Reproduce: MAG3D v6.0#

Inverting TMI Data Over a Susceptible Block in a Halfspace: Smoothest Least-Squares#

Here, we inverted total magnetic intensity (TMI) data collected over a block within a homogeneous halfspace. We invert for the smoothest model using a bounded least-squares inversion approach; in order to enforce positivity in the recovered model.

The true model consists of a susceptible block (0.025 SI) within a minimally susceptible halfspace (0.0001 SI). The dimensions of the block in the x, y and z directions were are all 200 m. The block was buried at a depth of 200 m. The Earth’s inducing field had an inclination of 65 degrees, a declination of 25 degrees and an intensity of 50,000 nT.

The data being inverted were generated using the UBC MAG3D v6.0 code. Synthetic TMI data were simulated within a 1000 m by 1000 m region at an elevation of 30 m; the center of which lied directly over the center of the block. The station spacing was 50 m in both the X and Y directions. Observed data were sythnetically created by adding Gaussian noise with a standard deviation of 1 nT to the simulated data. A floor uncertainty of 1 nT was assigned to the observed data.

UBC-GIF MAG3D v6.0 Package Details#

MAG3D v6.0 is a voxel cell magnetic forward modeling and inversion package developed by the UBC Geophysical Inversion Facility. This software is proprietary and can ONLY be acquired through appropriate academic or commerical licenses. The numerical approach of the forward simulation is described in the online manual’s theory section. If you have a valid license, there are instructions for reproducing the results (add link).

Running the Inversion#

Step 1: Acquiring a commercial or academic license.#

  • Explain and link to where you would get licenses. Make ABSOLUTELY CLEAR we don’t just give out the licenses willy-nilly.

Step 2: Downloading and extracting assets#

  • Link and instructions for download

Step 3: Running the forward modeling executable#

  • Brief description of what files are needed

  • Link to the manual page where we run the forward simulation