Measure water and air quality with iSPEX
Transform your smartphone into a research-grade spectropolarimeter. Measure water quality, air pollution, and conduct citizen science with professional accuracy.
Current Status
We are currently finalizing Rrs validation with Plymouth Marine Lab. Meanwhile, we are updating the app. If you're interested in iSPEX2, sign up for our newsletter to stay informed.
✓ Finalizing validation with Plymouth Marine Lab ✓ App updates in progress
Compatible with recent 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. iSPEX is currently being validated with leading research groups.
Breakthrough: Remote Reflectance (Rrs) Validation
iSPEX2 achieves the holy grail of above-water measurements: accurate remote reflectance (Rrs) comparable to equipment costing tens of thousands of euros. This breakthrough was validated by Dr. Tom Jordan and Prof. Stefan Simis in 2024 during the AMT31 campaign.
Scientific Validation: iSPEX2 Rrs measurements (colored lines) closely match professional HyperSAS equipment (grey lines) across multiple wavelengths. Validated by Dr. Tom Jordan and Prof. Stefan Simis, 2024.
This validation demonstrates that iSPEX2 can deliver professional-grade water quality measurements at a fraction of the cost, making advanced oceanographic research accessible to institutions worldwide.
What is Remote Reflectance (Rrs)?
Remote reflectance (Rrs) is the "gold standard" measurement in water quality science. It tells us exactly how much light bounces off water at different colors (wavelengths), revealing what's in the water - algae, sediment, pollution.
Until now, measuring Rrs required expensive equipment costing tens of thousands of euros, limiting it to well-funded research institutions. iSPEX2 achieves the same accuracy for under €200, democratizing professional water quality monitoring.
Why Rrs matters: It's the same measurement satellites use, so iSPEX data can validate and enhance satellite monitoring of lakes, rivers, and coasts worldwide.
SPEX Technology
iSPEX uses SPEX spectropolarimetry technology, which is also deployed on NASA's PACE satellite mission. This shared methodology makes iSPEX well-suited as a validation instrument for satellite observations.
Spectropolarimetry using the SPEX method is sophisticated technology typically found in research-grade instruments. iSPEX makes this accessible through smartphone integration.
iSPEX® name, logo, and design are registered through the Benelux Patent Office (BOIP). EU registered trademarks.
Water quality applications
Particles such as algae, minerals and detritus, as well as dissolved substances, colour the water by absorbing and scattering sunlight. By measuring the reflected light, iSPEX can be used to determine colour properties that relate to biogeochemical water quality. Combined with other information from water samples this information can be used to monitor water quality of rivers, lakes, or oceans, and to identify sources of pollution. Spectro(polari)metry is uniquely suitable to combine with satellite observations of water quality and should be considered in cases where additional local-scale water colour information can help monitor and protect the world's water resources.
Introduction Video
Instructional videos
iSPEX Assembly
Positioning the iSPEX unit
Example water measurement protocol (Hydrocolor alike)
Current Research Users
iSPEX2 is currently being used by leading research institutions worldwide:
- LandSeaLot Consortium - Ocean color validation studies
- Plankton Planet, University of Maine - Marine ecosystem monitoring
- Vrije Universiteit Brussel - Environmental sensing research
- Leiden University - Atmospheric and water quality studies
- Sorbonne University Mission Bougainville - Oceanographic research
Citizen Science with iSPEX
iSPEX (1) was used with over 10,000 citizens to generate a high precision map of air pollution. We have more than ten years experience in citizen science projects. iSPEX 2 will be suitable for large scale citizen science campaigns. Think of satellite validation or environmental monitoring.
Frequently Asked Questions
What configurations are offered?
For research applications, we provide comprehensive kits that include:
- A calibrated research-grade smartphone
- Professional grey cards for calibration
- Durable carrying case
- Calibration lamp
- Detailed research methodology manual
- Optional: transmission case (cuvette) for specialized experimental projects
What apps complement the product?
Our research-oriented applications include the 'iSPEX Water' apps for both Android and iOS, specifically designed for advanced calibration and water quality analysis. These apps feature professional-grade tools for spectral analysis, data collection, and research documentation.
Which smartphones can run iSPEX?
Most recent Android and iPhone models are compatible. iOS 13 and up are supported and the Android phones that support Camera2 (Raw imaging).
Who's behind iSPEX?
The current team consists of Norbert Schmidt and Joep van der Heiden (of DDQ Pocket Science), hardware design and early production by Armand Perduijn. We work closely together with Stefan Simis and Tom Jordan from Plymouth Marine Lab, Frans Snik and Olivier Burggraaff from Leiden University. Credit goes to Frans Snik and Jeroen Rietjens from Leiden University and SRON. They are the founding fathers.
Can I order single iSPEX units?
We no longer offer single unit orders. iSPEX units are available only as part of comprehensive research kits or through bulk orders with a minimum order quantity (MOQ) of 150 units.
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.
iSPEX2 smartphone spectropolarimeter and mounting backplate