  A new finite difference method on irregular, locally perturbed rectangular
grids has been developed for solving electromagnetic waves around curved
perfect electric conductors (PEC). This method incorporates the back and forth
error compensation and correction method (BFECC) and level set method to
achieve convenience and higher order of accuracy at complicated PEC boundaries.
A PDE-based local second order ghost cell extension technique is developed
based on the level set framework in order to compute the boundary value to
first order accuracy (cumulatively), and then BFECC is applied to further
improve the accuracy while increasing the CFL number. Numerical experiments are
conducted to validate the properties of the method.
