APL-UW Home

Jobs
About
Campus Map
Contact
Privacy
Intranet

David Dall'Osto

Senior Research Scientist/Engineer

Email

dallosto@apl.washington.edu

Phone

206-221-5085

Department Affiliation

Acoustics

Education

B.S. Mechanical Engineering, Vanderbilt University, 2006

M.S. Mechanical Engineering, University of Washington, 2009

Ph.D. Mechanical Engineering, University of Washington, 2013

Publications

2000-present and while at APL-UW

Physical effects of sound exposure from underwater explosions on Pacific sardines (Sardinops sagax)

Dahl, P.H., A.K. Jenkins, B. Casper, S.E. Kotecki, V. Bowman, C. Boerger, D.R. Dall'Osto, M.A. Babina, and A.N. Popper, "Physical effects of sound exposure from underwater explosions on Pacific sardines (Sardinops sagax)," J. Acoust. Soc. Am., 147, 2383-2395, doi:10.1121/10.0001064, 2020.

More Info

20 Apr 2020

Explosions from activities such as construction, demolition, and military activities are increasingly encountered in the underwater soundscape. However, there are few scientifically rigorous data on the effects of underwater explosions on aquatic animals, including fishes. Thus, there is a need for data on potential effects on fishes collected simultaneously with data on the received signal characteristics that result in those effects. To better understand potential physical effects on fishes, Pacific sardines (Sardinops sagax) were placed in cages at mid-depth at distances of 18 to 246 m from a single mid-depth detonation of C4 explosive (4.66 kg net explosive weight). The experimental site was located in the coastal ocean with a consistent depth of approximately 19.5 m. Following exposure, potential correlations between blast acoustics and observed physical effects were examined. Acoustic metrics were calculated as a function of range, including peak pressure, sound exposure level, and integrated pressure over time. Primary effects related to exposure were damage to the swim bladder and kidney. Interestingly, the relative frequency of these two injuries displayed a non-monotonic dependence with range from the explosion in relatively shallow water. A plausible explanation connecting swim bladder expansion with negative pressure as influenced by bottom reflection is proposed.

Estimation of seabed properties and range from vector acoustic observations of underwater ship noise

Dahl, P.H., and D.R. Dall'Osto, "Estimation of seabed properties and range from vector acoustic observations of underwater ship noise," J. Acoust. Soc. Am., 147, EL345, doi:10.1121/10.0001089, 2020.

More Info

17 Apr 2020

The Intensity Vector Autonomous Recorder (IVAR) simultaneously measures acoustic particle velocity and pressure. IVAR was deployed during the 2017 Seabed Characterization Experiment (SBCEX) with the primary objective to study sound propagation in fine-grained, muddy sediments. In this study a Bayesian inversion framework is applied to ship underwater noise recorded by IVAR. The data are relative phase of pressure and vertical particle velocity, a quantity that is independent of the ship noise source spectrum. Inversion estimates for the sediment layer and underlying basement properties are in agreement with other reports from SBCEX.

Vector acoustic analysis of time-separated modal arrivals from explosive sound sources during the 2017 Seabed Characterization Experiment

Dahl, P.H., and D.R. Dall'Osto, "Vector acoustic analysis of time-separated modal arrivals from explosive sound sources during the 2017 Seabed Characterization Experiment," IEEE J. Ocean. Eng., 45, 131-143, doi:10.1109/JOE.2019.2902500, 2020.

More Info

1 Jan 2020

The Intensity Vector Autonomous Recorder (IVAR) is a system that records four coherent channels of acoustic data continuously: one channel for acoustic pressure and three channels associated with a triaxial accelerometer from which acoustic particle velocity is obtained. IVAR recorded the vector acoustic field in broadband signals originating from Signal, Underwater Sound (SUS) (Mk-64) charges deployed at 5–13-km range from the fixed IVAR site (mean depth 74.4 m) as part of the 2017 Seabed Characterization Experiment (SBCEX) designed to study the acoustics of fine-grained muddy sediments. Sufficient geometric dispersion at these ranges permitted unambiguous identification of up to four modes as a function of frequency for frequencies less than 80 Hz. From time–frequency analysis of the dispersed arrivals, a single mode (n) and single-frequency (fi) properties are identified at peaks in the narrowband scalar field, with time dependence corresponding to mode group speed. At these time–frequency addresses, four quantities derived from the vector acoustic measurements are formed by coherent combination of pressure and velocity channels: first, modal phase speed; second, circularity, a measure of the normalized curl of active intensity; third, depth-dependent mode speed of energy; and fourth, vertical component of reactive intensity normalized by scalar intensity. A means to compute these quantities theoretically is provided, and a comparison of model results based on a notional geoacoustic representation for the SBCEX experimental area consisting of a single low-speed mud layer over a half-space area versus a Pekeris representation based on the same half-space shows a striking difference, with the field observations also clearly at variance with the Pekeris representation. A fundamental property of mode 2, observed at the IVAR location, is a change in sign for circularity and vertical reactive intensity near 37 Hz that is posited as a constraint observation for mode 2 that must be exhibited by any geoacoustic model that includes a low-speed mudlike layer applied to this location.

More Publications

Inventions

Acoustic Intensity Sensor Using MEMS Triaxial Accelerometer and MEMS Microphone

Record of Invention Number: 48987

David Dall'Osto, Peter Dahl

Disclosure

30 Jun 2020

Automatic Implementation of NOAA Marine Mammal Guidelines

Record of Invention Number: 48478

Peter Dahl, David Dall'Osto

Disclosure

13 Nov 2018

Airborne Acoustic Particle Motion Sound Meter

Record of Invention Number: 48135

David Dall'Osto, Peter Dahl

Disclosure

1 Aug 2017

More Inventions

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
Close

 

Close