Wireless networks for under water surveillance

In this user report, the initial work in the project: wireless networks for underwater surveillance, is described. The project is a part of the Swedish Research Institute´s strategic research kernels. The aim is to investigate how a easily deployable wireless network for surveillance of water volumes can be implemented. The sensor network can be placed at the sea floor and communication with the world around is done by acoustic underwater communication, the equipment is intended to be battery powered. The focus in the research is at the signal processing where distributed detection is a main area. a simulation model of the network including detection and the limitations of the communication has been developed. The distributed detection is in its present state built on the sharing of measurements amongst the nodes, thereafter a decision is taken by voting. If the aloternative that an intrusion is going on wins, an alarm is sent to the command centre, afterwards the nodes return to surveillance mode. As an example has the method been applied to detect scuba divers. The acoustic features for the breathing sounds have been used in the network and the results are good. The work will continue during 2009.