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A self-locating datum marker buoy (SLDMB) is a drifting surface buoy designed to measure surface ocean currents. The design is based on those of the Coastal Ocean Dynamics Experiment (CODE) and Davis-style oceanographic surface drifters – National Science Foundation (NSF) funded experiments exploring ocean surface currents. The SLDMB was designed for deployment by United States Coast Guard (USCG) vessels in search and rescue (SAR) missions, and is equipped with a Global Positioning Satellite (GPS) sensor that, upon deployment in fresh- or saltwater, transmits its location periodically to the USCG to aid in SAR missions. Additionally, SLDMB are deployed in oceanographic research in order to study surface currents of the ocean. This design has also been utilized by Nomis Connectivity for secure ocean based communications. ==Design== The SLDMB is based on the Davis-style drifter design, which attempts to minimize the effects of wind and surface waves.〔(R. E. (1985). Drifter Observations of Coastal Surface Currents During CODE: The Method and Descriptive View. Journal of Geophysical Research, 90(C3), 14. ).〕 This is accomplished by reducing the area above the ocean surface to small floats and an antenna. Below the surface is a series of drogue vanes to 70 cm. (less than the 1 m Davis-style buoy) in depth, which catch the ocean current, along with electronic equipment that deploys the vanes and antenna, receives the GPS signal and transmits the location to the USCG. SLDMB construction varies by manufacturer, but those used by the USCG consists of four orthogonal drag vanes 0.5m wide and 0.7m high of nylon fabric. These are supported by PVC arms at top and bottom, which extend from a cylindrical hull that contains the electronic equipment. Small floats are attached to the end of each upper arm in order to maintain buoyancy, and a small antenna projects above the SLDMB.〔(I., Mooers, C. N. K., Haus, B., Turner, C., Lewandowski, M. (2007). Technical Report: Surface Drifter Advection and Dispersion in the Florida Current Between Key West and Jacksonville, Florida. Technical Report. ).〕 Deployment of the SLDMB may be accomplished by aircraft (both fixed-wing and rotary) or by ship. SLDMB deployed by aircraft are encased in a tube and attached to a parachute which decreases the impact produced upon hitting the water but without so much drag that the buoy can drift off-course according to USCG SAR guidelines. Upon reaching the ocean surface, the outer casing and parachute break away from the SLDMB, and the spring-loaded antenna deploys.〔 Electronics consist of a GPS receiver, electronic transmitter and sufficient batteries to provide continuous data collection for a period of two weeks to one month.〔 The (METOCEAN iSLDMB ) which received the Canadian Coast Guard Award in 2012 has the following dimensions and equipment:〔[METOCEAN. (2008). METOCEAN SLDMB: Operating & Maintenance Manual (Version 3.0 ed.) Retrieved from http://www.metocean.com.〕 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「Self-locating datum marker buoy」の詳細全文を読む スポンサード リンク
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