A low-cost expendible loran-based drifting buoy

Abstract

What could very easily be the oldest form of Oceanographic Instrumentation, a bottle with a note in it, has now been been brought up to date with a new Loran Based Lagrangian Drifter. The needs for this sort of system are many and varied. Everything from oil spill tracking, life raft drift prediction, effluent discharge and distribution tracking, and general oceanographic current studies are all addressed by this buoy. The construction of this buoy is discussed from its two styles of drogues (surface and deep), its kevlar hull and steel instrument bay to its low power Loran receiver and high power BF or VHF transmitters. This buoy differs from most drifting buoys in that rather than acting as a simple beacon and having the receiving station have the task of triangulating the location, it takes fixes on its location and retains that information in its own memory which can later be transmitted. This buoy has a positional accuracy approaching 100 feet, and can acquire fixes as often as every 15 minutes. Both of these parameters are far superior to other techniques presently in use.