论文标题
新颖的机载EM图像评估工具，用于不完美的正向建模
Novel Airborne EM Image Appraisal Tool for Imperfect Forward Modelling
论文作者
论文摘要
全3D倒置时间域空降电磁（AEM）数据需要专家的专业知识和大量的计算资源，所有人都不容易获得。因此，使用更快但近似（1D）的前向模型，准2D/3D反转方法正在盛行。我们提出了一个评估工具，该工具指示反转模型中与多维数据一致的区域，因此不应定量解释。图像评估依赖于多维向前建模来计算所谓的归一化梯度。该梯度中的大值表示模型参数不符合观察到的数据的真实多维性，并且不应定量解释。提出了一种替代方法来说明不完善的正向建模，以使评估工具在计算上是便宜的。该方法在盐化环境中的AEM调查中进行了证明，揭示了估计的新鲜盐水界面中可能的有问题区域。
Full 3D inversion of time-domain Airborne ElectroMagnetic (AEM) data requires specialists' expertise and a tremendous amount of computational resources, not readily available to everyone. Consequently, quasi-2D/3D inversion methods are prevailing, using a much faster but approximate (1D) forward model. We propose an appraisal tool that indicates zones in the inversion model that are not in agreement with the multidimensional data and therefore, should not be interpreted quantitatively. The image appraisal relies on multidimensional forward modelling to compute a so-called normalized gradient. Large values in that gradient indicate model parameters that do not fit the true multidimensionality of the observed data well and should not be interpreted quantitatively. An alternative approach is proposed to account for imperfect forward modelling, such that the appraisal tool is computationally inexpensive. The method is demonstrated on an AEM survey in a salinization context, revealing possible problematic zones in the estimated fresh-saltwater interface.
