Lagrangian Drifter
Status: Contents not yet checked by product owner
Description
[edit | edit source]The Lagrangian Drifters were designed and built at Helmholtz-Zentrum Hereon to follow the upper surface flow (approx. 50 cm). The main body of the Lagrangian Drifters consists of a 11 cm x 19 cm long tube with a flotation ring at the top. It is attached to a drogue of 35 cm in both length and diameter through a flexible cord within a distance of 10 cm to the tube. When deployed about 5 cm of the tube protrude from the water surface, resulting in a ratio of drag area inside to drag area outside the water of > 20. The tube contains a battery pack and an electronic board, which acquires and reports the collected data via a global satellite network in near real time. Two versions are available of which the simple version only reports date, time and position, at a predefined time interval (e.g. every 5 minutes), which enables to estimate surface current direction and speed. The version 2 measures in addition water temperature, air temperature and atmospheric pressure and can easily be equipped with additional sensors (e.g. salinity).
-
Lagrangian Drifter -
Lagranigian Drifter in the field
Measurement Parameters
[edit | edit source]| SENSOR PARAMETER | MANUFACTURER | MODEL | INTERFACE | UNIT | RANGE | ACCURACY | Registry UUID |
|---|---|---|---|---|---|---|---|
| DATE | |||||||
| TIME | |||||||
| LATITUDE | |||||||
| LONGITUDE | |||||||
| AIR TEMPERATURE | Bosh | ||||||
| WATER TEMPERATURE | |||||||
| ATMOSPERIC PRESSURE | Bosh |
Technical Requirements for Operators
[edit | edit source]Where to install the instrument on the ship?
[edit | edit source]Lagrangian Drifters are dropped over board underway sailing.
What power supply does the instrument require?
[edit | edit source]The drifter is powered by 4 x 1.5V D-cell batteries. The power consumption for Version 1 is approx. 20 mW and for Version 2 approx. 30 mW.
What is the size of the instrument?
[edit | edit source]The size of the main body is 23 x 19 x 19 cm, the drifters underwater sail has a size of 35 x 35 x 35 cm and can be folded to a sheet 35 x 35 x 0.5 cm.
Water proofness
[edit | edit source]The drifter is water proof up to a water depth of approx. 1 m
What maintenance does the instrument require?
[edit | edit source]Lagrangian Drifters are typically not recovered. However in case they are recovered they should be cleaned, batteries need to be replaced and test of all sensors should be undertaken.
How will data be transferred?
[edit | edit source]Data will be automatically transferred via satellite on a predefined schedule e.g. every 5 minutes.
Costs
[edit | edit source]Upon request by commercial manufacturer Marine Science and Technology
Technichal Details
[edit | edit source]Will follow soon!
Development status
[edit | edit source]TRL 7
Commercial availability
[edit | edit source]Contact person: Jan Widera
Autonomous operation
[edit | edit source]Lagrangian Drifters are fully autonomous after deployment.
Data
[edit | edit source]Data transmission
[edit | edit source]Data visualisation
[edit | edit source]How to install?
[edit | edit source]How to operate?
[edit | edit source]How to calibrate?
[edit | edit source]Further details
[edit | edit source]Product experts: Ruben Carrasco, Jochen Horstmann, Alejandro Ordóñez, Michael Streßer (HEREON), Jan Widera