Disguised Bionic Sonar Signal Waveform Design with its Possible Camouflage Application Strategy for Underwater Sensor Platforms

The covertness of an active sonar is a very important issue and the sonar signal waveform design problem is studied to improve covertness of the system. Many marine mammals produce call pulses for communication and echolocation, and existing interception systems normally classify these biological signals as ocean noise and filter them out. Based on this, a disguised sonar signal waveform design approach with its camouflage application strategy for underwater sensor platforms is proposed by utilizing bio-inspired steganography. We first construct bionic sonar signal waveforms which are very close to the true whale whistle, and then embed these constructed bionic sonar signal waveforms into the true whale call trains to hide the real sonar signal waveforms. According to the time-frequency structure of the true whale whistle, a bionic sonar signal model is established to generate the proposed sonar signal waveforms. A single sonar signal is used to measure the range of the target and a combination of two sonar signals is utilized for measuring its speed. A high-performance range and speed measurement algorithm is deduced in detail. Based on the constructed signal waveforms and the characteristics of false killer whale call trains, a camouflage application strategy is designed to improve the camouflage ability of the sonar signal sequence. Finally, simulation results are provided to verify the performance of the proposed method.