摘要
在Gabor域描述散射体,且入射波场为短时宽带信号时,扰动波场可以在频率域用高斯束或在时间域用高斯波包描述。在此基础上,提出一种散射体成像方法,该方法对数据进行特征高斯波包分解,分解出的高斯波包独立反传,反传的高斯波包反投影到模型域得到一个Gabor函数描述的散射体(简称Gabor散射体)。将所有Gabor散射体叠加可以得到最终的成像结果。高斯波包散射体成像结果具有模型域的量纲,计算量较小且应用灵活。数值实验表明,本文提出的散射体成像方法精度较高,成像策略和流程适用于一般散射体。
When perturbed model is described with Gabor frames, the scatter waves can be calculated with Gaussian beam in the frequency domain or Gaussian packet in the time domain. For this case the precondition is that signals of the incident background wave-field should be short-duration in the time domain and broad-band in the frequency domain. With the above-mentioned modeling method an effective scatterer imaging algorithm is put forward. A common-shot-gather is decomposed with characteristic Gaussian packet firstly. All of the Gaussian packets that describe the common-shot-gather are back-propagated and projected into the model domain independently. The final scatterer is obtained by integrating all of the Gabor-scatterers that projected from Gaussian packets. One of the scatterer imaging method's key points is how to project Gaussian packet into the model domain. The scatterer imaging method is composed by 3 parts of the imaging algorithm, the projection theory from a Gaussian packet to a Gabor-scatterer, and the back-propagation scheme of Gaussian packet. The proposed scatterer imaging method gives the image that has the dimension in the model domain. Gaussian packet shares higher efficiency and better flexibility compared with wave equation. The accuracy of the proposed scatterer inversion method is tested and analyzed with a single Gabor-scatterer model in the numerical experiment. The scatterer inversion scheme is also applied in synthetic models and promising results is presented. Both of the experiments show that the proposed method shares high efficiency, and the algorithm is suitable for general models. © 2017, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2017年第2期273-282,共10页
Oil Geophysical Prospecting
基金
国家重大专项(2016ZX05024001-006和2016ZX05026001-003)
国家自然科学基金面上项目(41274117)联合资助
关键词
高斯波包
扰动波场
散射体
成像
GABOR函数
Backpropagation
Backpropagation algorithms
Efficiency
Frequency domain analysis
Gaussian beams
Gaussian distribution
Imaging techniques
Numerical methods
Time domain analysis
