The NTU buoy for typhoon observation, part 1: System: NTU buoy for typhoon: System

For a better understanding of the air-sea interactions that occur during typhoons and improved accuracy in typhoon forecasting, the Institute of Oceanography at the National Taiwan University has developed a buoy that can measure meteorological and hydrographic conditions, and transmit the high-precision data in near real-time. The buoy captures various types of meteorological data, including air temperature, air pressure, relative humidity, wind speed and direction, rainfall, and solar radiation. Additionally, the buoy measures key hydrographic data, such as the temperature and salinity profiles of the upper 500-m water layer. The newly designed of buoy system is a low-power-consumption system and it can be in sleep mode between successive samplings to save power energy. The buoy is supplied electric power by lithium batteries and it can support buoy operation for more than 18 months. The sampling interval and data transmission rate are adjustable via Iridium satellite or UHF radio communications. When a typhoon approaching buoy, the operator can transmit a command to buoy via Internet/Iridium satellite communications to change data transmission rate from standard mode to intensive mode. In addition, the raw data can be retrieved through UHF radio communication between the buoy and a nearby ship. A prototype and two improved buoys were deployed off southeastern Taiwan for trial in summers of 2015 and 2016, respectively. These buoys survived nine typhoons and successfully collected important data on all nine of them. The detail of buoy system and mooring design are presented in this paper.