Interpreting complex, three-dimensional, near-surface GPR surveys: an integrated modelling and inversion approach
Interpreting complex, three-dimensional, near-surface GPR surveys: an integrated modelling and inversion approach
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DOI：
10.3997/1873-0604.2010010
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发表时间：
2011-06
影响因子：
1.6
通讯作者：
T. M. Millington;N. Cassidy;L. Nuzzo;L. Crocco;F. Soldovieri;J. Pringle
中科院分区：
文献类型：
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作者：
T. M. Millington;N. Cassidy;L. Nuzzo;L. Crocco;F. Soldovieri;J. Pringle
随着现代个人计算机计算能力的不断增强，复杂的建模和反演技术正在成为高分辨率、全三维探地雷达调查解释的流行工具。在本文中，我们介绍了正在进行的用于近地表三维GPR数据解释和分析的新颖、集成、有限差分时域（FDTD）数值模拟和线性层析反演方法的最新实际研究成果。该方法利用Born近似解的反散射问题和截断奇异值分解（TSVD）来创建最终的反向重建。采用三维、全场、O（2,4）精度的时域有限差分建模方案生成基于数值的格林函数和入射场进行反演。因此，精确的天线源（包括屏蔽的影响）和近场空气/地面界面效应固有地包含在反演公式中。该集成方法的性能通过一个模拟的、3D的、基于法医的测试用例（对一个秘密的人类埋葬目标进行900 MHz的调查）来评估，其中包括来自近地表杂波的相干噪声。虽然算例过于简单，但结果表明，尽管在反演方法中存在一些假设，该方案仍能很好地工作。这样，就可以获得有关埋藏特征的真实形式、深度、位置和空间相互关系的有用信息，从而可以在三维环境中获得改进的解释。
With the increasing computational power of modern personal computers, sophisticated modelling and inversion techniques are becoming popular tools for the interpretation of high-resolution, fully three-dimensional GPR surveys. In this paper, we present the latest results of ongoing practical research into the development of novel, integrated, finite-difference time-domain (FDTD) numerical modelling and linear tomographic inversion methods for the interpretation and analysis of near–surface, 3D GPR data. The proposed approach utilizes the Born approximation solution to the inverse-scattering problem and a truncated singular value decomposition (TSVD) to create the final, inverted reconstructions. A three-dimensional, full-field, O(2,4) accurate FDTD modelling scheme is used to generate the numerical-based Green’s functions and incident fields for the inversion. As such, accurate antenna sources (including the influence of shields) and near-field air/ground interface effects are inherently included in the inversion formulation. The performance of this integrated method is evaluated via a simulated, 3D, forensic-based, test-case example (a 900 MHz survey over a clandestine human burial target) including coherent noise from near-surface clutter. Although the example is simplistic, the results show that the scheme works well, despite some assumptions in the inversion methodology. As such, useful information can be gained on the true form, depth, location and spatial interrelationships of the buried features and, therefore, improved interpretations can be obtained in a three-dimensional context.