From 16 September to 20 October 2020, three members of Ifremer's Indian Ocean delegation will visit the Europa Island in the Scattered Islands as part of the IOT project. The objectives of this mission are:
- to deploy the reception stations (an improved version of those set up for the "pIOT" project),
- install and test the LoRa network for proper operation,
- carry out bathymetry and photogrammetry measurements on predefined zones of interest for marine turtles using the USV autonomous board.
The island of Europa, like several other study sites of the IOT project, corresponds to a so-called “remote” site, i.e. without internet access or with a very limited and expensive satellite connection. In order to minimise the use of this satellite connection, Ifremer has worked on the development of a hybrid network based on LoRa.
Indeed, thanks to the LoRa network, the various receiving stations positioned all around the lagoon (where the juvenile sea turtles are present) will collect the data emitted by the turtle tags and will communicate this data between them in order to enable the geolocation of the tags and therefore of the turtles but also with the so-called "mother" station which will be located at the TAAF scientific base on the island. The role of this "mother" station will be to collect all the data re-transmitted by the lagoon's reception stations before transferring all the data to two separate servers, including a LoRaWan server.
For this 35-day mission, no less than 820 kilos of equipment were sent to Europa thanks to the French Navy's multi-mission ship "Champlain" and the military light tactical transport aircraft "Casa", with the support of the Armed Forces in the Southern Zone of the Indian Ocean (FAZSOI) and the French Southern and Antarctic Territories (TAAF).
Departure for Europa Island :
On September 16 2020, three members of the Ifremer team boarded the Casa to Europa Island in the Scattered Islands district for the first deployment of the project.
The objectives of this 35-day mission are:
- removing the reception stations of the "pIOT" pilot project and the deployment of four reception stations that will make it possible, on the one hand, to receive the signals sent by the turtle tags and, on the other hand, to transfer the data collected in this way to a secure server,
- installation of the LoRa network and the satellite system for data reception and transmission,
- characterisation of the LoRa radio channel on the water surface and validation of the good transmission and reception of messages in the lagoon and particularly in the difficult to access areas of the mangrove,
- the realization of bathymetric and photographic surveys of the bottoms for the development of photogrammetry of the areas of interest for the turtles,
- the tagging of 2 to 3 juvenile turtles in order to test and validate the robustness of the mechanical design and the on-board algorithms in an open environment and in real conditions. Once the system has been validated during this mission, a second tagging mission will take place in 2021 on a larger number of turtles (7 to 8 individuals), this time with the objective of using the dive data.
 Technique for creating a three-dimensional virtual image of a real object from numerous photographs and algorithms