Directional frequency and recording (DIFAR) sensors in seafloor recorders to locate calling bowhead whales during their fall migration
| Autor: | W. John Richardson, Robert G. Norman, Charles R. Greene, Miles W. McLennan, Trent L. McDonald, Ray S. Jakubczak |
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| Rok vydání: | 2004 |
| Předmět: |
Acoustics and Ultrasonics
Bioacoustics Arts and Humanities (miscellaneous) biology.animal Animals Sound Localization Balaena Underwater acoustic propagation biology Whale Whales Acoustics Bearing (navigation) biology.organism_classification Seafloor spreading Oceanography Chemical Industry Oil production Calibration Animal Migration Submarine pipeline Seasons Vocalization Animal Noise Geology Seismology |
| Zdroj: | The Journal of the Acoustical Society of America. 116:799-813 |
| ISSN: | 0001-4966 |
| Popis: | Bowhead whales, Balaena mysticetus, migrate west during fall approximately 10-75 km off the north coast of Alaska, passing the petroleum developments around Prudhoe Bay. Oil production operations on an artificial island 5 km offshore create sounds heard by some whales. As part of an effort to assess whether migrating whales deflect farther offshore at times with high industrial noise, an acoustical approach was selected for localizing calling whales. The technique incorporated DIFAR (directional frequency and recording) sonobuoy techniques. An array of 11 DASARs (directional autonomous seafloor acoustic recorders) was built and installed with unit-to-unit separation of 5 km. When two or more DASARs detected the same call, the whale location was determined from the bearing intersections. This article describes the acoustic methods used to determine the locations of the calling bowhead whales and shows the types and precision of the data acquired. Calibration transmissions at GPS-measured times and locations provided measures of the individual DASAR clock drift and directional orientation. The standard error of the bearing measurements at distances of 3-4 km was approximately 1.35 degrees after corrections for gain imbalance in the two directional sensors. During 23 days in 2002, 10,587 bowhead calls were detected and 8383 were localized. |
| Databáze: | OpenAIRE |
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