基于NTP和IEEE1588海底观测网时间同步系统

NTP/IEEE1588-based time synchronization system in seafloor observatory network

为了实现深海海底观测网时间同步,针对海底观测网通信网络拓扑结构,提出基于网络时间协议(NTP)和IEEE1588协议的时间同步应用方案.介绍NTP和IEEE1588(PTP)协议时钟同步原理.设计岸基站、接驳盒层、观测仪器层进行时间同步的硬件结构.该系统以岸基站PTP主时钟接收到的GPS/北斗双参考源的卫星信号为时间源,解码输出NTP同步信号和PTP同步信号经由光纤以太网通过深海光电复合缆进行远程传输,利用各层时间同步装置获取精确时间.开展实验室环境下的时间同步监测实验.结果表明,PPS信号时间同步精度小于500ns,NTP时间同步精度小于400μs,PTP时间同步精度小于3μs.

An application scheme based on network time protocol （NTP） and IEEE1588（PTP）was pro- posed to achieve accurate time synchronization for deep seafloor observatory network according to the com- munication topological structure. The principles of NTP and IEEE1588 were analyzed. The frameworks for time synchronization of shore station, undersea junction box layer and submarine observation instru- ment layer were designed. NTP and PTP synchronous signals were decoded by PTP master clocks on shore station. PTP master clocks received signals from GPS/Beidou double navigation satellite systems as refer- ence time source. NTP and PTP synchronous signals were remote transmitted by deep sea optic electric composite cable through Ethernet passive optical network. Accurate time can be achieved by time synchro- nization devices in each layer. The laboratory environment synchronization monitoring experiments were performed. PPS signal time synchronization can reach a precision of less than 500 ns; NTP time synchroni- zation can reach a precision of less than 400μs; PTP time synchronization can reach a precision of less than 3μs.