Tartu Observatory develops new instruments for global remote sensing network

“The biggest problems with optical satellite remote sensing are that the satellite sensor can be calibrated at the optics laboratory only before the launch and that on-ground objects are measured through the atmosphere – anyone who has looked out of the airplane window or seen a bluish forest behind a large field should understand the problem,” said Joel Kuusk, Senior Research Fellow at Tartu Observatory’s Department of Remote Sensing.

This is why ground support measurements are required, and the results need to be compared with satellite data. This allows to control the quality of atmospheric correction and observe possible changes in the satellite sensor calibration over time. Unlike satellite sensors, ground support measurement instruments can be calibrated periodically at the laboratory.

The new type of autonomous spectrometer created within the project will be tested in the most extreme conditions on Earth: in Antarctica, the Namib desert, the Argentinian rainforest, the North Sea and, of course, on the test sites of our environmental observatory at Järvselja. It is necessary to ensure that the complex optics, mechanics and the software that keeps them running work without a glitch.

“Autonomous devices of this type are like small clever robots that need to be able to manage at all times and send the researchers both the measurement data and information about their own condition,” said Viljo Allik, engineer at Tartu Observatory’s Department of Space Technology and supervisor of the ESTCube project. Allik will consult the HYPERNETS project partners on the testing of electronics, software and electromagnetic compatibility.

Riho Vendt, Head of the Department of Space Technology at Tartu Observatory stated that the observatory plays a key role in this project. In the optical radiometry laboratory of the observatory, similar research on different parameters of remote sensing instruments and calibration opportunities has been done ordered by the European Space Agency or as part of European Union cooperation projects. This is why Tartu Observatory has a lot of experience in building instruments as well as dealing with possible measurement errors, their causes, and correction algorithms. “This gives us a chance to get the best possible result with using cheaper components and therefore provide high-quality data at an affordable price,” Vendt said.

The HYPERNETS project is coordinated by the Royal Belgian Institute of Natural Sciences. Besides Estonia, there are project partners from six countries: France, Argentina, Italy, Germany, and the United Kingdom.

 

More information: Joel Kuusk, Senior Research Fellow at Tartu Observatory’s Department of Remote Sensing, joel.kuusk [ät] ut.ee, project website.