Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2012The Acoustic Doppler Current Profiler (ADCP) is a proven technology which is capable of measuring surface wave height and directional information, however it is
generally limited to rigid, bottom mounted applications which limit its capabilities
for measuring deep water waves. By employing an upward looking ADCP on a moving platform, such as an autonomous underwater vehicle or submerged
float, we show
that it is possible to remove the wave induced motion of the platform and accurately
measure surface ocean wave information.
The platform selected for testing was a REMUS-100 vehicle equipped with an
upward and downward looking ADCP and high accuracy Kearfott inertial navigation
unit. Additionally, a Microstrain 3DM-GX3-25 Attitude Heading Reference System
was tested as a low cost alternative to the Kearfott system. An experiment consisting
of multiple REMUS deployments was conducted near the Martha's Vineyard Coastal
Observatory (MVCO). The wave induced motion was measured by various inertial and
acoustic sensors and removed from the ADCP data record. The surface wave height
and mean directional estimates were compared against a Datawell MKIII directional
Waverider buoy and bottom mounted 1200 kHz upward looking ADCP at the MVCO.
Results demonstrate that the non-directional spectrum of wave height and the
mean wave direction as a function of frequency can be accurately measured from an
underway autonomous underwater vehicle in coastal depth waters using an ADCP.I would like the thank the U.S. Navy, Woods Hole Oceanographic Institute, and the Woods Hole Oceanographic Institute's "Access to the Sea" program for
sponsoring my education and research