Bringing the Ocean to Society
10 Mar 2020
VLIZ develops robot to validate satellite measurements
Learn more about PANTHYR, the EurOcean's Member new robot system that autonomously monitors the sea.

Scientists use satellite data to gain better insight in algal blooms and sediment transport in coastal waters. Occasionally they have to check the accuracy of this data against measurements made at the spot - at the sea surface - and eventually correct for errors. Traditionally marine scientist undertake expeditions with a research vessel to measure the actual situation. Within the project Hypermaq, the (EurOcean Member) Flanders Marine Institute (VLIZ) developed an automated way of working and created the robot system PANTHYR. This robot is able to collect autonomously more data at sea than was ever possible. A follow-up project now aims at unrolling a network of these robots worldwide.

Satellites and their applications are common in our daily lives. Just think of the observations of weather and climate, GPS navigation, and watching TV over longer distances. Other types of satellites have applications in research. Some are equipped with hyperspectral sensors; devices that determine how much light from which wavelength the earth, the ocean and vegetation reflect. Next to measuring visible light, the sensors also measure near infrared and ultraviolet light (UV).

Scientists are thus able to observe the phytoplankton in seawater from space. These are single-celled algae and other small plant-like organisms that form the basis of the food web in the ocean. Phytoplankton has chlorophyll and other pigments that capture the incident light to conduct photosynthesis. The presence of these pigments in (sea) water changes the way in which the seawater reflects and absorbs sunlight. Measurements of different wavelengths of reflected light with allow scientists to determine the amounts of phytoplankton in the sea.

The hyperspectral measurements made by satellites have to be checked occasionally by the same type of measurements at sea level. For this purpose, VLIZ designed and developed the robot system PANTHYR that can perform these light measurements automatically at a fixed location at sea. The robot first calculates the position of the sun and then positions its sensors in the right direction and at the right height. Once in position, the robot performs a hyperspectral light measurement and takes photos to be able to check the collected data for deviations (due to clouds, birds flying past, etc.).

The first prototype of the robot system was created in 2018 and received the working title ‘James’. James underwent a number of successful field tests on ‘Acqua Alta’ - a measuring platform 20 kilometers off the coast of Venice - where the system is now permanently installed. Today, two years after the first prototype, VLIZ presents the final robot system.

With the help of PANTHYR, scientists are now able to collect more data for our coast and worldwide than ever before. In the near future, the Royal Belgian Institute of Natural Sciences (RBINS) will unroll a network of the robot system developed by VLIZ in the framework of the recently launched project ‘Waterhypernet’. With the collected data, space organizations such as ESA and NASA will be able to better validate their satellites.

VLIZ developed the robot ‘PANTHYR’ (Pan-and-Tilt Hyperspectral Radiometer System) within the Hypermaq project (Hyperspectral and multi-mission high resolution optical remote sensing or aquatic environments). The project is a collaboration between the Royal Belgian Institute of Natural Sciences (RBINS), UPMC, UGent, VLIZ, IAFE and SKLEC, and was funded by the Federal Science Policy (BELSPO) within the framework of the STEREO III program (SR/00/335). Over the next two years, VLIZ technicians will further adjust PANTHYR and provide additional applications within the follow-up project Aqualooks.

Link: https://odnature.naturalsciences.be/hypermaq/