Living environment
Citizen science

Introducing the iSPEX® smartphone spectrometer and polarimeter - the ultimate tool for measuring water and air quality, and so much more! With iSPEX®, you can easily attach the unit to almost any smartphone, giving you the power to collect and analyze data like never before. Whether you're conducting a citizen science campaign or simply want to learn more about the world around you, iSPEX® makes it easy to get started. Plus, our powerful app and platform make it a breeze to analyze data and share your results with others. 


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

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