A Novel Underwater Target Detection Method Based on Low-Frequency Magnetic Signal Generated by Portable Transmitter

Underwater target detection technology plays an irreplaceable role in geoscience especially oceanography. However, there are several existing defects with the conventional underwater target method, such as the permeable depth in seawater is shallow (lasers) and the volume of the whole system is huge (sonar). Therefore, a novel underwater target detection method based on low-frequency (LF) magnetic signal generated by a rotating permanent magnet (PM) [rotating magnet-based transmitter (RMBT)] is proposed in this work, which can not only detect over a long distance in seawater because LF signals attenuate less in lossy media but can also greatly reduce the size and power consumption of conventional detection system because of 'A MEchanically Based Antennas' (AMEBAs) technology. Theoretical analysis and simulation model based on this method are carried out as well. What is more, the selection of the optimal frequency of the magnetic signal for detection is discussed in detail. According to the simulation results, the underwater target detection method proposed in this work is of great feasibility, which will lay the foundation for future tests involving the implementation of an efficient and small form-factor underwater detection system.