Johnson
Hansen D.
Johnson
Hansen D.
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Technical ReportAcoustic and oceanographic observations collected during the Nomans Island experiment in Spring 2017(Woods Hole Oceanographic Institution, 2020-07) Johnson, Hansen D. ; Newhall, Arthur E. ; Lin, Ying-Tsong ; Baumgartner, Mark F.The Woods Hole Oceanographic Institution (WHOI) has developed a digital acoustic monitoring (DMON) instrument and low-frequency detection and classification system (LFDCS) to detect and classify baleen whales in near real-time from autonomous platforms. This document provides a detailed description of the data, sensors, and research activities pertaining to the Nomans Island experiment, which was designed to evaluate the range-dependent accuracy of the DMON/LFDCS on mobile and fixed platforms. The experiment took place over a 4-week period (28 Feb to 31 Mar) in the spring of 2017 at a shallow (30m) site approximately 15 km Southwest of Martha’s Vineyard, USA. A DMON/LFDCS-equipped Slocum glider was deployed alongside an extant DMON/LFDCS moored buoy to provide the means to compare system performance between platforms. Vertical and horizontal hydrophone line arrays were deployed in the same area to facilitate call localization. A short transmission loss trial was conducted shortly after the array deployments. The Slocum glider and several sensors mounted to the arrays provided environmental data to characterize variability in water column structure and sound speed during the study period.
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ArticleAcoustic detection range of right whale upcalls identified in near-real time from a moored buoy and a Slocum glider(Acoustical Society of America, 2022-04-13) Johnson, Hansen D. ; Taggart, Christopher T. ; Newhall, Arthur E. ; Lin, Ying-Tsong ; Baumgartner, Mark F.The goal of this study was to characterize the detection range of a near real-time baleen whale detection system, the digital acoustic monitoring instrument/low-frequency detection and classification system (DMON/LFDCS), equipped on a Slocum glider and a moored buoy. As a reference, a hydrophone array was deployed alongside the glider and buoy at a shallow-water site southwest of Martha's Vineyard (Massachusetts, USA) over a four-week period in spring 2017. A call-by-call comparison between North Atlantic right whale upcalls localized with the array (n = 541) and those detected by the glider or buoy was used to estimate the detection function for each DMON/LFDCS platform. The probability of detection was influenced by range, ambient noise level, platform depth, detection process, review protocol, and calling rate. The conservative analysis of near real-time pitch tracks suggested that, under typical conditions, a 0.33 probability of detection of a single call occurred at 6.2 km for the buoy and 8.6–13.4 km for the glider (depending on glider depth), while a 0.10 probability of detection of a single call occurred at 14.4 m for the buoy and 22.6–27.5 km for the glider. Probability of detection is predicted to increase substantially at all ranges if more than one call is available for detection.