GENERATION OF HIGH-INTENSITY RF PULSES IN THE IONOSPHERE BY MEANS OF IN-SITU COMPRESSION

We demonstrate, using a simple model, that high intensity pulses can b e generated, by making use of the dispersive properties of the ionosph ere, from a modifier of much lower intensity whose frequency is a para bolic function of time. We show that such a frequency-chirped pulse ca n be constructed so that its various components overtake each other at a prescribed height, resulting in large (up to one hundred times) tra nsient intensity enhancements as compared to those achievable from a s teady modifier operating at the same power. We examine briefly one pos sible application: the enhancement of plasma wave amplitudes which occ urs as a result of the interaction of such a compressed pulse with pre -generated turbulence.