Applied Ocean Physics and Engineering (AOP&E)

Permanent URI for this collection

https://hdl.handle.net/1912/10

The Department is a major center for research in fluid mechanics, coastal processes, ocean mixing, acoustics, air-sea interaction, deep submergence, ocean systems and moorings, remote sensing, robotics, certain biological processes, image processing, signal processing and estimation, control theory, and the dynamics of ocean cables.

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Browsing Applied Ocean Physics and Engineering (AOP&E) by Subject "Acoustic"
  • Article
    Closed‐loop one‐way‐travel‐time navigation using low‐grade odometry for autonomous underwater vehicles
    (John Wiley & Sons, 2017-09-07) Claus, Brian ; Kepper, James ; Suman, Stefano ; Kinsey, James C.
    This paper extends the progress of single beacon one‐way‐travel‐time (OWTT) range measurements for constraining XY position for autonomous underwater vehicles (AUV). Traditional navigation algorithms have used OWTT measurements to constrain an inertial navigation system aided by a Doppler Velocity Log (DVL). These methodologies limit AUV applications to where DVL bottom‐lock is available as well as the necessity for expensive strap‐down sensors, such as the DVL. Thus, deep water, mid‐water column research has mostly been left untouched, and vehicles that need expensive strap‐down sensors restrict the possibility of using multiple AUVs to explore a certain area. This work presents a solution for accurate navigation and localization using a vehicle's odometry determined by its dynamic model velocity and constrained by OWTT range measurements from a topside source beacon as well as other AUVs operating in proximity. We present a comparison of two navigation algorithms: an Extended Kalman Filter (EKF) and a Particle Filter(PF). Both of these algorithms also incorporate a water velocity bias estimator that further enhances the navigation accuracy and localization. Closed‐loop online field results on local waters as well as a real‐time implementation of two days field trials operating in Monterey Bay, California during the Keck Institute for Space Studies oceanographic research project prove the accuracy of this methodology with a root mean square error on the order of tens of meters compared to GPS position over a distance traveled of multiple kilometers.
  • Technical Report
    High continuous bandwidth multichannel acquisition system
    (Woods Hole Oceanographic Institution, 1991-06) von der Heydt, Keith
    Multichannel data acquisition has been a keystone of 7 ONR sponsored Arctic acoustic research programs conducted jointly by WHOI and MIT investigators from 1978 through 1989. This report describes the status and capability of the most recent system developed at WHOI for the purpose of acquiring digital data from up to 64 channels at sampling rates up to 20 kH per channel with data bandwidth to 5120 Hz. ONR funded the development of and use of this system and its prototye for 2 Arctic field experiments, PRUDEX 87 and CEAREX 89. It was most recently use during the Heard Island Feasibility Experiment in February 1991. Of note are the auto-gain ranging capabilty offering a dynamic measurement range of greater than 120 dB, the continuous storage capability of up to 200,000 samples per second to a Small Computer System Interface (SCSI) device, typically optical disk, and easy expandability with additional identical chanels connected in parallel.
  • Article
    Navigational infrastructure at the East Pacific Rise 9°50′N area following the 2005–2006 eruption : seafloor benchmarks and near-bottom multibeam surveys
    (American Geophysical Union, 2008-11-06) Soule, Samuel A. ; Ferrini, Vicki L. ; Kinsey, James C. ; Fornari, Daniel J. ; Sellers, Cynthia J. ; White, Scott M. ; Von Damm, Karen L. ; Carbotte, Suzanne M.
    Four seafloor benchmarks were deployed with ROV Jason2 at frequently visited areas along the northern East Pacific Rise (NEPR) ridge crest near 9°50′N, within the Ridge2000 EPR integrated study site (ISS) bull's eye. When used in concert with established deep-ocean acoustic positioning techniques, these benchmarks provide navigational infrastructure to facilitate the integration of near-bottom data at this site by allowing efficient and quantitative coregistration of data and observations collected on multiple dives and over multiple cruises. High-resolution, near-bottom multibeam bathymetric surveys also were conducted along and across the ridge crest to provide a morphological and geological context for the benchmark areas. We describe the navigation and data processing techniques used to constrain the benchmark positions and outline operational details to effectively use benchmarks at this and other deep-ocean sites where multidisciplinary time series studies are conducted. The well-constrained positions of the benchmarks provide a consistent geospatial framework that can be used to limit navigational uncertainties during seafloor sampling and mapping programs and enable accurate spatial coregistration and integration of observations. These data are important to test a range of multidisciplinary hypotheses that seek to link geological, chemical, and biological processes associated with crustal accretion and energy transfer from the mantle to the hydrosphere at mid-ocean ridges.