2023_programme: Seasonal and spatial dependencies in seabed decorrelation rates

• Session: 06. Marine sediment acoustics
  Organiser(s): Megan Ballard, Kevin Lee and Nick Chotiros
• Lecture: Seasonal and spatial dependencies in seabed decorrelation rates [invited]
  Paper ID: 2063
  Author(s): Venegas Gabriel R., Lyons Anthony P., Hare Jenna
  Presenter: Venegas Gabriel R.
  Abstract: In hydrodynamically and biologically active marine environments, the seabed can exhibit time-dependent changes in surface roughness, internal structure, and composition, where a small change in the seabed can result in significant ping-to-ping decorrelation. This non-stationarity can present challenges in change detection for synthetic aperture sonar, therefore knowledge of seabed decorrelation rate is important and warrants further study, particularly with respect to seasonal and spatial dependencies. In addition, seabed decorrelation rate measurements could be a sensitive and informative metric for long-term benthic ecosystem monitoring. To this end, a tripod equipped with a Simrad EK80 Wideband Acoustic Transceiver (WBAT) was deployed at two dynamic sites off the coast of New Hampshire, USA, over both winter and summer seasons. For each of the four five-month deployments, the WBAT acquired 50 pings of seafloor backscatter every hour from a 38 kHz, 70 kHz, and 200 kHz transducer. The transducers were positioned at a height of approximately 2 meters above the seafloor and were angled at 20 degrees grazing with respect to the local (nearly horizontal) seabed slope. The tripod was also equipped with a wave-sensing CTD, downward-looking stereo cameras, and forward-looking camera. Seasonal and spatial dependencies in seabed decorrelation rates will be discussed. [Work supported by the US Office of Naval Research under grant number N00014-19-1-2732]
• Corresponding author: Dr Gabriel R. Venegas
  Affiliation: University of New Hampshire
  Country: United States
  e-mail: