FLIP's Research Experience

FLIP's stability, 300-foot draft, and low acoustic noise levels have made it uniquely suitable for a wide variety of research experiments.

Hydrophones can be positioned at a variety of depths for listening to acoustic signals, and the same applies for other instrumentation such as pressure sensors for measuring wave heights, tilt and depth of FLIP, or temperature sensors for measuring thermal structure in the ocean.

In order to study the horizontal extent of thermal variations in the ocean, three booms can be extended so that temperature sensors can be lowered simultaneously at known distances from one another.

Density variations in the upper levels can be studied with high resolution Doppler sonar. Meteorological instruments mounted on a vertical mast that can move up and down at the end of a boom make it possible to make measurements immediately above the sea surface. FLIP’s deep-sea winch can lower instrumentation packages to a depth of 4,000 meters. Booms below the waterline can also be mounted on the hull for obtaining horizontal separation of sensors.

The early demonstration of FLIP's unique capabilities as an ocean-going measurement platform with very low motions has led to its use for many other programs. A list of papers published as a result of the use of FLIP demonstrate the versatility of FLIP.

Research conducted on FLIP has included studies of:

  • the relation of temperature variations in the ocean to fluctuations in intensity and direction of sound waves;
  • waves generated from storms in the South Pacific, for which FLIP was stationed between Hawaii and Alaska;
  • turbulence and thermal structure of the ocean;
  • amplitude and directionality of internal waves;
  • energy transfer between the ocean and atmosphere in which wind velocity, humidity, and temperature profiles immediately above the ocean surface were measured;
  • ambient noise intensity and direction using vertical hydrophone arrays suspended from FLIP and horizontal arrays (DIMUS) at the bottom of FLIP;
  • long-range sound propagation; variation in properties of the earth's crust, for which FLIP was used as a listening platform for explosive sound signals launched from four ships going away from FLIP in four different directions;
  • depths to which whales dive;
  • effects of pressure on sound attenuation;
  • scattering of sound from the sea surface and reverberation.