The Propagation of a Radar Pulse in Sea-Water
Journal
Journal of Applied Physics
Journal Volume
73
Journal Issue
4
Pages
1581-1590
Date Issued
1993
Author(s)
Abstract
The propagation in sea water of an electromagnetic field in the form of a semi-infinite wave train or a radar pulse generated by an electric dipole is investigated analytically for low frequencies. The frequency-domain formula for the downward-traveling field of a horizontal electric dipole excited by a sinusoidally modulated electric-current pulse is Fourier transformed to obtain an explicit expression for the field at any distance in the time domain. Specific application is made to a wave packet of 25.5 cycles in a time duration of 1 s. The amplitude and phase velocity of the wave packet are determined together with the amplitudes of the initial and final transients. Graphs are displayed and discussed for a range of distances; these show that the amplitude of the wave packet decays more rapidly than the amplitudes of the transients. Possible application to remote sensing in the ocean is considered.
SDGs
Type
journal article