Study On Underwater Acoustic Active Homing Signal Processing Method Based On Adaptive Array

Underwater homing system is the key for torpedo to effectively attack the target and is an important aspect in the field of underwater acoustic engineering research.Its research achievements have been applied in many fields of engineering practice.This paper studies the signal processing technology of homing system based on the torpedo flank array sonar and adaptive array is utilized in order to search for an underwater active acoustic homing technology to improve the detecting range and the detectability under the condition of low signal to noise ratio of the torpedo's homing system.Active sonar waveform design and adaptive array processing are deeply discussed and novel modified methods are proposed in this paper.The main work can be summarized as follows:1.Active sonar waveform design is deeply analyzed.By building the theoretical model of waveform design,this paper analyzes the performance of the commonly used sonar signals.Two specific signals are used as examples to study the frequency modulation and phase modulation in pulse compression waveform design and a new hybrid waveform is proposed based on these two types of modulation.This hybrid waveform's frequency modulation and phase modulation are accomplished between adjacent pulses and interior single pulse respectively.The new waveform's performance is analyzed in four aspects and the simulation results shows that it has good resolutions,lower range-Doppler coupling,better matched filtering output and robust reverberation performance.2.The theory of adaptive signal processing is deeply studied in this paper and the basic theory and classical algorithm of adaptive signal processing are discussed from two aspects of time domain and space domain.This paper focuses on the field of adaptive space domain processing,compares the classical adaptive and non-adaptive beamforming methods,and deduces and analyzes two typical quiescent pattern synthesis methods.3.The particle swarm optimization algorithm is introduced in detail and its basic ideas and mathematical models are discussed in this paper.This applies particle swarm optimization to adaptive pattern control and proposes a novel fitness function based on maximum signal to noise ratio criterion.A modified particle swarm optimization algorithm based on multi-virtual-interferences combined with linear constrained minimum variance is proposed and deeply discussed in this paper.