南方海相地震资料脊波非线性阈值去噪方法   总被引：2，自引：0，他引：2  

张恒磊  宋双  刘天佑 《应用地球物理》2007,4(4):271-275

小波分析方法在数据处理中已得到成功广泛的应用,这主要得益于它的局部时频分析能力,但是小波分析对方向的表征能力有限。脊波变换具备优越的方向选择性能,能更好地处理含有线状变化特征的信号。本文针对低信噪比地震记录,尝试研究利用脊波变换方法对其进行处理,提高剖面资料信噪比,突出同相轴信息。在对南方某油田的实际地震资料的处理中,可以发现处理后的地震剖面同相轴品质及连续性有了明显改善,信噪比增强,分辨率相应提高,体现出了该方法相对常规小波分析方法的优越性。  相似文献   

Characteristics and method of synthesis seismic wave based on wavelet reconstruction     

邹立华  刘爱平杨宏 柴新建尚歆  戴素亮董博 《地震学报(英文版)》2007,20(6):675-683

A novel method of synthesizing seismic wave using wavelet reconstruction is proposed and compared with the traditional method of using theory of Fourier transform. By adjusting the frequency band energy and taking it as criterion, the formula of synthesizing seismic wave is deduced. Using the design parameters specified in Chinese Seismic Design Code for buildings, seismic waves are synthesized. Moreover, the method of selecting wavelet bases in synthesizing seismic wave and the influence of the damping ratio on synthesizing results are analyzed. The results show that the synthesis seismic waves using wavelet bases can represent the characteristics of the seismic wave as well as the ground characteristic period, and have good time-frequency non-stationary.  相似文献   

Archaeomagnetic secular variation in the UK during the past 4000 years and its application to archaeomagnetic dating     

I. Zananiri  C.M. Batt  D.H. Tarling 《Physics of the Earth and Planetary Interiors》2007,160(2):97-107

This paper examines the limitations and deficiencies of the current British archaeomagnetic calibration curve and applies several mathematical approaches in an attempt to produce an improved secular variation curve for the UK for use in archaeomagnetic dating. The dataset compiled is the most complete available in the UK, incorporating published results, PhD theses and unpublished laboratory reports. It comprises 620 archaeomagnetic (directional) data and 238 direct observations of the geomagnetic field, and includes all relevant information available about the site, the archaeomagnetic direction and the archaeological age. A thorough examination of the data was performed to assess their quality and reliability. Various techniques were employed in order to use the data to construct a secular variation (SV) record: moving window with averaging and median, as well as Bayesian statistical modelling. The SV reference curve obtained for the past 4000 years is very similar to that from France, most differences occurring during the early medieval period (or Dark Ages). Two examples of dating of archaeological structures, medieval and pre-Roman, are presented based on the new SV curve for the UK and the implications for archaeomagnetic dating are discussed.  相似文献   

A Least-squares Window Curves Method for Interpretation of Magnetic Anomalies Caused by Dipping Dikes   总被引：1，自引：0，他引：1  

E. M. Abdelrahman  E. R. Abo-Ezz  K. S. Soliman  T. M. El-Araby  K. S. Essa 《Pure and Applied Geophysics》2007,164(5):1027-1044

We have developed a least-squares method to determine simultaneously the depth and the width of a buried thick dipping dike from residualized magnetic data using filters of successive window lengths. The method involves using a relationship between the depth and the half-width of the source and a combination of windowed observations. The relationship represents a family of curves (window curves). For a fixed window length, the depth is determined for each half-width value by solving one nonlinear equation of the form f (z) = 0 using the least-squares method. The computed depths are plotted against the width values representing a continuous curve. The solution for the depth and the width of the buried dike is read at the common intersection of the window curves. The method involves using a dike model convolved with the same moving average filter as applied to the observed data. As a result, this method can be applied to residuals as well as to measured magnetic data. Procedures are also formulated to estimate the amplitude coefficient and the index parameter. The method is applied to theoretical data with and without random errors. The validity of the method is tested on airborne magnetic data from Canada and on a vertical component magnetic anomaly from Turkey. In all cases examined, the model parameters obtained are in good agreement with the actual ones and with those given in the published literature.  相似文献   

ROI技术在车牌识别系统中图像存储方面的应用研究   总被引：1，自引：0，他引：1  

刘海林  李灿平  王绪本 《物探化探计算技术》2002,24(4):362-366

ROI（region of interest，感兴趣区域）作为新一代图像压缩标准JPEG2000所增加的一个功能。利用该功能，我们能够针对图像内容进行不同级别压缩，从而提高图像的压缩比，在目前的车牌识别系统中，由于车牌识别精度不高，以及为了更好地查证车辆等原因，仍需存储图像数据，并且，为了减少图像的数据量，还需要对图像进行压缩处理，由于我们对车牌图像中的不同内容，精度要求不同，因此，可以利用ROI方法进行图像压缩，从而减少图像的数据量。  相似文献   

煤田三维地震资料解释的时深转换方法研究   总被引：2，自引：0，他引：2  

龚幸林  林建东 《中国煤田地质》2002,14(2):65-67

时深转换是三维地震资料解释中提高勘探精度非常关键的一步。本文介绍了三种不同的时深转换方法及时深转换速度的求取,并分别用实例加以说明,阐述了如何根据不同的地质及地震地质条件,选择合适的时深转换方法,以达到最佳的勘探效果。  相似文献   

水溶性污染物在土壤中转化的原位实验方法   总被引：3，自引：0，他引：3  

杨胜科  王文科  李翔  李永涛  姜桂华 《西北地质》2002,35(2):20-23

建立了一种研究水溶性污染物在土壤中运转化的原位实验方法，该方法已成功地应用于研究黄土中氨氮的运移转化规律，克服了土柱实验存在的破坏土壤结构及氧化还原电位发生变化等所引起的实验误差。  相似文献   

基于分类K—L变换的多波段遥感图像近无损压缩方法   总被引：4，自引：0，他引：4  

倪林 《遥感学报》2001,5(3):205-213

去除空间和谱间相关性是多波段遥感图像压缩中的重要环节，为了得到更好的去相关效果，将矢量量化方法引入多波段遥感图像压缩中，以去除对应同一地物的波段矢量间的相关性，再通过分类K－L变换去除量化误差图像的变间相关性，对K－L变换后的特征图像采用预测树的方法进一步去除谱间结构相关性和空间相关性，实验结果表明，该方法可以取得很好的压缩效果。  相似文献   

基于空间统计学的空间数据窗口大小的确定   总被引：12，自引：3，他引：12  

马洪超  李德仁 《武汉大学学报(信息科学版)》2001,26(1):18-23

提出基于空间统计学的方法来确定空间数据窗口大小,实例证明是可行的。同时提出了对海底照片成像不均匀光照进行纠正的思路和方法，该方法简单有效，效果较理想。  相似文献   

基于整数小波变换的多光谱图像无损压缩   总被引：9，自引：0，他引：9  

张荣  俞能海  刘政凯  吴文忠 《遥感学报》2001,5(1):29-33

多光谱图像一般都采用预测方法去除空间冗余和谱内冗余实现无损压缩。通过用提升方法构造整数小波变换, 将变换方法用于去除空间冗余；通过分类方法构造谱间预测器，用预测方法去除谱间冗余，两者相结合，实现无损压缩。由于变换方法的去相关性能良好，使该方法压缩效果大大改善。  相似文献