Communication through plasma sheaths via Raman (three-wave) scattering process

A mechanism of communication through plasma sheaths which surround vehicles traveling at hypersonic velocities is proposed. The idea is to place a source of an intensive, high frequency electromagnetic pump wave on the vehicle and to use the nonlinearity of the medium to create a backscattered Stokes wave through the interaction of the pump wave with the signal-carrying wave sent by a ground transmitter. Such an interaction will be mediated by the plasma oscillations generated in the process of the resonant absorption of the signal-carrying wave. The advantages of this mechanism for information transfer are that the high frequency pump wave only is present in a small region near the vehicle and that the signal wave can have relatively low frequency.