Absorption losses in seawater for a rectangular electromagnetic pulse

Transient solutions for a class of waveforms in a general lossy medium have been published recently (H.F. Harmuth, 1986). These solutions are expressed in terms of improper integrals and are functions of the conductivity of the medium. Numerical evaluation of these integrals for the case of seawater results in ill-conditioned problems giving rise to computational overflows. An approximate closed-form transient solution valid for propagation of signals in seawater is developed. An electromagnetic signal with the initial time variation of a rectangular pulse with a given width is assumed. This solution is used for the computation of the absorption losses in seawater as a function of propagation distance