维伸长前期、填充后期充足的土壤水分对提高束强有利，纤维生长扭曲期土壤干旱对提高束强有利，反之则不利。  相似文献   

若尔盖盆地-西秦岭造山带结合部位深反射资料的静校正和去噪技术   总被引：11，自引：10，他引：1       下载免费PDF全文

王海燕  高锐  马永生  朱铉  李秋生  李朋武  匡朝阳  卢占武 《地球物理学进展》2007,22(3):738-743

深地震反射剖面技术是探测岩石圈精细结构的有效手段.通常情况下工区地质情况复杂,尤其在盆山结合部位,地表地形起伏大,地下构造复杂,其深地震反射资料具有低信噪比、干扰强、构造复杂等特点,给后续处理和解释造成很大困难,因此获得真实的叠加剖面是地质解释的前提和基础.复杂地区低信噪比深地震反射资料处理的关键是做好静校正和去噪工作.本文以若尔盖盆地－西秦岭造山带接合部位深地震反射资料作为例,通过方法试验和参数测试,找到适合该工区的静校正方法和去噪技术,得到较好的处理结果,为揭示若尔盖盆地－西秦岭造山带结合部位的细结构提供了可靠的依据.  相似文献   

辽河盆地新生代多期构造热演化模拟   总被引：20，自引：10，他引：10       下载免费PDF全文

何丽娟 《地球物理学报》1999,42(1):62-68

针对辽河盆地新生代拉张多期性的特点,提出一种适用于多期拉张盆地构造热演化模拟的纯剪切模型．该模型考虑了多期拉张的继承性、横向不均匀性以及拉张速率的可变性。通过几种拉张速率模式的对比,指出拉张速率模式的选择对模拟年轻盆地热演化过程具有重要意义．最后,利用该模型模拟研究了辽河盆地新生代的构造热演化历史．  相似文献   

南海南部礼乐盆地构造热演化研究   总被引：2，自引：1，他引：1  

杨树春  仝志刚  郝建荣  贺清  刘海龄  闫贫 《大地构造与成矿学》2009,33(3)

礼乐盆地位于南海海域南部,是一个形成于中新生代的叠合盆地,长期以来缺乏构造热演化方面研究。本文在认识礼乐盆地构造演化的基础上,选用盆地内地震测线(L2剖面),应用二维横向不均匀拉张模型对礼乐盆地构造热演化史进行了模拟研究。模拟结果揭示了盆地在新生代的构造热演化特征:(1)盆地经历了两次连续的拉张过程,第一期拉张幅度较小,拉张系数在1.05左右,第二次拉张程度较第一次拉张强烈,深水地区拉张系数达到1.3;(2)礼乐盆地两次拉张使得盆地逐步升温,第二次拉张结束时达到历史最高温时期,之后热流持续下降;(3)盆地不同构造部位热流史具有差异性,其中深水区经历的古热流最高,达75mW/m2,礼乐滩最低,仅为63mW/m2。  相似文献   

Tectonic Evolution of the Wanan Basin,Southwestern South China Sea     

Lü Caili  ZHANG Gongcheng  YAO Yongjian  WU Shiguo 《《地质学报》英文版》2014,88(4):1120-1130

Quantitative studies on the extension and subsidence of the Wanan Basin were carried out based on available seismic and borehole data together with regional geological data.Using balanced cross-section and backstripping techniques,we reconstructed the stratigraphic deposition and tectonic evolution histories of the basin.The basin formed from the Eocene and was generally in an extensional/transtensional state except for the Late Miocene local compressoin.The major basin extension ocurred in the Oligocene and Early Miocene(before ~16.3 Ma) and thereafter uniform stretch in a smaller rate.The northern and middle basin extended intensely earlier during 38.6–23.3 Ma,while the southern basin was mainly stretched during 23.3–16.3 Ma.The basin formation and development are related to alternating sinistral to dextral strike-slip motions along the Wanan Fault Zone.The dominant dynamics may be caused by the seafloor spreading of the South China Sea and the its peripheral plate interaction.The basin tectonic evolution is divided into five phases:initial rifting,main rifting,rift-drift transition,structural inversion,and thermal subsidence.  相似文献   

基于曲波稀疏变换的拉伸校正方法     

刘仕友  张明林  宋维琪 《物探与化探》2022,(1)

动校正是地震数据处理中的重要步骤,但它在校正过程中会产生子波拉伸畸变效应,随着偏移距的增大,会出现主频降低、振幅扩大的现象。由于存在拉伸畸变,同相轴未被拉平,导致非同相叠加,会引起水平叠加剖面的频率失真和分辨率下降,因此,拉伸校正是提高水平叠加剖面分辨率的关键。子波拉伸畸变在曲波稀疏域中是不相干的,可以将拉伸校正视为是一个非线性优化过程。通过度量稀疏域中数据的稀疏性,使用一种快速有效的算法,来优化子波拉伸畸变生成的非线性问题,最终实现消除子波拉伸畸变的目的。曲波稀疏变换拉伸校正方法能够消除由动校正带来的子波拉伸畸变,恢复远偏移距处的高频信息,校平同相轴。综合模型数据和实际资料处理,曲波稀疏拉伸校正方法能够显著提高水平叠加剖面的分辨率。  相似文献   

高分辨率遥感影像阴影检测与补偿系统的设计与实现     

杨兴旺  杨树文  张黎明  姚花琴  李轶鲲 《国土资源遥感》2015,(3)

阴影检测与补偿涉及遥感影像的不确定性、算法复杂度高及提取自动化程度低等问题。基于Arc GIS Engine平台,结合Matlab和GDAL开发工具,根据构建的高分辨率遥感影像阴影检测和补偿算法设计了一体化的阴影检测与补偿系统。系统采用了数据分块读取、2%线性拉伸及DLL动态链接库等关键技术,解决了大数据量影像读取、影像不确定性及系统可扩展性等问题,实现了系统的集成和优化,提高了运行效率。测试结果表明,该系统在Quick Bird、资源三号(ZY-3)等高分辨率遥感影像的阴影检测与补偿中具有较高的精度和效率,可用于数据批处理。  相似文献