Study On Troposcatter Communication With Coherent Acoustic Wave Disturbance

Troposcatter communication mainly utilizes the scattering characteristics of turbulence to realize the long-distance transmission of electromagnetic wave.It is another important high reliability communication means besides satellite communication and microwave communication in field conditions.Starting from the basic mechanism of acoustic disturbance to the troposphere,the effective transmission of electromagnetic waves is realized by using the ‘artificial inhomogeneous body' in the troposphere stimulated by acoustic waves.The relying mechanism of the scattering over-the-horizon transmission mode can be controlled artificially.The performance and parameters of the scattering overthe-horizon transmission mode no longer depend entirely on nature,thus effectively improving the reliability of the scattering communication transmission channel,and promoting the stability of scattering communication.It is a highly cross-integrated innovation of machine learning theory,computational geometry,artificial atmospheric abnormality in clear sky and computational electromagnetics for large-scale problems.In this paper,theoretical modeling and scattering experiments are discussed.The main work is as follows.Firstly,the troposcatter scattering model and its scattering calculation under acoustic disturbance are established.According to the geometrical relationship of troposcatter links,the theory of acoustic interference and the principle of planar source array,the theoretical model of ‘artificial inhomogeneous body' with fluctuation of relative dielectric constant under the condition of coherent acoustic disturbance is established,and the visual description of the shape,size and distribution of ‘artificial inhomogeneous body' is completed.The three-dimensional spatial domain decomposition of the ‘artificial inhomogeneous body' model is carried out,and the outer surface of triangular surface subdivision of each subarea is computed by using the relevant algorithm of computer graphics.On this basis,the radar receiving and receiving waves are dispersed by ray,and the intersection of ray and outer surface of each subarea in the ‘artificial inhomogeneous body' is distinguished by using acceleration algorithm.Further,the outer surface of each sub-area in the ‘artificial inhomogeneous body' is ray tracing method is used to calculate the scattering characteristics of ‘artificial inhomogeneous body'(radar receiving characteristics);the influence of the core factors of the sound source system on the scattering results is analyzed.The simulation results show that the field intensity modulus increases with the increase of the source power and the decrease of the distance between the source elements,and the frequency of the source and the number of the sub-sources of the source array in a certain range is increased,the field intensity modulus increases beyond the range.On the contrary,the field intensity modulus decreases.Finally,the scattering experiment of coherent acoustic disturbance in local atmosphere is designed and explored.Scattering links are built in microwave anechoic chamber,and the core parameters of sound source system,transmitting system and receiving system are analyzed.On this basis,the experimental scheme is improved,relevant scattering experiments are carried out,and the experimental data are compared with the theoretical results.Satisfactory results are obtained.At the same time,the errors are also analyzed in the end.