Dutch researchers were able to successfully map levels of atmospheric particulates by pulling data from over 8,000 smartphone users.
A team from the University of Leiden in the Netherlands developed a smart-phone adaptor called an iSPEX. This inexpensive, mass-producible add-on is attached to the front of the phone’s camera that enables it to function as a spectropolarimetric instrument.
Over the course of three different cloud-free days, users of those phones were able to collect data about atmospheric dust levels at a level of accuracy that at times exceed measurements from ground-based networks and satellite instruments.
The technology works by having participants attached the small iSPEX device to their phone’s camera.
On the selected days of the experiment, those users were instructed to scan the sky with the phone’s camera which then captured pictures and collected information about the the spectrum and the linear polarization of the sunlight that is scattered by suspended dust particles.
The data collected by citizen scientists was averaged and a map showing Aerosol Optical Thickness (AOT) was created for each of the three days.
The spatial resolution of the data collected via the ISPEX devices was two kilometers and offered a finer grained resolution than comparable satellite data.
The results of the research was recently published in the journal Geophysical Research Letters:
Snik, F., Rietjens, J. H., Apituley, A., Volten, H., Mijling, B., Di Noia, A., … & 3187 iSPEX citizen scientists. (2014). Mapping atmospheric aerosols with a citizen science network of smartphone spectropolarimeters. Geophysical Research Letters, 41(20), 7351-7358.
The future goal is to expand the project globally. Frans Snik, the lead researcher explained, “Our final goal is to establish a global network of citizen scientists who all contribute measurements to study the sources and societal effects of polluting atmospheric particles.”
More information about the project can be found on the iSPEX page.