Estimation of Directional Wave Spectra from an Autonomous Underwater Vehicle (AUV)
Abstract
Directional wave energy and wave spectra play an important role in the physical processes associated with the ocean environment. Determining these directional wave characteristics is a fairly arduous task. An Autonomous Underwater Vehicle (AUV) provides a suitable platform for making in-situ measurements in the ocean environment. Small AUVs can typically cover a 3-5 mile square region at a speed of 3-4 knots, allowing for the survey of the water column over a substantial range. Further, an AUV is much more versatile than the traditional bottom-mounted ADCPs, suspended current meters or drifting buoys in so much as the sensor (the AUV) is mobile and can be programmed to collect data in any desired area vice having to locate the sensors, recover them, transit and re-deploy. In this paper we examine the potential of an AUV to be used as a platform for making directional wave spectrum measurements, with particular reference to the Naval Postgraduate School's PHOENIX AUV. We show that by using relative velocity measurements from a SONTEK Acoustic Doppler Velocimeter (ADV), groundreferenced velocity measurements from a RDI Navigator Doppler Velocity Log (DVL), vehicle motion data from a Systron-Donner Motion Pak and employing a Maximum Entropy Method (MEM) the wave directional spectra can be found. The methodology used to determine the spectra, the corrections that are required to account for the Doppler shift due to the moving vehicle and the results obtained from data collected during AUVFEST 98 and experimental missions in Monterey Bay will be discussed and analyzed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA436031
Entities
People
- Anthony J. Healey
- Jeffrey S. Riedel
Organizations
- Naval Postgraduate School