Measurement of an undersea positioning system using radio waves

Abstract

In Japan, the number of water accidents is approximately 1,300 per year, which is almost constant in recent years. Although divers rescue people in the case of water accidents, there are various obstacles in the sea. Then, divers are always surrounded by a lot of dangers in the rescue activities. Therefore, assuming that identifying the locations of divers supports their rescue operations, we investigate an undersea positioning system using radio waves in the VLF band (10-kHz). According to previous research, radio waves of 10-kHz are theoretically attenuated at 3.5 dB/m, and can be transmitted in the distance of 30 m and more. In addition, a numerical simulation of a three-dimensional undersea position-estimation system has already been reported. In this study, we measured received signals at the real sea and showed the position-estimation results employing the algorithm for an undersea position estimation.