Abstract
Time synchronization and localization in underwater environment are challenging due to high propagation delay, time measurement error, and node mobility. Although synchronization and localization depend on each other and have the similar process, they have been usually handled separately. In this paper, we suggest time synchronization and localization based on the semiperiodic property of seawater movement, called SLSMP. Firstly, we analyze error factors in time synchronization and localization and then propose a method to handle those errors. For more accurate synchronization, SLSMP controls the transmission instant by exploiting the pattern of seawater movement and node deployment. Then SLSMP progressively decreases the localization errors by applying the Kalman filter or averaging filter. Finally, INS (inertial navigation system) is adopted to relieve localization error caused by node mobility and error propagation problem. The simulation results show that SLSMP reduces time synchronization error by 2.5 ms and 0.56 ms compared with TSHL and MU-Sync, respectively. Also localization error is lessened by 44.73% compared with the single multilateration.
Highlights
Ocean infrastructures like offshore plants have been garnering great attention owing to huge potential benefits of marine resources [1, 2]
SLSMP controls the transmission instant by reflecting the fact that node mobility caused by seawater movement like tide and wave follows semiperiodic patterns
We proposed enhanced time synchronization and localization, named SLSMP, using features of seawater movement and sensor deployment
Summary
Ocean infrastructures like offshore plants have been garnering great attention owing to huge potential benefits of marine resources [1, 2]. Necessity of real-time monitoring for marine environment is growing to immediately deal with critical accidents that can be caused by unpredicted events like high temperature of sea water, red tide, oil spill, and so on. According to this trend, many researchers from academic and industrial are studying UWSN (underwater sensor networks) recently. Time synchronization is crucial for various applications such as localization and low-power sleep scheduling MAC protocols, existing synchronization schemes did not fully consider practical issues, like channel access delay. SLSMP controls the transmission instant by reflecting the fact that node mobility caused by seawater movement like tide and wave follows semiperiodic patterns.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
