Together with the European Space Agency in the fight against global warming

The European project ESA-ONE promises to revolutionise gas monitoring, namely carbon dioxide, in the atmosphere. Developed with the European Space Agency, this project, which had the participation of INESC TEC’s Centre for Applied Photonics (CAP), represents a step forward as far as greenhouse effect and consequent global warming are concerned. With the use of sensors – a technology with which INESC TEC has been demonstrating extremely positive results – in ESA’s satellites, it will now be possible to explore the Earth from space more effectively.

The participation of INESC TEC

Ever since Portugal became member of ESA in November of 2000, we have been witnessing the continuous effort to maximise the Portuguese contribution to this European agency. The ESA-ONE project was submitted after a call for applications was launched in the context of the “ESA - Portugal Task Force”, one of the Portuguese initiatives to strengthen the country’s visibility in the Agency’s activity. The contacts that José Luís Santos, coordinator of UOSE, established with Nikos Karafolas and João Pedro do Carmo from the European Space Agency thus resulted in a pioneer and innovative project for INESC TEC and for the world.

CAP’s team participating in the development of the ESA-ONE project included researchers José Luís Santos, Francisco Araújo (project coordinator), Luís Ferreira, Dionísio Pereira, João Ferreira, Susana Silva, José Carlos Azevedo and Ireneu Dias. The project lasted 30 months with a budget of 175 thousand Euros.

Objectives and main challenges for the project

The aim with this project that started in 2006 is to develop an integrated filter based on high resolution micro-optics for LIDAR applications (Laser Detection and Ranging). The intention is to monitor carbon dioxide levels in the atmosphere. According to Francisco Araújo, other than this filter, the project’s main challenges have to do with “the development and implementation of heat-reflecting tunable packaging for FBG filters (fibre Bragg gratings), as well as the development and implementation of an ultra-narrow spectral filter based on an FBG chirp with phase jump, and a microfilter for the rejection of background radiation.”

Other than the technical requirements, such a project also entails a lot of responsibility given how demanding it is to work with a client such as ESA. Questioned about the current state of the project, Francisco Araújo reveals that the prototype is currently being “assessed for performance”, undergoing “temperature, vibration and shock tests.”

One step forward in the environmental issue

One of the main benefits of the project has to do with the use of filters in order to determine the concentration of gas (specifically CO2) in the atmosphere from satellites at an altitude of 400 km (250 miles). The filter will then detect back-reflected radiation of laser impulses.

In a time when climate issues are at the centre of global discussions, “the project is critically important to the study of the greenhouse effect and global warming because it enables this measurement [of gases] throughout altitude profiles”, Francisco Araújo adds.

The future of a successful cooperation

Compared with alternative systems, which are based on conventional optics, this new system offers a higher level of integration. However, conventional systems are already qualified for “orbital missions – i.e. Technology Readiness Level (TRL) 8 – while INESC TEC’s project is still at a laboratory prototype TRL 2 stage”, the researcher added. Thus, the aim is for INESC TEC to continue developing this technology in order to go up the TRL scale and broaden the system’s use. The project will be concluded with the evaluation meeting that will take place in the city of Porto and with the meeting for the presentation of the results at ESTEC-ESA (European Space Research and Technology Centre) that will take place in Noordvik, Netherlands.

After that, ESA will be able to start implementing LIDAR systems in future orbital missions. According to the project’s coordinator, this will “lead to the integration and reduction of all auxiliary systems, with a special emphasis on optical filtering systems”. The researcher mentions that the “project’s results will also be assessed for possible future incorporation in scientific missions to other planets with LIDAR systems.”