A self-contained ocean acoustic measurement system is designed in the form of vertical array

based on digital hydrophones.The system consists of multiple digital hydrophones

which are connected to each other via cable.The number of elements and distance between each element can be adjusted.The collected datas are either stored or uploaded in real time by digital hydrophones

and high-speed serial data transmission system is optimally designed based on RS-485 bus

rising/falling edges of serial signal enable bit synchronization time-clock recovery

and data frame is realized with the 8 B/10 B encoded mode

and bus provides remote data transmission along twisted-pair cable at the transmission rate of 15 MB/s

and a primitive synchronization scheme is also given on the bus in reference to IEEE 1588 timing protocol

whose synchronization the maximum error is 0.5 μs.Finally

tests prove that the acquisition effect is good

the system is reliable

with low overall power consumption and each array element is accurate and synchronous

and it can be widely used in underwater array element measurement.