Broadband reverberation waveform simulation method based on normal mode theory

Abstract

The invention discloses a broadband reverberation waveform simulation method based on the normal mode theory. The method comprises the following steps that reverberation scattering elements are randomly distributed in space, a scattering echo range and phase modulation signals are set, simulated broadband signals are subjected to sub-band division, ocean reverberation time sequences of sub-bands are calculated respectively, the ocean reverberation time sequences are superposed to obtain an ocean broadband reverberation time sequence at a certain receiving array element, and the method is used for obtaining ocean broadband reverberation time sequences at different receiving array elements through calculation. The method reflects influences of a channel on different frequencies in a band width, simulation errors are small, various factors in reverberation simulation are comprehensively considered, reverberation spatial correlation, space-time characteristic and other physical characteristics can be naturally reflected, and requirements for reverberation data of space-time self-adaptive processing and other new reverberation restraint algorithms can be met.

Description

technical field [0001] The invention relates to the technical field of underwater acoustic engineering, in particular to a broadband reverberation waveform simulation method based on normal wave theory. Background technique [0002] In order to fight against modern quiet submarines, modern active sonar technology is developing in the direction of low frequency, broadband, high power transmission and large aperture reception. Reverberation is essentially formed by the superposition of scattered echoes from a large number of scattering elements in the ocean. It is a unique interference of active sonar, which seriously restricts the active sonar's operating distance. The high-power transmission under the broadband system further enhances the background of ocean broadband reverberation. Anti-reverberation has become a technical bottleneck to improve the performance of active sonar detection. Shipborne sonar, submarine sonar, dipping sonar, torpedo guidance sonar, etc. all face...

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Problems solved by technology

[0004] The traditional reverberation modeling and simulation methods are either used to predict the reverberation level, without considering the phase information, and cannot reflect other characteristics of the reverberation; or based on the time-varying power spectrum of the reverberation, the obtained reverberation sequence cannot preserve the array Inter-element correlation; either limited by special application requirements, factors such as platform movement, directionality of transmitting and receiving array elements, and sound velocity gradient cannot be taken into account

In particular, most of the current ocean reverberation simulations are aimed at the narrowband system, which cannot meet the demand for ocean broadband reverberation data under the broadband system. , which cannot reflect the influence of the channel on different frequencies within the bandwidth. At this time, the simulation error is large and it is difficult to meet the actual needs.

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