The passive hidden mobile node time synchronization algorithm used in underwater acoustic networks

A time synchronization algorithm for hidden mobile node (HMB), which can only receive signals, joining an existing synchronized underwater Acoustic (UWA) sensor network (UASN) is proposed. In order to obtain the location of the HMB or communicate with it, the local time of the HMB should synchronize with the UASN. However, the propagation delay in UWA channels could not be ignored compared to electromagnetic radio channels. In the proposed algorithm, the HMB do the uniform linear motion in a certain direction, and the clock drift could be solved. After the derivation of the solution equations and the MATLAB simulation, it was proved that this algorithm is useful to reduce time error and improve the node localization accuracy in specific underwater circumstance.