Detection and imaging of subwavelength features in the subsurface using diffracted waves are rapidly gaining momentum in the oil and gas industry as well as in the fields of engineering, archeology, and homeland security. Most of the methods include coherent summation of the recorded wavefield along diffraction traveltime surfaces from point scatterers. The summation focuses energy onto point-like diffractors that appear at the resulting images as prominent anomalies. However, in cases in which the target is an elongated object such as a fault plane, fracture, tunnel, or elongated cave, a more efficient imaging method can be constructed. We have developed an algorithm for detecting and characterizing linear subsurface elements using a linear-diffractor operator. Our algorithm is based on the coherent summation of the edge diffraction generated by the entire lineament and on the analysis of the calculated coherence measure (semblance). The advantages and limitations of our method are discussed, and the results are compared to conventional point-diffractor-based techniques. Synthetic and real data examples demonstrate that using a linear-diffractor-based algorithm can dramatically improve the detection of linear objects.

中文翻译：

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使用边缘衍射检测亚表面细纹

在石油和天然气工业以及工程，考古学和国土安全领域，利用衍射波检测和成像地下亚波长特征正在迅速获得发展势头。大多数方法都包括沿点散射体沿衍射传播时间表面记录的波场的相干求和。求和将能量聚焦到点状衍射物上，这些点状衍射物在结果图像上以明显的异常出现。然而，在目标是诸如断层，断裂，隧道或细长洞穴之类的细长物体的情况下，可以构造更有效的成像方法。我们已经开发了一种使用线性衍射算子检测和表征线性地下元素的算法。我们的算法基于整个线条产生的边缘衍射的相干总和，以及对计算出的相干度量（相似性）的分析。讨论了我们方法的优点和局限性，并将结果与​​传统的基于点衍射器的技术进行了比较。合成和真实数据示例表明，使用基于线性衍射器的算法可以显着改善线性对象的检测。