A method for synthesizing and modifying cetacean calls

Abstract

The invention discloses a method for synthesizing and modifying cetacean calls. The tonal sound of a cetacean is set as s T (t), the corresponding bionic signal is s b (t), in order to construct s b (t), the s T (t) is divided into M segments, M is a positive integer greater than or equal to 1, using M bionic signal segments to imitate s divided into M segments T (t); finally splicing the M bionic signal segments end to end to get s b (t), by modifying the spliced ​​s b The parameters of (t) realize the modification of tonal sound to meet the effectiveness requirements of bionic camouflage concealed underwater acoustic detection and communication; specifically, the following steps are included: (1) Construct bionic signal s b Time-frequency expression of each bionic signal segment in (t); (2) Construct segmental bionic signal s N (t); (3) Extract the envelope of the tonal sound and use it as the envelope of the bionic signal; (4) Synthesize the bionic signal s b (t); (5) If the tonal sound has harmonics, repeat steps (1) to (4) until the modification is completed.

Description

technical field [0001] The invention belongs to the field of underwater acoustic signal processing, in particular to a method for synthesizing and modifying cetacean calls. Background technique [0002] Due to the active sending of signals, the active sonar detection (Active Sonar Detection, ASD) system and the underwater acoustic communication (Underwater Acoustic Communication, UAC) system are easily found by the underwater detection system. Improve the concealment of ASD signal and UAC signal. Traditional ASD signal and UAC signal concealment techniques can be divided into three categories: low probability of interception (Low Probability of Interception, LPI) technology (first category), LPD (Low Probability of Detection, LPD) technology (second category) and bionic camouflage Covert underwater acoustic detection and communication technology (category III). [0003] LPI technology continuously changes the parameters of traditional artificial signals through frequency h...

AI Technical Summary

Problems solved by technology

However, this type of model can only extract the contour of the tonal sound, and cannot parameterize the contour, so it cannot meet the validity requirements; the second type of model is based on the traditional frequency modulation (Frequency Modulation, FM) signal model, such as linear frequency modulation (Linear Frequency Modulation, LFM) signal and hyperbolic FM signal (Hyperbolic Frequency Modulation, HFM) signal

However, due to the complex and diverse time-frequency structure of tonal sound, the traditional FM signal model has a low degree of freedom and cannot achieve high similarity imitation of various tonal sounds, so it cannot meet the camouflage requirements

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