A matrix-exponent method is proposed to treat wave radiation and propagatio
n in anisotropic stratified media. By using matrix-exponent formulations, t
he present method is elegant for expressions and reliable for computations.
As an example, the method is used to calculate the ELF excitation of the E
arth-ionosphere waveguide by an equivalent dipole resulting from heating th
e lower ionosphere with modulated HF waves.