Keeping track of wildlife with Metop
Satellites can carry out multiple jobs by carrying different instruments and transponders on board. Metop is one of a range of polar-orbiting satellites used by the Argos system to relay radio signals that can help study a huge range of phenomena.
The Argos Data Collection and location System began as a way of collecting weather data and information about the oceans. It was initiated by the French space agency, le Centre national d’études spatiales (CNES), along with the US National Oceanic and Atmospheric Administration (NOAA) and US space agency, NASA. Over time, new ways of using the transmitters have contributed to a huge range of research from atmospheric science to zoology.
There over 21,000 Argos transmitters dotted around some of the most difficult to reach places all over the world. They send out radio signals that are picked up by satellites and transmitted back to Earth as part of the satellite’s normal orbital routine.
The Argos Advanced Data Collection System (A-DCS) instrument on board Metop can send a signal to the Argos transmitter to confirm it has received some data, and sends data to a ground station once it is in the right part of its orbit.
Argos collects the information from the different ground stations and gets it ready for its users at processing facilities in France and the United States. The information can then be sent out to the many projects and many thousands of scientists who need it.
Many of the Argos transmitters are attached to buoys, floating in the ocean, but some are attached to living creatures. This means scientists can track individuals from different species – some endangered – in the most remote parts of the world.
Several different teams of scientists have used Argos transmitters to find out more about the behaviour of endangered sea turtles. The seaturtle.org project tracked a turtle crossing the Pacific Ocean, the first time an animal had been tracked across the entire ocean.
By attaching transmitters to just over two hundred loggerhead turtles, another team of scientists found out how the turtles behaved in different water temperatures, where they ate, and even how fast they swam. The researchers particularly wanted to find out where juvenile turtles were most often found, to try to stop them being caught accidentally by fishermen.
Bird migrations and feeding patterns have also been tracked. One recent project looked at the migration patterns of the Oriental Honey-Buzzard. This Asian bird spends summer in Siberia, China, Mongolia, Korea or Japan, but flies south for the winter. Researchers were particularly interested in how the birds managed to cross large areas of water travelling between Japan and southeast Asia. They used the Argos tracking system to compare the movement of the birds with the local weather conditions over the sea, discovering that during autumn there are strong thermals over the South China Sea that allow the birds to soar and glide. The researchers even posted the movements of the birds in almost real time online.
Satellite tagging was also a vital part of the Census of Marine Life project.
An amazing range of animals has been tracked using the Argos system, including such contrasting creatures as jellyfish and elephants. The tags attached to buoys at sea can also deliver information about marine pollution. Argos System produces a regular update of new experiments using the satellite system in an online magazine, where you can read more about the vast number of projects being carried out.