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Pair-wise processing of spectrograms for localization of multiple broadband CW sources
- Proceeding of the IEEE Oceans ’05 Europe meeting
"... Abstract- A pair-wise processing algorithm has been developed to localize broadband sources in shallow water. A simple sparse hydrophone array with number of elements roughly equal to the maximum number of sources is used. The sources can be continuous-wave (i.e. no onset times), and no previous kno ..."
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Abstract- A pair-wise processing algorithm has been developed to localize broadband sources in shallow water. A simple sparse hydrophone array with number of elements roughly equal to the maximum number of sources is used. The sources can be continuous-wave (i.e. no onset times), and no previous knowledge of source signatures is required. The processor is spatially coherent and partially frequency coherent. Simulations show considerable improvement over conventional (i.e., frequency incoherent) matched field techniques under realistic noise conditions, with environmental mismatch and multiple sources. Spectrograms have been incorporated into the algorithm to make use of higher frequencies at greater ranges. Our work is motivated by the problem of localizing multiple singing humpback whales, and recordings of humpback whale song from the Pacific Missile Range Facility in Hawaii are being analyzed. I.
Source levels of social sounds in migrating humpback whales (Megaptera novaeangliae)
"... The source level of an animal sound is important in communication, since it affects the distance over which the sound is audible. Several measurements of source levels of whale sounds have been reported, but the accuracy of many is limited because the distance to the source and the acoustic transmi ..."
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The source level of an animal sound is important in communication, since it affects the distance over which the sound is audible. Several measurements of source levels of whale sounds have been reported, but the accuracy of many is limited because the distance to the source and the acoustic transmission loss were estimated rather than measured. This paper presents measurements of source levels of social sounds (surface-generated and vocal sounds) of humpback whales from a sample of 998 sounds recorded from 49 migrating humpback whale groups. Sources were localized using a wide baseline five hydrophone array and transmission loss was measured for the site. Social vocalization source levels were found to range from 123 to 183 dB re 1 lPa @ 1 m with a median of 158 dB re 1 lPa @ 1 m. Source levels of surface-generated social sounds ("breaches" and "slaps") were narrower in range (133 to 171 dB re 1 lPa @ 1 m) but slightly higher in level (median of 162 dB re 1 lPa @ 1 m) compared to vocalizations. The data suggest that group composition has an effect on group vocalization source levels in that singletons and mother-calf-singing escort groups tend to vocalize at higher levels compared to other group compositions.
Humpback Whale Song or Humpback Whale Sonar? A Reply to Au et al.
"... Abstract—Au and colleagues ’ arguments against the hypothesis that humpback whale songs function as long-range sonar are based on questionable assumptions rather than on empirical data. Like other echolocating mammals (e.g., bats), singing humpback whales: 1) localize targets in the absence of visua ..."
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Abstract—Au and colleagues ’ arguments against the hypothesis that humpback whale songs function as long-range sonar are based on questionable assumptions rather than on empirical data. Like other echolocating mammals (e.g., bats), singing humpback whales: 1) localize targets in the absence of visual information; 2) possess a highly innervated peripheral auditory system; and 3) modulate the temporal and spectral features of their sounds based on environmental conditions. The sonar equation is inadequate for determining whether humpback whale songs generate detectable echoes from other whales because it does not account for temporal variables that can strongly affect the detectability of echoes. In particular, the sonar equation ignores the fact that much of the noise encountered by singing humpback whales is spectrally and temporally predictable, and that audition in mammals is a dynamic and plastic process. Experiments are needed to test the hypothesis that singing humpback whales listen for and respond to echoes generated by their songs. Index Terms—Baleen whale, cetacean, environmentally-adaptive sonar, low-frequency sonar, mysticete.
Consultation by: Endangered Species Act Interagency Cooperation Division ofthe Office of Protected Resources, National Marine Fisheries Service Approved by:
, 2013
"... This biological opinion was prepared by NOAA's National Marine Fisheries Service (NMFS) Endangered ..."
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This biological opinion was prepared by NOAA's National Marine Fisheries Service (NMFS) Endangered
Consultation by: Endangered Species Division of the Office of Protected Resources, National
, 2011
"... mammals incidental to training on the Gulf of Alaska Temporary Maritime ..."
Consultation by:
, 2011
"... Section 7(a){2) of e Endangered Species Act (ESA) (16 U.S.C. 1531 et seq.) requires that each Federal agency shall ensure that any action authorized, funded, or carried out by such agency is not likely to jeopardize the continued existence of any endangered or threatened species or result in the des ..."
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Section 7(a){2) of e Endangered Species Act (ESA) (16 U.S.C. 1531 et seq.) requires that each Federal agency shall ensure that any action authorized, funded, or carried out by such agency is not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of critical habitat of such species. When the action of a Federal agency "may affect" a listed species or critical habitat that has been designated for such species, that agency is required to consult with either NOAA's National Marine Fisheries Service (NMFS) or the U.S. Fish and Wildlife Service, depending upon the listed resources that may be affected. Federal agencies are exempt from this general requirement if they have concluded that an action "may affect, but is not likely to adversely affect " endangered species, threatened species, or designated critical habitat and NMFS or the U.S. Fish and Wildlife Service concurs with that conclusion (50 CRF 402.l4{b)). For the actions described in this document, the action agencies are the United States Navy (Navy), which proposes to (1) conduct training on the Gulf of Alaska Temporary Maritime Activities Area (TMAA) and (2) NMFS ' Office of Protected Resources Pennits, Conservation, and Education Division (Pennits Division), which proposes to issue a Letter of Authorization would allow the Navy to "take " marine mammals incidental to those military readiness activities under the Marine Mammal Protection Act
