Underwater multi-hop target tracking algorithm based on bidirectional modified sound speed profile model

Underwater target tracking accuracy is often hindered by acoustic wave propagation paths and communication delays, while long-distance communication nodes shorten the system's lifetime due to high energy consumption. To address this challenge, we present an underwater multi-hop target tracking algorithm based on a bidirectional modified sound speed profile model (MHOP-BMSSP). MHOP-BMSSP obtains the transmission time using the sound speed profile model and correct transmission time with bidirectionally multiplexing nodes flight time. On the other hand, MHOP-BMSSP utilizes hydroacoustic system connectivity to divide the communication radius based on node density, which reduces transmission energy consumption through multi-hop communication. Nodes are dynamically selected based on hop information and residual energy with different communication radii, while other nodes enter sleep. The selected nodes are used in a ranging model to obtain measurement values. Finally, the difference between observation and measurement values is used to adaptively adjust the measurement noise value of the Unscented Kalman Filter algorithm to complete the adaptive tracking of the nodes. Experimental results show that MHOP-BMSSP improves network tracking accuracy and efficiency and effectively extends network lifetime.