Joint inversion of full-waveform ground-penetrating radar and electrical resistivity data: Part 1
Joint inversion of full-waveform ground-penetrating radar and electrical resistivity data: Part 1
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DOI：
10.1190/geo2019-0754.1
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发表时间：
2020-11
期刊：
影响因子：
3.3
通讯作者：
D. Domenzain;J. Bradford;J. Mead
中科院分区：
文献类型：
--
作者：
D. Domenzain;J. Bradford;J. Mead
我们开发了一种全波形探地雷达（GPR）和电阻率（ER）数据联合反演的算法。探地雷达数据通过反射率和速度对介电常数敏感，通过反射率和衰减对电导率敏感。 ER 数据对电导率直接敏感。这两类数据通过麦克斯韦方程有着内在的联系，我们共同对它们进行反演。我们的结果表明，两种类型的数据协同工作，可以有效地相互规范，同时尊重地球物理方法的物理原理。我们首先使用伴随方法分别计算 GPR 和 ER 数据的灵敏度更新，然后对这些更新求和以考虑两种类型的灵敏度。敏感性是通过让两种数据类型始终对我们的反演做出贡献的范例来添加的，其贡献与它们各自的目标函数在每次迭代中的解决程度成比例。我们的算法没有假设地下几何形状，也没有假设参数之间的结构相似性，但需要一个良好的初始模型。我们发现我们的联合反演优于 GPR 和 ER 单独反演，并且我们确定 GPR 在低电导率区域有效支持 ER，而 ER 在强衰减区域支持 GPR。
We have developed an algorithm for joint inversion of full-waveform ground-penetrating radar (GPR) and electrical resistivity (ER) data. The GPR data are sensitive to electrical permittivity through reflectivity and velocity, and electrical conductivity through reflectivity and attenuation. The ER data are directly sensitive to the electrical conductivity. The two types of data are inherently linked through Maxwell’s equations, and we jointly invert them. Our results show that the two types of data work cooperatively to effectively regularize each other while honoring the physics of the geophysical methods. We first compute sensitivity updates separately for the GPR and ER data using the adjoint method, and then we sum these updates to account for both types of sensitivities. The sensitivities are added with the paradigm of letting both data types always contribute to our inversion in proportion to how well their respective objective functions are being resolved in each iteration. Our algorithm makes no assumptions of the subsurface geometry nor the structural similarities between the parameters with the caveat of needing a good initial model. We find that our joint inversion outperforms the GPR and ER separate inversions, and we determine that GPR effectively supports ER in regions of low conductivity, whereas ER supports GPR in regions with strong attenuation.