Numerical rise time calculations for obliquely propagating BY pulses

Abstract

For planning spread spectrum communication systems over ionospheric HF channels it is important to determine pulse rise times or dispersive bandwidths which are characteristic for wideband propagation. 1(n this paper a numerical technique for the calculation of pulse rise times is proposed. This technique has been developed on the basis of known theoretical results concerning the pulse propagation through a plane stratified ionosphere. The calculations were carried out for several cases of propagation through the lower E-region, using the Jones-Stephenson three-dimensional ray-tracing program. The obtained rise times are in the range from a few μs (for the wave-packet reflected from sporadic- E) to several tens of μs (for the wave-packet propagating nearly along the Pedersen path in the lower E-region). The results are shown to be in good agreement with those previously obtained by other authors, either by measurements or theoretical approaches.