Living environment
Citizen science

Introducing the iSPEX® Smartphone Spectrometer and Polarimeter – a cost-effective and versatile solution for monitoring water and air quality, as well as engaging in a wide array of STEM activities and experiments. Effortlessly compatible with numerous smartphones, the iSPEX® device empowers users to collect and scrutinize data with precision and ease. Ideal for citizen science initiatives, in-depth environmental studies, and even recreational exploration, iSPEX® simplifies the data collection process without compromising on quality. Moreover, our state-of-the-art app and platform enable efficient data analysis and promote seamless sharing of results with relevant parties, enhancing the overall user experience.


You might find that the light from the sun is much different from the light from a streetlamp, or that the light from a candle is quite different from the light from a firefly. As you experiment, you'll start to understand the different properties of light and how it interacts with the world around us. Download the app, grab a spectral image and start sharing! 

Water quality:

Like air, water can also scatter and reflect light, which can cause the light to become polarized. By measuring the polarization of light that passes through water, spectropolarimetry can be used to detect the presence of certain particles or substances in the water, such as algae, bacteria, or pollution. This information can be used to monitor the quality of water in rivers, lakes, or oceans, and to identify sources of pollution. Spectropolarimetry is just one of many tools that can be used to study water quality, and it can be a valuable tool for scientists and policymakers who are working to protect the world's water resources.

Air quality:

Spectropolarimetry is a scientific technique that involves measuring the polarization of light, and it can be used to study air quality. A campaign in 2014-2015 obtained great results with the iSPEX 1 unit. 

Citizen Science with iSPEX

The app and platform provide essential user feedback and notifications.

Push notifications are messages that are sent to a user's smartphone or other device to alert them to new information or events. In the context of citizen science, push notifications could be used to inform people about new research projects or opportunities to participate in scientific research. For example, our  iSPEX citizen science app could send push notifications to users to let them know about new data collection campaigns, or to remind them to submit their data. Push notifications could also be used to provide updates on the progress of a research project, or to share interesting findings with users. By using push notifications, citizen science apps can help to engage users and keep them informed about the latest developments in scientific research.

Past campaigns: water and atmosphere

Measuring water reflectance with iSPEX during the MONOCLE field campaign.

Relevant papers and articles:

Standardized spectral and radiometric calibration of consumer cameras. Burggraaff O. et al. Optics Express, Vol 27, Issue 14, 2019.
A universal smartphone add-on for portable spectroscopy and polarimetry: iSPEX 2. Burggraaff O. et al. Proc. SPIE 11389, Micro- and Nanotechnology Sensors, Systems, and Applications XII, 2020.

Ispex 1
Ispex 2
Ispex 3

The team

Thanks to the EU projects, we were able to develop iSPEX and conduct valuable research with it. The support from the teams at Leiden University (Astronomy) and Bright Led Solutions (hardware) has been instrumental in allowing us to continue this development.

Norbert Schmidt

Owner / PI

Frans Snik PhD

Researcher Leiden University

Joep van der Heiden

Full stack developer / co-investigator

Publications (1)

A universal smartphone add-on for portable spectroscopy and polarimetry: iSPEX 2

Olivier Burggraaff, Armand B. Perduijn, Robert F. van Hek, Norbert Schmidt, Christoph U. Keller, Frans Snik