Important

In the spring of 2022, a new suite of FDEM OcTree codes were compiled: E3DRH, E3DRH v2 and E3DRH v2 tiled. These codes use a right-handed coordinate system; as opposed to the modified left-handed coordinate system used by E3D, E3D v2 and E3D v2 tiled. You are currently viewing the manual for the package which uses ‘e3drh_v2_tiled.exe’ to forward model and invert FDEM data. The manual for the original E3D v2 tiled package (which uses ‘e3d_v2_tiled.exe’) can be found here .

3. Elements of the Program

This section provides a brief description of each program in the E3DRH version 2 tiled package. In addition, we describe the file formats for all input and supporting files used by the coding library.

3.1. Program Library

The main executable programs within the AEM program library are:

  • e3drh_v2_tiled: Single executable file for carrying out forward modeling and inversion of FEM data

  • create_octree_mesh_e3d_v2_tiled: creates a global OcTree mesh for the inversion based on the survey geometry and a set of local OcTree meshes about each transmitter and its receivers

The following Octree utility programs are also used:

  • blk3cellOct: creates a conductivity model on the OcTree mesh

  • extract_mesh: extracts a specified local OcTree mesh from a hexidecimal file containing all local meshes

  • create_weight_file: creates cell weighting for the recovered model

  • interface_weights: creates weights on the faces of cells for the recovered model

3.2. Main Input Files

Here, we describe the main input files for executables contained with the E3DRH version 2 tiled package.

3.3. Supporting Files

Here, we describe the formats of supporting files used to run e3drh_v2_tiled.exe. The input files for each executable program are described in the running the programs section.