Engineering topics
Publications and source records attributed to Smith, Torquil.
Program tprimarywholesp.f90 calculates primary field d Bz / dt , directly in the time domain, for a unit strength magnetic dipole source pulse in a conducting medium (whole space). The source pulse wave function may be a step function turn-off, or square or triangular pulse of arbrary duration, or a ramp turn-off.
Program invspheroid6.f inverts time domain measurements of normalized magnetic dipole polarizabilities in axial and transverse directions, for the parameters of a conducting magnetic (ferrous) spheroid: axial and transverse diameters, relative magnetic permeability and conductivity. It uses the sphere/spheroid approximation of J.T. Smith and H.F. Morrison, 2006, "Approximating spheroid inductive responses using spheres" (Geophysics, vol 71, G21-G25). It estimates uncertainty in the inverted parameters, based on a Monte Carlo method using multiple inversions with additional noise added to the data. The transmitter time function may be a step function pulse, a square wave pulse, or a half sine of given duration , at a given repetition rate. Any subset of spheroid parameters may be held fixes while solving for the others.