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Propagating electromagnetic Ground Penetrating Radar (GPR) waves are
modelled by a three-dimensional, staggered, orthogonal, fourth-order,
finite-difference time-domain (FDTD) numerical approximation to Maxwell’s
electromagnetic field equations. The scheme includes:
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A
wide range of materials with anisotropic, frequency dependent
permittivity, conductivity and, where necessary, magnetic permeability
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Three-dimensional target features and complex sub-surface geometries
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Realistic antenna designs including
shields, signal damping and accurate source signal forms
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‘Memory
variables’ to determine the time, and therefore frequency, dependant
effect of the materials on the propagating electromagnetic wave
 The software is parallelised using
message-passing (MPI) to run over a number of processors. The hardware
employed is either the
KAGe
Supercomputer or multiple Windows-based networked PCs. Each processor
(or node) must have access to the same shared disk storage. The parameters
which govern the modelling scheme are input to each sub-process from a text
file. Modelling then proceeds through a user-defined number of time-steps.
Results are written to disk at defined time-steps. Optionally checkpoints
(dump of all internal data structures) can also be specified to allow the
model to be restarted in case of hardware or power failure. |
