Tracking of Localized Sensor Node using Single-beam Echo Sounder

In the current scenario, the seabed is extensively mapped using multibeam sonar modules which in return provides the intricate details of the bed. A sensor node on a sea bed can be used to store or to retrieve the data. A low-cost single beam echo sounder provides the best use of localizing a node in underwater environments where full area mapping is not necessary. The multi-beam sonar is not suited for the purpose because of the requirement for high computational power and high cost. A single beam Echo sounder is typically used to determine the depth of the sea, but the paper aims to track a sensor node with the limited 30-degree beamwidth of the single beam echo sounder module. This full-scale area mapping is achieved by a pan-tilt mechanism using the underwater Servo motors. A sensor node can be detected by transmitting an acoustic wave by the Echo sounder which is mounted over a 3D printed housing supported by Servo motors. This paper represents a cost-effective setup to scan the full area and localize a sensor node in an unknown underwater environment. The setup has been tested for two cases underwater and the results assure the correct localization.