Jamesina J. Simpson

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—This paper reports the first application of an optimized geodesic, three-dimensional (3-D) finite-difference time-domain (FDTD) grid to model impulsive, extremely low-frequency (ELF) electromagnetic wave propagation within the entire Earth-ionosphere cavity. This new model, which complements our previously reported efficient 3-D latitude-longitude grid, is(More)
Advances in computing technologies in recent decades have provided a means of generating and performing highly sophisticated computational simulations of electromagnetic phenomena. In particular, just after the turn of the twenty-first century, improvements to computing infrastructures provided for the first time the opportunity to conduct advanced,(More)
We theoretically investigate light scattering from a bi-sphere system consisting of a gold nanosphere and a lossless dielectric microsphere illuminated at a resonant optical wavelength of the microsphere. Using generalized multisphere Mie theory, we find that a gold nanosphere 100 times smaller than the dielectric microsphere can be detected with a(More)
—This paper reports the application of an efficient finite-difference time-domain (FDTD) algorithm to model impulsive extremely low frequency (ELF) propagation within the entire Earth-ionosphere cavity. Periodic boundary conditions are used in conjunction with a three-dimensional latitude-longitude FDTD space lattice which wraps around the complete(More)
—This letter reports the initial application of the finite-difference time-domain (FDTD) method to model extremely low-frequency (ELF) propagation around the entire Earth. Periodic boundary conditions are used in conjunction with a variable-cell two-dimensional TM FDTD grid, which wraps around the complete Earth sphere. The model is verified by numerical(More)
—This letter proposes a novel extremely low frequency (ELF) radar for major oil deposits. Using our recently developed whole-Earth electromagnetic wave propagation model based upon the finite-difference time-domain method, we have determined that detection of the radial (vertical) component of the scattered-field provides a sensitive means to detect oil(More)
[1] We report what we believe to be the first three-dimensional computational solution of the full-vector Maxwell's equations for hypothesized pre-seismic electromagnetic phenomena propagated within the entire Earth-ionosphere cavity. Periodic boundary conditions are used in conjunction with a variable-cell finite-difference time-domain (FDTD) space lattice(More)
—This letter reports the initial application of a geodesic finite-difference time-domain (FDTD) grid to model impulsive extremely low frequency electromagnetic wave propagation about the Earth sphere. The two-dimensional transverse-magnetic grid is comprised entirely of hexagonal cells, except for a small fixed number of pentagonal cells needed for grid(More)
—An effective absorbing boundary condition (ABC) based on the second-order approximations of Engquist and Majda's wave equations is presented for terminating three-dimensional finite-difference time-domain (FDTD) models employing the E-J collocated magnetized cold plasma algorithm. Numerical tests demonstrate that this ABC can effectively terminate(More)
—This letter proposes a novel extremely low frequency (ELF) radar for localized D-region (altitude < 95 km) ionospheric anomalies that have been generated by natural geophysical processes. The proposed system would use the former U.S. Navy Wisconsin Transmitting Facility as a distant well-characterized impulsive ELF source. Sample calculations that(More)