Research of Modulation Feature Extraction from Ship-Radiated Noise

Abstract

Information degree of the future naval battle will be very highly, and Striving for information advantage is the foundation of winning modern naval battle. Accurate and prompt recognition is the premise and foundation of tactical command. Modern naval battle is fast and complicated, and submarine sonar is required to be able to detect and classify targets fast and precisely. So the passive target detection and identification is the important research part in the modern acoustic technique field. Firstly, the mechanism of ship-radiated noise is analyzed. The envelope detection model of the ship noise is built. The envelope spectrum is extracted. Through the purity of the envelope spectrum and the smoothness of the continuous spectrum, I separate the line spectrum, from which the target base-frequency related with the rotate speed of ship screws can be detected. Secondly, the method of extracting frequency features of the ship radiated noise envelop is presented by using double frequency method, which is the basis of the classification.