Join iSPEX-EU and Measure Air Pollution with your Smartphone

The iSPEX and LIGHT2015 projects organize the first Europe-wide citizen-science photonics experiment to measure air pollution using smartphones from 1 September to 15 October 2015. With the iSPEX add-on and app, you can transform your smartphone into a scientific tool to measure tiny particles in the atmosphere that contribute to air pollution and its impacts in an as-yet poorly understood way. iSPEX-EU forms a network of thousands of people all over Europe that perform iSPEX measurements and provide information at locations and times that are not covered by current air pollution monitoring efforts – and we need your help! By joining iSPEX-EU you can be part of a major project to help understand our atmosphere and make an important scientific contribution!


iSPEX is a passive spectropolarimetric add-on for smartphones that uses the phone’s camera, sensors, computing and communications capabilities. The application of iSPEX is two-fold: 1) It enables crowd-sourced measurements of tiny atmospheric particles, also known as aerosols, at locations and times that are not covered by current air pollution monitoring efforts. 2) It makes atmospheric science accessible to everyone, by active participation in scientific measurements.

The iSPEX app instructs participants to scan the cloud-free sky while the phone’s built-in camera takes pictures through the add-on. Each picture taken through the iSPEX add-on contains information on both the spectrum and the linear polarization of the incident, scattered sunlight. The measured degree of linear polarisation as a function of wavelength and, obtained by pointing the phone at different directions in the sky, as a function of scattering angle, yields unique information on fundamental aerosol properties, including the amount of aerosol, and also the particle size distribution and the chemical composition. This type of measurement is crucial in assessing the impacts of atmospheric aerosols on health, environment and air traffic.


With the advent of smartphones and the development of iSPEX citizens can now contribute to these crucial measurements and together form a flexible network that can deliver measurements everywhere, even where no specialised equipment is available, and at any daylight hour. The active involvement of citizens in an important and real scientific experiment, pioneering a new form of citizen science where participants carry out complex, simultaneous mass-measurements, is the most important aspect of this project.

Following an initial citizen science campaign in the Netherlands in 2013, where thousands of participants took measurements of Dutch air pollution, the iSPEX project is now crossing borders with a first Europe-wide citizen campaign: iSPEX-EU. This campaign will run from 1 September to 15 October 2015, in major cities in Europe: Athens, Barcelona, Belgrade, Berlin, Copenhagen, London, Manchester, Milan, and Rome.

It is expected that the collected data will lead to scientific publications that will be made accessible to the general public. A live online map will show qualitative results of the experiment.

For more information on how to join the campaign visit Follow also the twitter @ispex_eu account for the latest updates.

About Leiden Observatory

Leiden Observatory is part of Leiden University, one of Europe’s foremost research universities and lead institute of the iSPEX consortium. Its astronomical instrumentation researchers have developed the iSPEX smartphone add-on. Leiden Observatory is the world’s oldest university observatory and is one of the world’s leading astronomical institutes with over 25 faculty and over 70 PdD students.

Leiden Observatory plays an active role in astronomical outreach activities at local, national and international levels. It hosts the Universe Awareness (UNAWE) programme, which educates and inspires young children. With iSPEX add-on and app for the smartphone, Leiden Observatory introduces a new measurement technique for tiny atmospheric particles that make significant part of air pollution, but more important, also a modern measurement philosophy: citizen science. As such, iSPEX fosters scientific literacy and awareness of the environment in its participants, in young and old, in their families and friends, in bystanders, and in the general public through media exposure.


About LIGHT2015

LIGHT2015 is a European project funded through the European Union’s Horizon 2020 research and innovation programme of the European Commission. It aims to promote the importance of photonics to young people, entrepreneurs and the general public in all Member States of the EU during the International Year of Light and Light-based Technologies 2015 (IYL 2015).

LIGHT2015 activities will include LIGHTtalks, a series of inspirational events, which will take place throughout the European Union in different cities at different times for the whole duration of the project in order to bring photonics closer to students and entrepreneurs. A specific series of events targeted to local industry and entrepreneurs, will take place during the period 25-28 September 2015 to take advantage of the international “100 Hours / Weekend of Light” of the global IYL 2015 programme.

Another highlight of LIGHT2015 will be a community experiment on smartphone photonics where thousands of participants from throughout the EU will carry out optical measurements of the sky to yield information related to air pollution. To aid teachers and to inspire student, Photonics kits will be distributed to schools around Europe to support the scientific education at secondary schools.

LIGHT2015 Partners include the European Physical Society (EPS), the European Optical Society (EU), the Institute of Photonics Sciences (ICFO), Politecnico di Milano (POLIMI) the National University of Ireland Galway (NUI), Universiteit Leiden and EYESTvzw.


Elise Hendriks
iSPEX-EU Coordinator

Jorge Rivero González
LIGHT2015 Project Officer

David Lee
LIGHT2015 Coordinator