Lagrangian ambient noise drifter

The Defence Research Establishment Atlantic has carried out an experiment to study the relationship between ambient noise and oceanographic features in regions of pronounced oceanic currents, such as the Gulf Stream or its eddies, using a field of purpose built, long life drifting buoys developed and maintained at sea by Seimac Limited, of Dartmouth, Canada. These Lagrangian Ambient Noise Drifters (LANDs) comprise a drogued free floating buoy which employs telemetry over ARGOS satellites to report hourly measurements of the underwater ambient noise spectrum, as well as the surface wave energy spectrum, wind speed and direction, Global Positioning System geographic position, and water temperature at the sea surface and at the hydrophone. This paper presents the various aspects of the design of the LAND buoys, with particular emphasis on the techniques for measuring and processing the ambient noise and surface wave height data. Comparative data for these parameters are presented