Time Synchronization Algorithm of Underwater Sensor Based on Doppler Velocity Measurement

Time synchronization is the key technology of underwater sensor networks. Due to the high propagation delay and Doppler frequency shift of underwater acoustic communication in the ocean, the land-based time synchronization algorithm using radio frequency communication can not be directly applied to the underwater environment. Based on the principle of Doppler velocity measurement and the mobility of nodes under water, this paper proposes a new time synchronization CD-Sync algorithm. The cluster model with clustering characteristics is used to select a reasonable cluster head node and synchronize with the water surface beacon node within the cluster. In the process of synchronization, the synchronization node uses Doppler principle to estimate the relative moving speed between nodes, so as to calculate the propagation delay between nodes. Experimental results show that, compared with MU-Sync algorithm based on clustering time synchronization and NU-Sync algorithm based on distributed time synchronization, this algorithm can shorten the distance between nodes and accelerate the convergence speed of synchronization between nodes, while effectively improving the accuracy of time synchronization.