Excitation and power spectrum analysis of electromagnetic radiation for the plasma wake of reentry vehicles

The plasma wake of reentry vehicles has the advantages of extensive space range and long traceability, which provides new possibilities for the detection and monitoring of reentry vehicles. Based on the Zakharov model, this work investigates the excitation and power spectrum characteristics of electromagnetic radiation for the plasma wake of a typical reentry vehicle. With the aid of parametric decay instability, the excitation condition of electromagnetic radiation for a typical plasma wake is evaluated first. The power spectrum characteristics of electromagnetic radiation, including the effects of both the flight parameters and incident wave parameters are analyzed in detail. The results show that when the phenomenon of excited electromagnetic radiation occurs, plasma wakes closer to the bottom of the vehicle and with faster speeds require higher incident frequencies and thresholds of the electric field. As the frequency of the incident wave increases, peaks appear in the power spectra of plasma wakes, and their magnitudes increase gradually. The frequency shifts of the secondary peaks are equal, whereas, the peaks of the downshifted spectral lines are generally larger than those of the upshifted spectral lines. The work in this paper provides a new idea and method for the tracking of reentry vehicles, which has potential application value in the field of reentry vehicle detection.