June 2013
Firmware 2.2 for the Acousonde 3A and 3B supports high-time-resolution accelerometry, raising the maximum accelerometer sample rate from 20 to 800 Hz! The new firmware also raises the maximum compass sample rate from 20 to 40 Hz, the hardware limit. For Acousonde 3B models, the firmware enables sampling of the light-level channel built into all 3B units. See detailed release notes here.

The new firmware and updated commanding app provide the following sampling programs on the Acousonde 3B. Due to the Acousonde 3A's lack of a light sensor, 3A models will not sample light level but will instead sample temperature more often for rates faster than 1 Hz.

  • 5-s period all aux channels (compass, accel, depth, temperature, light)
  • 1 Hz all aux channels
  • 5 Hz all aux channels, except depth/temp/light sampled at 1 Hz
  • 10 Hz all aux channels, except depth/temp/light sampled at 1 Hz
  • 10 Hz all aux channels, except temp/light sampled at 5 Hz
  • 100 Hz accelerometer; 10 Hz compass/depth; 5 Hz temp/light
  • 400 Hz accelerometer; 20 Hz compass; 10 Hz depth; 5 Hz temp/light
  • 800 Hz accelerometer; 40 Hz compass; 10 Hz depth; 5 Hz temp/light

Note that, although accelerometer channels are sampled simultaneously, compass channels are not. See this FAQ entry detailing sampling behavior for auxiliary channels. Please also see this clarification regarding the capabilities of the 3B light sensor.

Customers may update firmware themselves by following these instructions; alternately, US customers are welcome to return units directly to Greeneridge Sciences for firmware update at no charge. International customers who wish to return units for firmware update should contact Cetacean Research Technology, the Acousonde distributor. Contact information may be found here..

August 2012
The Acousonde 3B design has demonstrated an attachment life of ∼2 days, carried over a distance of ∼120 km (∼65 nautical miles) by a free-ranging male tusk-bearing narwhal in East Greenland. The test, conducted by Mads Peter Heide-Jørgensen with the Greenland Institute of Natural Resources, relied on the Acousonde 3B's standard configuration of four 3-cm silicone suction cups secured by hand to a temporarily captive wild narwhal. An added satellite transmitter and extra flotation allowed the tag to be located and retrieved after being carried such a distance.

User-added flotation and satellite transmitter on the trailing end of an Acousonde 3B. Photo by Mads Peter Heide-Jørgensen, used with permission.

Acousonde 3B attached by hand to a temporarily captive male tusk-bearing narwhal in East Greenland using the 3B's standard suction-cup configuration. Photo by Mads Peter Heide-Jørgensen, used with permission.

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.