Target Detection Using Underwater Acoustic Networking

This paper presents a feasibility study for simultaneous underwater acoustic communication (UAC) and target detection using a network of underwater nodes. It can be achieved via anomaly detection in the estimated channel impulse response (CIR) of regular packet transmissions in the network. Such a network could serve as the first step in detecting and localising possible targets, which could then be followed up by the deployment of a sonar-equipped AUV to scan the identified area in more detail. The MAC layer based on Spatial Reuse TDMA (STDMA) fits the traffic requirements of such a network significantly better than contention-based MAC protocols. An enhancement of STDMA packet scheduling that utilises interference cancellation (IC) capabilities at the receivers can further increase the network throughput and, thus, the target detection performance. The simulation study shows that such an approach is feasible from the point of view of network throughput and the probability of the target ``crossing" an active acoustic path. Further work includes the integration of a more detailed acoustic environment model, and the development of a Network and Application Layer to deliver the detection information through the network and to enable target tracking.