A Survey of Localization Techniques for Underwater Wireless Sensor Networks

With the continuous development of marine resources, the position of Underwater Wireless Sensor Network (UWSN) is becoming more and more important, and UWSN needs to know the location of sensor nodes when completing tasks such as marine data collection, environmental monitoring, and aiding navigation, etc. Accurate sensor node location information is the key to effective acquisition of underwater data. The key to effective underwater data acquisition is accurate sensor node location information. Due to the influence of the environment, global positioning system (GPS) signals cannot be propagated underwater, so hydroacoustic communication becomes the best choice for node positioning. However, the unstable underwater environment brings a series of challenges to hydroacoustic communication, such as high channel bit error rate, low bandwidth, large propagation delay, and obvious multipath effect. According to the characteristics and challenges of hydroacoustic communication, this paper classifies the localization algorithms of underwater wireless sensor networks into (i) distance-based and distance-free localization algorithms, (ii) single-hop and multi-hop localization algorithms, and (iii) distributed and centralized localization algorithms.