Abstract This paper presents the 3D modeling program GEMM3D (Geophysical ElectroMagnetic Modeling 3D), a Fortran program for modeling frequency domain electromagnetic responses of geophysical sources in three-dimensional models. The program is an implementation of the Edge Finite Element method, in an electric field formulation, to simulate any electromagnetic source of interest, at all frequencies that are used in the geophysical methods in the quasi-static regime. Its current version includes routines for plane waves and simulation of magnetotelluric data; electrical and magnetic dipoles; circular loops. Other sources and configurations may easily be included with the addition of routines for simulating primary (layered earth) fields. The program includes routines for calculating sensitivities using the Adjoint State method, which makes efficient use of direct solvers for factoring once and solving for multiple systems with the same coefficient matrix. The paper details the methods, the implementation, and the usage of the program. Validation tests are presented for different sources. The program is freely available for use in research and teaching.

中文翻译：

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GEMM3D：用于地球物理应用的电磁场和灵敏度 3D 建模的边缘有限元程序

摘要 本文介绍了 3D 建模程序 GEMM3D（地球物理电磁建模 3D），这是一个 Fortran 程序，用于在三维模型中对地球物理源的频域电磁响应进行建模。该程序是边缘有限元方法的一个实现，在电场公式中，以模拟任何感兴趣的电磁源，在准静态区域的地球物理方法中使用的所有频率。它的当前版本包括平面波和大地电磁数据模拟的例程；电偶极子和磁偶极子；圆形循环。通过添加用于模拟初级（分层地球）场的例程，可以轻松包含其他来源和配置。该程序包括使用伴随状态方法计算灵敏度的例程，这可以有效地使用直接求解器进行一次因式分解并用相同的系数矩阵求解多个系统。论文详细介绍了该程序的方法、实现和用法。提供了针对不同来源的验证测试。该程序可免费用于研究和教学。