Motion / Acceleration

Standard versions

The Thelma Biotel Acoustic Acceleration Transmitter (Acceltag) contains a 3-axis accelerometer similar to what you find in a smartphone. This transmitter can register gravity forces and acceleration in the x-, y and z directions with very high sensitivity. The most common, standard, versions of the acceltag is the tilt or level measurement version (outputs a simple 0-180 degree number), and the activity level measurement version (register fish activity and outputs a RMS ms-2m over a chosen sample period). The acceltag is avaliable down to 7.3 mm diameter size. As with our other sensors it is available in a variety of battery options for different power output settings and lifetimes.  

Behavioural signature capture

From the generic 3-axis acceleration measurements, the tag can for example register the tilt- and roll angle of the fish, as well as motion in the forward- and lateral directions. These key parameters reflects a broad range movement- and activity patterns of aquatic specimens that in turn can be used to study behavior and/or welfare. A key feature of the more advanced use of the Acceltag is the capability of detecting one or more motion signatures based on the raw data from the 3-axis accelerometer. The Acceltag has a powerful processing unit that can be programmed and adapted to the relevant specimen and movement patterns. Relevant movements include feeding- or spawning behavior, body tilt/orientation, rest- or activity level, comfort- or stress state and much more. The transmitter can for example be programmed to detect attacks against a prey, count how many times this movement signature is detected during a period of time, and transmit the stored number of detected movement signatures wirelessly. These methods is similar to the technology used in your smartwatch or excersize wristband which turns in the screen only when you are turning your arm to look at it. 

Such detection algorithms can be tailor made to your specific species and be developed in cooperation with usl. The learning should ideally be based on real data from controlled conditions where the relevant specimen is set up to log data directly from the desired motion pattern. In most cases the recording of actual bahaviour from an animal is not feasible, like spawning or mating behaviour which can not be triggered easily. To capture data which can be used to learn and compose a detector for the motion signature, a cabled sensor "tag" is normally used. The cable is plugged directly into the computer and captured data is backed up with video clips. This can be done at your facility directly, or we can do it here at our facility based on video you send us.

Pressure sensor integration

The acceleration/motion tag is also available in a version with pressure sensor. It is also produced down to 7.3 mm size and will then allow you to measure activity or behaviour signature recognition, as well as depth and temperature.

Motion transmitter technical data

  A-LP7  A-LP9  A-LP13
Length (low power version)  [mm] 23 26 30
Diameter [mm] 7.3  9  13
Weight in air [g] 2.6  4.5 6.5

Typical battery life [months]

(depends on transmit interval and measurement period)

12 20