### Resistivity and induced polarization inversion software (free to download)

**ProfileR**has been designed for surface array resistivity imaging. ProfileR is an inverse solution for a 2-D resistivity distribution based on computation of 3-D current flow using a quadrilateral finite element mesh. The inverse solution is based on a regularised objective function combined with weighted least squares (an Occams type solution). The code supplied has been compiled for Intel compatable processors, users working on different platforms should contact the author.

ProfileR has no built in graphical interface. The user can use his/her own software for graphical output (e.g. Surfer). Alternatively the interface Zondres2D written by Alexander Kaminsky can be used. An unlicenced free (older) version is attached in the download bundle along with a readme file to explain how to get started. The plot shown here is an example of the output from the Zondres2D graphical interface written for

**ProfileR**by Alexander Kaminsky

The

**R**family of codes

A set of four codes have been developed to allow forward and inverse modelling of 2D and 3D DC resistivity and induced polarization (complex resistity). The meshing and data input are similar for all codes.

**R2**is a forward/inverse modelling code for 2-D resistivity problems. Regions are discretised in a quadrilateral or triangular mesh. The inverse solution is based on a regularised objective function combined with weighted least squares (an Occams type solution) as defined in Binley and Kemna (2005). Electrodes can be placed on the ground surface or in boreholes. A 32bit and 64bit version for Intel compatible processors are provided in the download.

**R2**will output forward and inverse models in x,y,z ASCII format suitable for plotting with third party software.

**R2**also produces vtk formatted output allowing quick plotting with Paraview

**cR2**is is a forward/inverse modelling code for 2-D complex resistivity (induced polarization) problems.

**cR2**is based on

**R2**and has a similar input/output structure.

**R3t**is a forward/inverse solution for 3D current flow in an unstructured (tetrahedral) or structured (triangular prism) mesh. The inverse solution is based on a regularised objective function combined with weighted least squares (an Occams type solution) as defined in Binley and Kemna (2005).

**R3t**runs in a 64bit Intel compatible processor (64bit is necessary for running large problems).

**cR3t**is a forward/inverse solution for 3-D complex resistivity (induced polarization) problems using unstructured (tetrahedral) or structured (triangular prism) mesh.

**cR3t**using the same meshing structure as

**R3t**but treats resistivity as a complex parameter (defined in terms of magnitude and phase angle).

**cR3t**runs in a 64bit Intel compatible processor (64bit is necessary for running large problems).

### Links to software useful for the above codes

ParaView - open source data visualisation software - ParaView

Mesh generator with graphical interface - Gmsh

- a new Python GUI for R2, R3t, cR2 and cR3t - ResIPy