子波估计及极大似然反褶积方法稳健性讨论     

刘洪林  胡建  王金山  朱秋影 《物探化探计算技术》2004,26(1):9-12

利用极大似然反褶积提取鲁棒性地震子波的方法进行了研究，并讨论了极大似然反褶积的稳健性。理论分析表明，在理想条件下极大似然反褶积是无偏估计，而且还是一致估计，这一结论可以由所提取的地震子波得到验证。实际地震资料的处理结果分析表明，极大似然反褶积具有很好的稳健性。应当指出，为保证地震子波的鲁棒性，极大似然反褶积子渡时窗应尽量满足统计条件，以提高极大似然反褶积的稳健性。  相似文献   

Isolation of atmospheric effects on rapid polar motion through Wiener filtering     

Susan M. di Leonardo  S. R. Dickman 《Geophysical Journal International》2004,159(3):863-873

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利用欧拉反褶积法估计二度磁性体深度与位置   总被引：7，自引：0，他引：7  

史辉  刘天佑 《物探与化探》2005,29(3):230-233

为了利用欧拉反褶积进行快速计算,提出了多个大小不同的滑动窗口进行多次覆盖的算法,对高精度磁测剖面逐点反复计算,并根据统计学原理从大量计算结果中剔除坏解,保留合理的解;还根据2-D模型讨论了结构指数与欧拉反褶积的结果的关系。将该方法应用于我国西北某地区的高精度航磁资料处理,获得较好的地质效果。  相似文献   

Extraction of near-surface properties for a lossy layered medium using the propagator matrix     

K. Mehta  R. Snieder  V. Graizer 《Geophysical Journal International》2007,169(1):271-280

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大民屯凹陷高分辨地震资料处理技术研究     

赵延江  段云卿  杨文军  高海燕  皮金云 《物探与化探》2007,31(4):370-373

通过对大民屯凹陷地震资料的详细分析，针对洼陷部位信噪比高、主要目的层沙三、沙四段频率相对较低的特点，研究出一套高分辨率处理技术，主要包括子波处理技术及优势频带约束下的分频处理技术，能满足沙三、沙四段储层横向预测的需要，见到了较好的应用效果。  相似文献   

Investigation of Crustal Thickness in Eastern Anatolia Using Gravity,Magnetic and Topographic Data     

Oya Ankaya Pamukçu  Zafer Akçığ  Şevket Demirbaş  Ekrem Zor 《Pure and Applied Geophysics》2007,164(11):2345-2358

The tectonic regime of Eastern Anatolia is determined by the Arabia-Eurasia continent-continent collision. Several dynamic models have been proposed to characterize the collision zone and its geodynamic structure. In this study, change in crustal thickness has been investigated using gravity, magnetic and topographic data of the region. In the first stage, two-dimensional low-pass filter and upward analytical continuation techniques were applied to the Bouguer gravity data of the region to investigate the behavior of the regional gravity anomalies. Next the moving window power spectrum method was used, and changes in the probable structural depths from 38 to 52 km were determined. The changes in crustal thickness where free air gravity and magnetic data have inversely correlated and the type of the anomaly resources were investigated applying the Euler deconvolution method to Bouguer gravity data. The obtained depth values are consistent with the results obtained using the power spectrum method. It was determined that the types of anomaly resources are different in the west and east of the 40° E longitude. Finally, using the obtained findings from this study and seismic velocity models proposed for this region by previous studies, a probable two-dimensional crust model was constituted.  相似文献   

Test of the Empirical Green's Function Deconvolution on Vrancea (Romania) Subcrustal Earthquakes     

Popa  Mihaela  Radulian  Mircea 《Studia Geophysica et Geodaetica》2000,44(3):403-429

Vrancea is one of the few singular seismic regions of the world where intermediate-depth earthquakes are permanently generated (around 10 events/month with M _L > 3) within an extremely confined focal volume. This particularity and the relatively large number of short-period waveforms recorded by the Romanian local network provides us the opportunity to test the performance of the empirical Green's function technique in retrieving the source time function and source directivity of the Vrancea earthquakes. Three earthquakes that occurred on March 11, 1983 (M _L = 5.4), April 12, 1983 (M _L = 5.1) and August 7, 1984 (M _L = 5.1) in the lower part of the subducting lithosphere (h 150 km) were analyzed. A set of 28 adjacent events (3.0 < M _L < 4.4) which occurred between 1981 and 1997 were selected as corresponding empirical Green's functions. To test the confidence of the retrieved source time function, we compare the deconvolved pulses using Green's functions of different sizes and recorded simultaneously by short-period and broad-band instruments. Our tests show that the durations of the source time function is well-constrained and is not affected by the limited frequency range of the short-period instruments, or by the relative difference in the focal mechanism between the main event and Green's event. The apparent duration of the source time function outlines source directivity effects, and when these effects are sufficiently strong, they can identify the real fault plane. Relatively short source duration and correspondingly high stress drop values are in agreement with other previous results emphasizing a specific seismic regime in the lower part of the Vrancea subducting lithosphere.  相似文献   

Radiometric correction of hemispherical images     

Andres Kuusk  Markko Paas 《ISPRS Journal of Photogrammetry and Remote Sensing》2007,61(6):405-413

Light scattering in fore-optics of imaging radiometric instruments degrades images, the signal of dark pixels is enhanced and that of bright pixels is reduced. A procedure of restoring hemispherical images obtained with a hemispheric view CCD-radiometer is suggested. The circular hemispheric image is projected onto the sphere and Wiener filtering on the sphere is performed. For building the Wiener filter the point spread function of the instrument was measured in the laboratory, and test images of (partially) controlled radiance were measured. The procedure is applied for the correction of hemispherical radiometric images taken under forest canopy. In non-corrected near infrared images the signal of sky pixels in forest canopy gaps near zenith is enhanced 1.4–2.0 times. The applied correction reduces this error to the level of 1.1–1.2. In the red channel these figures are 0.8–0.9 and 0.97–0.99, respectively.  相似文献   

改进APEX算法在图像增强中的应用     

孙雷  张艳  徐青  张春美 《测绘学院学报》2007,(1)

APEX是一种基于快速傅立叶变换的直接盲解卷积算法,能够快速复原复杂纹理图像。该算法适用于平移不变且以2维放射对称Le’vy Stable概率密度函数(G类点扩散函数)作为卷积核的图像。论述了A-PEX算法的原理,并针对APEX在适应性和稳定性方面的不足提出了改进方法。实验表明,改进的APEX算法能够有效应用在多种真实模糊图像上,增强图像对比度和锐化图像细节,使图像的视觉效果得到明显改善。  相似文献   

基于HMRF先验模型的HBE卫星遥感图像超分辨率重建   总被引：1，自引：0，他引：1  

张艳  王涛  徐青  孙雷 《武汉大学学报(信息科学版)》2007,32(7):589-592

提出了一种在Bayes概率统计框架下的混合Bayes超分辨率重建算法，该算法采用Huber马尔可夫随机场（Huber Markov random field，HMRF）模型对理想图像进行先验建模，可以较好地突出重建图像的不连续边缘特征信息。实验结果表明，该算法克服了极大后验概率估计（maximum a posteriori，MAP）算法中的若干缺陷，取得了良好的重建结果，图像边缘特征清晰，纹理信息突出。  相似文献