3. Elements of the Program E3DMT

This section provides a brief description of each program in the E3DMT version 1 library. In addition, we describe the file formats for all input and supporting files used by the coding library.

3.1. Executables

Important

Although described here, this generation of the code may not be supported by GIFtools in the future.

The main executable programs within the E3DMT version 1 program library are:

• e3dmt_fwd: Solves the forward problem. Computes the electric and magnetic response to a 3D conductivity model (fields, and impedance)

• e3dmt: Solves the inverse problem using a direct solver approach (MUMPS). Recovers a conductivity model by inverting MT or ZTEM data. All entries of the impedance tensor or transfer function are needed.

• e3dmt_iter: Solves the inverse problem using an iterative solver approach. Recovers a conductivity model by inverting MT or ZTEM data. All entries of the impedance tensor or transfer function are needed.

• create_octree_mesh_e3dmt: Creates an octree mesh based on the survey file

Common Octree utility programs used with this package include:

• blk3cell: Creates models from a set of blocks on a tensor mesh

• 3DModel2Octree: Converts models from tensor to Octree meshes

• interface_weights: Creates interface weights

3.2. Main Input Files

Here, we describe the main input files for executables contained with the E3DMT version 1 package.

• 3.2.1. Create octree mesh
• 3.2.2. Create octree model
• 3.2.3. Forward modeling
• 3.2.4. Create face weights
• 3.2.5. Inversion

3.3. Supporting Files

Here, we describe the formats of supporting files used to run E3DMT executable files. The input files for each executable program are described in the running the programs section.

• 3.3.1. Survey and Locations File
• 3.3.2. Predicted Data File
• 3.3.3. Observations File
• 3.3.4. Topography File
• 3.3.5. Tensor Mesh File
• 3.3.6. Octree Mesh File
• 3.3.7. Model File
• 3.3.8. Model and Face Weights Files