Distortion radar signal modelling method under time-varying plasma sheath

Abstract

The invention discloses a distortion radar signal modelling method under a time-varying plasma sheath. The problem that the traditional radar signal model is hard to perform simulation and analysis ona modulation effect received by a distortion radar signal is realized. The realization process is as follows: establishing an electronic density model of the time-varying plasma sheath; computing a plasma sheath transmission coefficient and amplitude and phase thereof; computing to obtain the distortion radar signal model; and performing time-frequency processing on the distortion radar signal model. Through the modelling and time-frequency processing on the distortion radar signal under the time-varying plasma sheath, the distortion radar signal amplitude and phase modulation condition and time-frequency curve intercept and slope change thereof are determined. Through the method disclosed by the invention, the disadvantage that the traditional linear frequency-modulation pulse radar model cannot reflect the modulation effect of the time-varying plasma sheath is remedied, thereby laying the foundation for developing the related research about modulation effect compensation received bythe distortion radar signal; and the modelling method can be used for the signal parameter estimation and research under an electronic reconnaissance field.

Description

technical field [0001] The invention belongs to the technical field of electronic reconnaissance, and mainly relates to the modeling of radar signals under the time-varying plasma sheath, in particular to a modeling method for distorted radar signals under the time-varying plasma sheath, which is used for radar under the plasma sheath Electronic reconnaissance of signals. Background technique [0002] When a hypersonic vehicle penetrates the atmosphere, due to the intense friction between its surface and the air, the surrounding gas is ionized to form a layer of plasma covering the surface of the vehicle, that is, the plasma sheath. The charged particles mainly composed of electrons inside the sheath absorb, reflect and scatter electromagnetic waves. When the electromagnetic signal passes through the plasma sheath, its amplitude and phase are modulated accordingly, which directly leads to the distortion of the electromagnetic wave signal. This modulation seriously interfere...

AI Technical Summary

Problems solved by technology

This time-varying characteristic will produce a more complex amplitude-phase modulation effect on the signal. In addition, considering the particularity and complexity of the radar signal, the signal is multi-frequency, or even frequency-modulated or frequency-hopping. The steady-state plasma sheath pair It is difficult to reflect the influence of the time-varying plasma sheath on the modulation of radar signals in the relevant research on the influence of single-frequency signals;

[0005] The existing traditional radar signal modeling methods are very mature, but the modulation effect on the amplitude and phase of the distorted radar signal under the time-varying plasma sheath cannot be analyzed only by traditional modeling methods

If only the traditional radar signal model cannot reflect the parasitic modulation of the plasma sheath, it cannot describe the distorted radar signal under the plasma sheath more accurately

[0006] Therefore, when analyzing the distorted radar signal under the time-varying plasma sheath, the above method is no longer tried. Objectively, a realistic time-varying plasma sheath distortion radar signal modeling is required to modulate the time-varying plasma sheath. to analyze

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