3.3.5. Model File

For a given model, the model file has the following format:


\(m_{1,1,1}\)
\(m_{1,1,2}\)
\(\;\vdots\)
\(m_{1,1,nz}\)
\(m_{1,2,1}\)
\(\;\vdots\)
\(m_{1,nx,nz}\)
\(m_{2,1,1}\)
\(\;\vdots\)
\(m_{i,j,k}\)
\(\;\vdots\)
\(m_{ny,nx,nz}\)


where \(N=nx \times ny \times nz\) is the total number of cells in the corresponding tensor mesh. Cells in the x and y directions are organized E to W and S to N, respectively, while cells are organized top to bottom in the vertical. Thus \(m_{1,1,1}\) is the top southwesternmost model value and \(m_{ny,nx,nz}\) is the bottom northeastermost model value.

3.3.5.1. Conductivity Models

For conductivity models, conductivity values are entered in units S/m.

3.3.5.2. Susceptibility Models

For background susceptibility models, values are entered in SI units.

3.3.5.3. Active Cells Model

In this case, cells are assigned a value of 1 if they are active during the inversion and 0 if they are not (i.e. air cells). Cells designated with a 0 in the active cells model are given a value of \(\sigma = 10^{-8}\) S/m and \(\chi=0\) SI in the inversion.