Plume effect on radar cross section of missiles at HF band

The radar cross section of missiles at HF band is affected by the presence of the missile plume. In fact, although the plume is transparent at microwave frequencies, it reflects almost the totality of the energy at the HF band. In this paper, we evaluate the effect of the missile plume on its radar cross section (RCS) at HF band. In order to achieve this goal we: (1) verify that the missile plume can be physically represented by a plasma through a chemical analysis of the combustion; (2) define the time-varying non-linear differential equation that rules the electron density equilibrium in the plume; (3) solve the time-varying non-linear differential equation in order to evaluate the length of the plume that contributes to the RCS calculation; (4) evaluate the RCS of the missile+plume by means of the method of moments (MoM). As a numerical case, the application of both a surface and sky wave over the horizon (OTH) radar has been considered. Specifically, the RCS (as a function of the incidence angle) of the missile during the boost phase trajectory has been evaluated.