Investigation of a 3-D Undersea Positioning System Using Electromagnetic Waves
Ryosuke Kato, Masaharu Takahashi, Nozomu Ishii, Qiang Chen, Hiroshi Yoshida
Abstract
When divers rescue people from accidents at sea, they are in danger because of obstacles floating in the sea. If divers can confirm their own position, their activities will become much safer. In this study, assuming that we specify the positions of the divers performing rescue operations, to support their work, we investigate an undersea positioning technology using electromagnetic waves with low frequencies, i.e., 10 kHz. In previous studies, an ultra-long wave of 10 kHz was theoretically attenuated at 3.5 dB/m. In addition, a simulation of position estimation in the vertical section of the sea was reported. In this study, we indicate the superiority of using receiving signal strength (RSS) to the phase difference between a transmitted and received signal. We also investigate an algorithm for position estimation wherein the antenna characteristics and two propagating rays of electromagnetic waves at sea are considered. Finally, we estimate the position of the transmitting antenna at depths of 1 to 8 m using our algorithm.