Publication
A Sound Projector for Acoustic Tomography and Global Ocean Monitoring, Andrey K. Morozov and Douglas C. Webb, IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 28, NO. 2, APRIL 2003
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New acoustic projector design capable of swept-frequency output under digital control.
Available as an integrated package including projector, signal generator, amplifier, microprocessor controller, and batteries. Available as a transceiver modification, which integrated with 4-channel acoustic STAR receiver (SCRIPPS), included a hybrid Rubidium low consumption clock and underwater acoustic navigation.
Intended for long-term moored applications in depths to 6000m.
The organ-pipe projector is not gas compensated, and has unlimited operating depth.
Suitable for acoustic tomography, RAFOS, and other applications.
- Frequency range: Frequency sweep, 200-300Hz; RAFOS sweep; CW signals 200-300Hz
- Max SPL: 195 dB re 1 micropascal at 1 m, efficiency 50%
- Directivity index: 3 dB in horizontal direction
- Projector: Micro-controller tunable “Organ-Pipe” with a symmetrical Tonpliz transducer, free flooded, 36 cm diameter
- Controller: 32 bit Motorola MC68CK338 micro-controller. Programmable via external SAIL connector. Integrated with 4-channel STAR receiver system (SCRIPPS) with the hybrid Rubidium low power clock and underwater acoustic navigation. Long term stability: 3 ms for 1 year.
- Batteries: Alkaline "D" cell assembly
- Endurance: 3000 transmissions
- Maximum operating depth: 6000 m for electronic housing, operating depth for projector unlimited
- Material: Aluminum 6061-T6, End-caps hard anodized
- Weight: 1000 kg
Seneca Lake Sonar Test Facility Results
200-300 Hz sweep signal transmitted from RV Point Sur to Pioneer Seamount receiver 11.09.2001
Map of the experiment
Spectrogram of a swept frequency source from the Pioneer Seamount receiver, distance 540km
Ray trajectories from RV Point Sur to Pioneer Seamount receiver
During February 2002- July 2003 the source was deployed near Guadeloupe, by IFM, Kiel, Germany as part of CLIVAR deep thermohaline transport array or MOVE program (Meridional Overturning Variability Experiment), and then after recovery again during 2004/2005 and 2005/2006 years
During R/V Point SUR voyage October 26 2002 the projector was deployed on the Hoke Seamount (depth 700 m) and successfully worked till October 2004. The sound source emitted at 06:00 am each day RAFOS signal and each forth day from the day of deployment at 00:00, 04:00, 08:00, 12:00, 16:00, 20:00 swept frequency signal. The spectrogram and correlation function of the signal receiving at the distance 700 km by single omni-direction hydrophone is shown below. On the spectroigram one can see whale's sounds at the beginning of record.
October 2007 Sound source was successfully recovered by Atlantis crew and the Alvin group
NPAL04 Long-Range Propagation Experiment: SPICE04 Pacific Ocean May 2004 –May 2005
225-325 Hz sweep signal transmitted from the depth 3000 m during SPICE04 experiment
- Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego
- US Naval Postgraduate School, Monterey
- Institut für Meereskunde (IFM), University of Kiel, Germany
- Institut Francais de Recherche pour L’Exloitation de la Mer (IFREMER), France
Nansen Environmental and Remote Sensing Center, Norway
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