Design and Realization of a Buoy for Ocean Acoustic Tomography in Coastal Sea based on NB-IoT Technology

This paper presents the design and realization of a buoy for coastal ocean acoustic tomography based on the narrowband-internet of things (NB-IoT) technology. The body of the buoy is made of unplasticised polyvinyl chloride (PVCU) pipe material. The buoy consists of two main parts: surface pharos and buoy body. The surface pharos part further consists of NB-IoT and global positioning system (GPS) modules which realize buoys networking, distributed time synchronization, and remote real-time monitoring and control. Whereas, the built-in data reception system, signal transmission, and power amplifier are inserted in the buoy body. The system uses 1pulse per second GPS (1PPSGPS) to trigger signal for synchronizing transmission and reception. The buoys are tested in the acoustic tomography experiment conducted at the coast of east China sea (ECS) in 2014. From the experiment, the results show that the self-organizing network (SON) with this kind of buoys can work well and achieve better signals which are successfully applied to the inversion of sound speed profile (SSP). The accuracy of the SSP inversion indicates system reliability and stability. The average power for the whole system is 1W. With lower power consumption and cost, the system is able to be widely and equally applied to ocean acoustic tomography, marine monitoring, and other fields.