Three-dimensional FDTD modeling of impulsive ELF propagation about the earth-sphere
Three-dimensional FDTD modeling of impulsive ELF propagation about the earth-sphere
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DOI：
10.1109/tap.2004.823953
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发表时间：
2004-04
影响因子：
5.7
通讯作者：
J. Simpson;A. Taflove
中科院分区：
文献类型：
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作者：
J. Simpson;A. Taflove
本文报告了应用高效的时域有限差分 (FDTD) 算法来模拟整个地球电离层空腔内的脉冲极低频 (ELF) 传播。周期性边界条件与环绕整个地球圈的三维纬度-经度 FDTD 空间晶格结合使用。东西方向上相邻网格单元的自适应组合可以最大限度地减少接近极点时的单元偏心率，从而在相对较大的时间步长内保持库朗稳定性。该技术允许对脉冲环球 ELF 传播进行直接的三维时域计算，考虑激发、电离层、岩石圈和海洋的任意水平和垂直几何和电不均匀性/各向异性。通过将 ELF 传播衰减结果与文献中报告的相应数据进行比较，验证了数值模型。
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 Earth-sphere. Adaptive combination of adjacent grid cells in the east-west direction minimizes cell eccentricity upon approaching the poles and hence maintains Courant stability for relatively large time steps. This technique permits a direct, three-dimensional time-domain calculation of impulsive, round-the-world ELF propagation accounting for arbitrary horizontal as well as vertical geometrical and electrical inhomogeneities/anisotropies of the excitation, ionosphere, lithosphere, and oceans. The numerical model is verified by comparing its results for ELF propagation attenuation with corresponding data reported in the literature.