Finite-Element Meshes

The Finite-Element mesh is the discretised representation of the area of interest. The mesh is comprised of nodes (1D, points) and triangles (2D, constructed of three nodes each). Each triangle will later hold a constant subsurface property, such as resistivity magnitude or resistivity phase (sometimes also represented using a complex resistivity).

The mesh also must include all electrode positions and must specify the type of boundary condition on each 1D boundary element.

What things to consider when creating a mesh?

  • In order to achieve suitable modelling accuracy, make sure to use a finer mesh discretisation around electrodes. Also make sure to have at least 2 nodes between adjacent electrodes.

  • Even when using mixed-boundary conditions, make sure to add enough space towards the nearest non-surface boundary. As a rule of thumb, use at least 2 electrode distances.

  • Make sure to add enough depth (z-direction) to the mesh. The absolute minimum is 0.2 * maximum electrode distance.