The IEEE Seventh Working Conference on Current Measurement Technology

Current and Wave Monitoring and Emerging Technologies

March 13-15 | Bahia Hotel | San Diego, CA, USA

  
     

An integrated method of obtaining absolute ocean velocity from a profiling free vehicle.

Ellyn T. Montgomery

Status: Accepted

MS 21, WHOI

Woods Hole , MA US
02543

Phone: (508) 289-2492
Email: emontgomery@whoi.edu

Co-Authors:
Kurt Polzin, WHOI

An instrument system to determine earth referenced ocean velocity accurately with high vertical resolution from a vertically profiling free vehicle is being developed. Three sensor systems are employed to complete the task of obtaining high quality velocity profiles from this vehicle.

An acoustic travel-time current meter with a specially configured sensor (Thwaites, in prep.) is employed to resolve fine scale velocity fluctuations relative to the profiler. The orientation of the vehicle is quantified using on-board accelerometers and a compass. Earth coordinate velocity relative to the vehicle is obtained by adjusting the acoustic data for instrument tilt and orientation. The oceanic velocity field is determined from the estimates of relative flow, acceleration and orientation using a model of the profiling
system's response to the relative flow.

The current meter derived estimate is uncertain at the largest vertical scales estimated. An electromagnetic field sensor (Sanford, 1971) modified for use in this application was used to constrain the velocity estimates over the entire depth of a profile. This estimate is uncertain to within a conductivity weighted mean. Thus a GPS receiver is used to determine the barotropic component of the oceanic flow field.

Design, testing and implementation issues of this system will be discussed.

Submitted on October 31, 2002