News!

January 27, 2012

An Acousonde 3A has successfully sustained a 464-kHz acoustic sample rate in two tests powered by its standard lithium A-cell. In the first test at room temperature, recording lasted 34 hours, filling 114 GB of onboard storage before the battery gave out. In the second test at an average of 7.5°C, recording lasted 38 hours, filling all 128 GB available.

Until now high-frequency-enabled Acousonde units could not reach their expected maximum sample rate of 232 kHz due to firmware limitations. Firmware Version 2.1 makes use of special-purpose hardware built into every Acousonde to reduce power consumption by as much as 50% and to reach — and exceed by double! — the originally-expected maximum sample rate.

Even Acousonde units without the high-frequency option can benefit from Version 2.1's substantial reduction in power consumption. New units (August 2011 or after) with the high-frequency option can sustain the 464-kHz sample rate, while older units with the high-frequency option will sustain 232-kHz sampling.

A beta-test release of the new firmware is available to interested Acousonde users.

May 18, 2011

The first deployment of an Acousonde™ 3B with an animal took place 11 May 2011. Cascadia Research, in collaboration with the NOAA Pacific Islands Fisheries Science Center and Greeneridge Sciences, Inc., placed the tag on a pantropical spotted dolphin off the coast of the Big Island of Hawai`i. The Office of Naval Research provided support for the effort.

From the beginning, development of the Acousonde 3B centered on potential applications with small odontocetes, emphasizing small size, hydrodynamic overall shape including float, and low profile. Until this deployment, however, these design ideas had remained untested.

We are happy to report that, even on this relatively small and fast-moving animal, the tag remained attached for 12 hours, 18 minutes. It gathered acoustic data using its high-frequency hydrophone at 116 kHz sample rate until the primary storage card filled (a total of 8 hours, 22 minutes on the animal in addition to 50 minutes pre-deployment). Auxiliary data gathered consisted of dive depth and tag temperature at 10 Hz, and 3D tilt and 3D compass at 20 Hz, sampled continuously until the tag was manually stopped after its recovery two days later.

Going forward, we plan to improve the suction-cup system to extend attachment time, while implementing software support for greater acoustic recording capacity (please see the release notes for the current software status).

The following three photographs, reposted here from Cascadia's web log of their May 2011 Hawai`i Island field work, were taken under NMFS Scientific Research Permit No. 731-1774.

Attempting to deploy the Acousonde 3B on a pantropical spotted dolphin. Photo by Robin Baird, used with permission.

Acousonde 3B attached to a pantropical spotted dolphin with suction cups. Photo by Robin Baird, used with permission.

An Acousonde 3A, equipped with a float designed and built by Cetacean Research Technology, was also deployed during the field work. This unit was attached to a short-finned pilot whale with suction cups on 6 May. Photo by Robin Baird, used with permission.

January 18, 2011

The Acousonde™ 3B is formally announced. Please see the release announcement!

January 16, 2009

The Acousonde™ 3A is formally announced.