The Lax Wendroff correction is an elegant method for increasing the
accuracy and computational efficiency of finite?difference time?domain
(FDTD) solutions of hyperbolic problems. However, the conventional
approach leads to implicit solutions for staggered?grid FDTD approximations
of Maxwell's equations with frequency dependent constitutive parameters.
To overcome this problem, we propose an approximation that only retains
the purely acoustic, i.e., lossless, terms of the Lax Wendroff correction.
This modified Lax Wendroff correction is applied to an O(2, 4) accurate
staggered grid FDTD approximation of Maxwell's equations in the radar
frequency range (?10 MHz?10 GHz). The resulting pseudo-O(4, 4) scheme
is explicit and computationally efficient and exhibits all the major
numerical characteristics of an O(4, 4) accurate FDTD scheme, even
for strongly attenuating and dispersive media. The numerical properties
of our approach are constrained by classical numerical dispersion
and von Neumann Routh stability analyses, verified by comparisons
with pertinent 1-D analytical solutions and illustrated through 2-D
simulations in a variety of surficial materials. Compared to the
O(2, 4) scheme, the pseudo-O(4, 4) scheme requires 64% fewer grid
points in two dimensions and 78% in three dimensions to achieve the
same level of numerical accuracy, which results in large savings
in core memory.