simpeg.electromagnetics.time_domain.Simulation3DElectricField.getAdc#

Simulation3DElectricField.getAdc()[source]#

The system matrix for the DC resistivity problem.

The solution to the DC resistivity problem is necessary at the initial time for galvanic sources whose currents are non-zero at the initial time. The discrete solution to the 3D DC resistivity problem is expressed as:

Adcϕ0=qdc

where Adc is the DC resistivity system matrix, ϕ0 is the discrete solution for the electric potentials at the initial time, and qdc is the galvanic source term. This method returns the system matrix for the nodal formulation, i.e.:

Adc=GTMeσG

where G is the nodal gradient operator with imposed boundary conditions, and Meσ is the inner product matrix for conductivities projected to edges.

The electric fields at the initial time e0 are obtained by applying the nodal gradient operator. I.e.:

e0=Gϕ0

See the Notes section of the doc strings for resistivity.Simulation3DNodal for a full description of the nodal DC resistivity formulation.

Returns:
(n_nodes, n_nodes) sp.sparse.csr_matrix

The system matrix for the DC resistivity problem.