Space and scientific instrumentation
High Tech Industry


In cooperation with

Airbus Defence & Space Netherlands, SRON, KNMI

The satellite instrument TROPOMI is the most sophisticated and accurate instrument ever to carry out measurements from space for the purposes of climate and air pollution research. TROPOMI has been conceived and designed by experts in optics and mechanics at TNO and Dutch Space and has been built largely by the Dutch manufacturing industry. On 13 October 2017 this instrument, which is incorporated in the European satellite Sentinel-5Precursor, was launched by the European Space Agency (ESA) and has since been orbiting the Earth at an altitude of 824 kilometres collecting data. On 1 December 2017 the first measurements were received from TROPOMI. These measurements are more accurate than anything that has preceded them. The instrument sees air quality with more clarity than ever before, something that would not have been possible without TNO's knowledge.

Freeform optics

TROPOMI is a revolutionary technology that uses freeform optics to produce razor-sharp images and the most accurate information to date. TROPOMI has four detectors, together capable of detecting wavelengths in the infrared, visible and ultraviolet light spectrums. By comparing sunlight it has measured in space with light reflected back from Earth it is possible to calculate how certain concentrations of gases, such as ozone, nitrogen oxide and methane, develop in the atmosphere. The opto-mechanical heart of the instrument was developed by TNO: the Ultraviolet Visible Near-infrared optical bench module (UVN-OBM). This consists of the shared telescope and calibration unit and three of the four spectrometers that TROPOMI carries. This equipment is used to produce an image of the Earth every second, with a resolution of seven by seven kilometres.

Accurate climate research

Thanks to the precision of this instrument, air pollution is being mapped right down to city level, whereas its predecessor was working at the level of the Dutch provinces.  In addition, it can distinguish between various sources of pollution, which means that measures can be taken. This information is important because it affords an insight into how clean the air is at the local level, which in turn enables government agencies to see whether environmental regulations are being followed.

TNO's expertise

‘We had to push boundaries to achieve very high resolutions and realise a broad dynamic range in a light, small and compact device,’ says Adriaan van 't Hof, TROPOMI project manager. ‘Our experts developed new technologies to do this, such as freeform optics so that mirrors and lenses could be produced in unprecedented forms. Another new technique was that of immersed grating, which involves applying minuscule grooves to glass in order that light can be split into various wavelengths. None of this had previously been shown to the world.'

Cooperation at global level

TROPOMI was designed for the Netherlands Space Office and ESA and built by Dutch Space in close cooperation with TNO as technological partner, and SRON and KNMI as scientific institutes. Dozens of specialist SMEs in the Netherlands and further afield were involved as suppliers of components and coatings.

Would you like more information about TROPOMI and freeform optics? If so, feel free to contact us.

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Quantum internet enabled by space


Building on our combined know-how in quantum, free space optics and classical networks, TNO is working hard to enable quantum internet from space. In this webinar, Charlotte Postma and Gustavo Castro do Amaral will get you up to speed on the achievements so far, and the steps ahead.


TNO joins European collaboration to develop global quantum internet enabled from space

1 September 2023

TNO and the Institute of Communication and Computer Systems (ICCS) and a consortium of other European partners, join forces in the LaiQa-project (Leap in Advancing of critical Quantum key distribution-space components).

TNO & partners bring deep-space communication a step closer

16 June 2023

Could there ever be a space station on the moon? Or a shuttle to orbit around Mars? Perhaps. But only if there’s an effective communication system in place. Recently, TNO and its partners completed a project that will enable effective communication from a Lunar Gateway, an orbiter around Mars, or deep-space exploration missions. With the successful development of a breadboard optical communication terminal, TNO and its partners have brought the entire industry a significant step closer to its deep-space ambitions.

Satellite instrument OMI orbits Earth for 100,000th time

4 May 2023

This week, the Ozone Monitoring Instrument (OMI) reaches a milestone: 100,000 orbits of Earth. This is extra special because the monitoring instrument was originally designed for a six-year mission after its launch in 2004. OMI has since been monitoring atmospheric emissions and the ozone hole for more than 18 years, which has provided a lot of useful data. This enabled TNO, for instance, to measure the effects of stricter air quality policies in European countries.

Jan Nijenhuis appointed Knight in the Order of the Lion of the Netherlands

26 April 2023

Jan Nijenhuis Knight has been appointed Knight in the Order of the Lion of the Netherlands. This royal appointment is an acknowledgement of his ground-breaking research in the field of opto-mechatronics. Today, Jan received the decorations that go with this award from Marja van Bijsterveldt, mayor of the city of Delft.