In underwater observation using underwater vehicles without umbilical cables, such as autonomous underwater vehicles (AUVs), the vehicles are typically monitored with acoustic communication and positioning from a support vessel. Conventionally, the communication and positioning functions have been operated as separate systems. Then interference between the acoustic signals of these functions has to be avoided during the operation. For safer and labor-saving operation, a system that integrates communication and positioning functions has been developed. In this study, the design of the integrated acoustic communication and positioning system and its practical use on operation of underwater vehicles are presented. A chip scale atomic clock is equipped with the system of each node, enabling precise synchronization of the real time clocks. Information of the transmission time of acoustic packet is included in the data. This enables the position of the vehicle to be estimated simultaneously with the reception of the acoustic packet in a one-way transmission. The configuration of the packet and communication protocol have been designed to achieve reliable command transmission, high-rate telemetry of observation data, and safe and automated operation. The system has been practically used on some vehicles such as submersible and AUVs.
Watanabe et al. (Wed,) studied this question.