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The Deep-ocean Assessment and Reporting of Tsunamis (officially abbreviated and trademarked as DART〔(DART website with Patent Licensing Application form )〕) system is a component of an enhanced tsunami warning system. == Stations == Each DART® station consists of a surface buoy and a seafloor bottom pressure recording (BPR) package that detects pressure changes caused by tsunamis. The surface buoy receives transmitted information from the BPR via an acoustic link and then transmits data to a satellite, which retransmits the data to ground stations for immediate dissemination to NOAA's Tsunami Warning Centers, NOAA's National Data Buoy Center, and NOAA's Pacific Marine Environmental Laboratory (PMEL). The Iridium commercial satellite phone network is used for communication between 31 of the buoys.〔( tracks tsunami buoys for NOAA )〕 When on-board software identifies a possible tsunami, the station leaves standard mode and begins transmitting in event mode. In standard mode, the station reports water temperature and pressure (which are converted to sea-surface height) every At the start of event mode, the buoy reports measurements every for several minutes, followed by 1-minute averages for 〔http://www.ndbc.noaa.gov/dart/dart.shtml〕 The first-generation DART I stations had one-way communication ability, and relied solely on the software's ability to detect a tsunami to trigger event mode and rapid data transmission. In order to avoid false positives, the detection threshold was set relatively high, presenting the possibility that a tsunami with a low amplitude could fail to trigger the station. The second-generation DART II is equipped for two-way communication, allowing tsunami forecasters to place the station in event mode in anticipation of a tsunami's arrival. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Deep-ocean Assessment and Reporting of Tsunamis」の詳細全文を読む スポンサード リンク
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