Instrumentation for passive and active acoustic cetacean-prey studies
Abstract
Here it is proposed to improve the active acoustic instrumentation available to PI Baumann-Pickering, other PIs at SIO as well as collaborators, and post-doctoral researchers, graduate, and undergraduate students working within various groups. It is intended to procure one mooring-based stationary active acoustic system using novel wideband technology to be added to a deep mooring. Proposed is the procurement of improved active acoustic instrumentation for integrated passive and active acoustic cetacean-prey studies. It is intended to obtain one ship-based mobile and one mooring-based stationary active acoustic system using novel wideband technology. This new method uses frequency modulated (sweep) signals instead of continuous frequency pulses. The improved system provides gradual frequency responses of targets and hence more detailed size classes and increased information on target species and angle of orientation. Additionally, for resolved single targets, this system allows for both high range resolution (using wide bandwidth) and long range (using long pulse duration) which used to be a compromise with recent systems. The ship-based active acoustic Simrad EK80 system is proposed to consist of a pole-mounted, four frequencies, mobile transducer array (MTA-4): 38, 70, 120, and 200 kHz. A computer and monitor unit captures the data transmitted via Ethernet from four wideband transceivers (WBT) in a rack. The mooring-based stationary active acoustic system will be integrated into a passive acoustic mooring (~4000 m water depth), holding a passive acoustic recorder (HARP) at ~800 m depth. It will be improved with a wideband autonomous transceiver (WBAT) and transducer with a nominal frequency of 70 kHz that is capable of sweeping from 55 to 90 kHz. Additionally, a conductivity-temperature-depth recorder with oxygen sensor (MicroCAT CTD, SBE 37SMP-ODO) will be installed at the same depth as the WBAT system to provide information about the oceanographic condition at depth. These new systems can a) be used in short- and long-term monitoring by including predator-prey models, leading to improved cetacean predictability and mitigation during naval exercises and b) shed light on the relationship of acoustic backscatter and ambient sound across time and space, which is relevant to the U.S. Navy sonar community. This abstract is publicly releasable.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141612547
Entities
People
- Simone Baumann-Pickering
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego