Editing Lagrangian Drifter

[[Category:technology]]

Status: Contents not yet checked by product owner

== Description  (extern) ==
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). <gallery mode="packed-hover">
File:Lagrangian Drifter 2.jpg|Langrangian drifter
File:Lagrangian Drifter 1.jpg|Langrangian drifter in the field
</gallery>

== Measurement Parameters  (extern) ==
{| class="wikitable"
!SENSOR PARAMETER
!MANUFACTURER
!MODEL
!INTERFACE
!UNIT
!RANGE
!ACCURACY
!Registry UUID
|-
|DATE
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|TIME
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|LATITUDE
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|LONGITUDE
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|AIR TEMPERATURE
|Bosh
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|WATER TEMPERATURE
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|ATMOSPERIC PRESSURE
|Bosh
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|}

== Technical Requirements for Operators (extern) ==

=== Where to install the instrument on the ship? ===
Lagrangian Drifters are dropped over board underway sailing.

=== What power supply does the instrument require? ===
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? ===
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 ===
The drifter is water proof up to a water depth of approx. 1 m

=== What maintenance does the instrument require? ===
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? ===
Data will be automatically transferred via satellite on a predefined schedule e.g. every 5 minutes.

=== Prototypes ===
How many prototypes will be available for testing by operators by end of 2024? How many will be available by end of 2025?
{| class="wikitable"
!
!2024
!2025
|-
|Version 1
|30
|tbd
|-
|Version 2
|9
|tbd
|}

{| class="wikitable"
|+
!
!Prototype #
!Available for testing
!Start date
!End date
!Maximal usage time
|-
|Version 1
|1 - 30
|Yes
|Jun. 2024
|Dec. 2024
|150 days
|-
|Version 2
|1 - 9
|Yes
|Jun. 2024
|Dec. 2024
|tbd
|}

=== Costs ===
Cost of material for version 1 is approx. 300 Euro and for version 2 approx. 600 Euro

== Technichal Details ==
Will follow soon!

== Collaboration(s) ==
We started talking to two companies at the moment (Helzel Messtechnik and Sea & Sun)

== Use Case(s) involvement ==
Solely [[Use Case 4 - Sailors]]

== Development status ==

=== [[Technology Readiness Level]] ===
TRL 7

=== Expected date for market readiness ===

=== Commercial availability ===
Other Lagrangian drifters are available on the market, most of these are Version 1 type drifters and not environmentally friendly (one exception). Version two drifters are of very limited availability at significant costs.

=== Autonomous operation ===
Lagrangian Drifters are fully autonomous after deployment.

=== OSBK Interface ===
An OSBK interface has not been installed yet, as the boards are not available yet (27.08.2024). 

=== Up-scaling ===

== Data ==

=== Data transmission ===

=== Data handling ===

=== Data visualisation ===

=== Data business models ===

=== O2A Registry UUI ===

== How to install? ==

== How to operate? ==

== How to calibrate? ==

== Further details ==
 Product Owners: Ruben Carrasco, Jochen Horstmann, Alejandro Ordóñez, Michael Streßer (HEREON)