4.1.4. Forward Modeling

The program dcipoctree_fwd.exe performs the 3D forward modelling of DC resistivity and/or IP data on octree meshes.

4.1.4.1. Running the Program

To run the executable, open a command window and type the following:

../../_images/run_fwd.png

Essentially you are calling the path to the executable followed by the path to the input file .

4.1.4.2. Setting Number of Threads with Open MPI

Before running the executable, the number of threads used to carry out all simultaneous processes can be set with Open MPI. This is set in the command window before running the executable. To set the number of threads (nThreads ), use the following syntax:

  • Windows computer: “set OMP_NUM_THREADS=nThreads”

  • Linux (bash shell): “export OMP_NUM_THREADS=nThreads”

  • Linux (csh shell): “setenv OMP_NUM_THREADS nThreads”

4.1.4.3. Units

  • DC data: measured voltage normalized by the transmitter current (V/A)

  • IP data:

  • Conductivity model: S/m

  • Chargeability model: intinsic chargeability - unitless from [0,1)

4.1.4.4. Output Files

The program dcipoctree_fwd.exe creates the following output files:

  • data_dc.txt: The DC potential data

  • data_ip.txt: The IP data (only if the IP or IPL option was set in the input file)

  • model.con | model0.chg: The conductivity and/or chargeability model that was used for forward modelling but now wwith the air cells removed.

  • dcipoctree_fwd.log: Log file which provides details about the parameters used in the forward modelling and diagnostic information about the results.

[data_ip.txt]
[mumps.txt]