Underwater Acoustic Communication based Coastal Surveillance System

Acoustic waves are the only means of communication underwater over a long distance. This type of multipath communication between transmitter and receiver takes place by reflection from the surface and the floor of the ocean. Generally, the seafloor is not as uniform as the sea surface. Any temporal change in the behavior of the sea surface will have a distinct effect on the strength of the received signal. This idea can detect various kinds of surface activities like layer formation due to pollution, oil spills, or adverse weather conditions. In this paper, a quantitative study has been done to detect such superficial activities on the sea surface between the transmitter and receiver. This kind of system with an array of nodes forming an extensive underwater sensor network can be used for coastal surveillance, pollution monitoring, intrusion detection, and observing sea states. The behavior of different sea surface conditions has been studied in an experimental testbed, and the experimental results may be efficiently used for real-time sea surface activity detection.