Application of Chaotic Detection Technology to Active Sonar

A Duffing oscillator for detecting weak signal is designed to reduce power consumption and enhance security of the active sonar system. The Duffing equation expresses amplitude and frequency sensitive property when system transits from chaotic to periodic motion. The frequency sensitive property fits for extraction of weak frequency variation through simulation. CW pulse transmitted by active sonar is received to detect range and Doppler shift of echo simultaneously. We improve the Duffing oscillator detection in ultrasonic distance measurement. The measurement is adopted as a criterion of chaotic state. The Duffing oscillator can not detect target because of phase deviation. The solution to this problem is also proposed by time shifting. Computer simulation results show that this is a good time-domain signal processing method which has a lower signal to noise ratio limitation of -20 dB. Compared with the classical active sonar detection method, the presented method reduces the transmitter power consumption and enhances the security of system.