Underwater acoustic communication messaging time stamp applied to global time synchronization

This paper presents a new approach to time stamp messages in underwater acoustic communication. Message time stamping is a widely used method for synchronizing two clocks over a cabled or wireless communication, by exchanging time information in pilot messages. In this work we use a National Instruments Field-Programmable Gate Array (FPGA) for performing deterministic hardware time stamp of windowed acquired data, and then we apply a software detection of frame information inside this acquisition window. Frame time stamp in conjunction with global time reference enclosed in the message, provide enough information for achieving synchronization accuracy between two clocks below few microseconds.