2-D ray‐based tomography for velocity, layer shape, and attenuation from GPR data
2-D ray‐based tomography for velocity, layer shape, and attenuation from GPR data
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DOI：
10.1190/1.1444662
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发表时间：
1999-10
期刊：
影响因子：
3.3
通讯作者：
Jun Cai;G. McMechan
中科院分区：
文献类型：
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作者：
Jun Cai;G. McMechan
利用多偏移探地雷达（GPR）反射数据对近地表结构进行层析反演。该模型被参数化为具有恒定速度和恒定衰减的层。该解决方案分为两部分。首先，根据观测到的反射传播时间估计每层的速度和形状；然后使用该几何形状和相应的射线路径，根据观察到的相对振幅来估计每层的衰减。这两个断层摄影问题的求解都是通过灵敏度矩阵的奇异值分解来执行的（以计算信息密度、分辨率和协方差矩阵以及解）。对已知解的合成数据的测试表明，该算法有效地收敛到正确解的邻域。对来自河流/风成环境的探地雷达线路中的多通道现场数据进行反演，生成的模型与所获得的结构图像和速度估计一致。
Tomographic inversion for near‐surface structure from multioffset ground‐penetrating radar (GPR) reflection data is implemented. The model is parameterized as layers with constant velocity and constant attenuation. The solution is divided into two parts. First, the velocity and shape of each layer are estimated from the observed reflection traveltimes; then using this geometry and the corresponding ray paths, the attenuation of each layer is estimated from the observed relative amplitudes. Solution of both tomographic problems is performed by singular value decomposition of the sensitivity matrix (to compute information density, resolution, and covariance matrices as well as the solution). Tests on synthetic data, for which the solution is known, show that the algorithm converges efficiently to the neighborhood of the correct solution. Inversion of multichannel field data in a GPR line from a fluvial/eolian environment produces a model that is consistent with structural images and velocity estimates obtai...