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To investigate the electromagnetic scattering problem related to a foil in a turbulent hypersonic plasma environment, the scattering field formulas for hypersonic plasma turbulence were improved by applying the anisotropic power spectrum. Using the theory of electromagnetic scattering of a conducting object, the second moment of a conducting object's scattering field is obtained in the hypersonic plasma turbulence. Finally, the backscattering cross-section of the foil surrounded by the hypersonic plasma turbulence was calculated. The results showed that the fractal dimension led to an increase in the complexity of the hypersonic turbulent structure, and thus had a greater influence on the electromagnetic wave scattering. The scattering cross-section of the foil in the hypersonic turbulence decreases rapidly. Meanwhile, the anisotropic parameters in the model represent scale-dependent stretching of the turbulent eddy. As the anisotropic parameters of the turbulence increase, there will be less scattering of the hypersonic turbulence. At this point, the total scattering cross-section of the foil in hypersonic plasma turbulence increases gradually. By improving the aerodynamic shape of the aircraft, it can produce a large number of anisotropic turbulent eddies which can effectively improve the passive jamming capability when the foil is cast.

On the basis of the fractal theory and measurements of hypersonic turbulence, the spectral index, and two-dimensional (2D) power spectrum of the refractive index fluctuation are derived, and the 2D band-limited Weierstrass fractal function is applied to simulate the refractive index fluctuation in hypersonic turbulence. Thus, the impact of hypersonic turbulence on synthetic aperture radar (SAR) imaging system is simulated using the fractal phase screen method. Results show that the resolution of SAR imaging is severely deteriorated under the influence of hypersonic turbulence. The phase error caused by the turbulence microstructures in the plasma sheath becomes more apparent with the increase in the fractal dimension of the hypersonic turbulence. The larger Reynolds number associated with the hypersonic turbulence results in a more evident microstructure fluctuation and inferior imaging quality. Furthermore, when an aircraft flies at high speed, the azimuth focus is considerably sensitive to the turbulence microstructure along the direction of flow field. Consequently, hypersonic turbulence in the plasma sheath has a significantly larger effect on the azimuth than on the range in point-target imaging.

The experimental fractal measurements of hypersonic turbulence are used to calculate the scaling exponent, spectral index, and power spectrum of hypersonic turbulence. The characteristics of electr...

In this study, the new fractal model and power spectrum of plasma sheath turbulence are established based on the fractal dimensions in hypersonic turbulence that were measured through experiments. The expression for beam spot size, scintillation index, angle-of-arrival fluctuation, and beam wander are obtained from the power spectrum. Finally, the propagation characteristics of a Gaussian beam in a turbulent plasma sheath are simulated. The authors’ results indicate that plasma sheath turbulence can lead to amplitude and phase variations. A larger variance in the plasma sheath turbulence causes a more evident refractive index fluctuation and a greater effect on the Gaussian beam propagation characteristics. On the contrary, a larger Reynolds number reduces the effect of the plasma sheath turbulence on the Gaussian beam. This new power spectral model is fundamental to understanding Gaussian beam propagation in plasma sheath turbulence and may provide a reference for the imaging and communication system under the effect of plasma sheath turbulence.