Development of Smartphone-embedded telemetry drifting buoy for tracking drifting oil patches in the coastal water and field test

For accurately tracking drifting oil patches, a new real time telemetry drifting buoy has been developed. The developed buoy, which utilizes Android smart phone as an electronic device for sensing and telecommunication, can provide its position and additional meteorological data such as wind velocity and direction via cellular phone communication network in real time. The developed buoy is very simple, light weight, cost beneficial as well as high performance so as to contribute to improvement of spilt oil tracking. We conducted field tests using the prototype buoys two times. In the first trial in 2012, we verified its basic function and found that our design concept was rational and found some minor modification could give the system practical usage. In the second trial in 2013, improved prototype buoys were deployed to the field test. In the field test, the buoy worked in nearshore area for many hours without human intervention nor network communication errors and supplied good-quality real-time meteorological data. The obtained data were analyzed and found very useful for tracking drifting oil patches on the sea surface since the buoy provides not only water current information but also wind information. They are also contributory to modeling horizontal turbulent diffusivity of oil patches. This paper shows the design of the buoy and the performance in the field tests. As for the application, this paper also presents a new oil tracking method using the buoy as well as discussion about turbulent diffusivity modeling.