Want to help scientists improve data on air-quality? If you’re an Android user, now all you have to do is take a picture of the sky on a clear day, thanks to a new mobile app, provisionally titled “Visibility,” aimed at helping researchers at the University of Southern California (USC) to monitor air-quality.
The basic principle of the Visibility app is simple,according to a paper documenting the work by USC computer science professor Gaurav Sukhatme. You, the Android user, download the app, then take a picture of the sky while the sun is shining. This picture can then be compared to established models of sky luminance to estimate visibility, a factor which is directly related to the concentration of harmful “haze aerosols,” (tiny particles from dust, engine exhaust, mining or other sources in the air, which turn the blue of a sunlit, clear sky to gray.)
If providing important data to researchers is this simple, you might ask, why haven’t we been doing so with our digital cameras? Therein lies the caveat: in order for these pictures to provide scientists with the right data, they have to be aimed in precisely the right direction–a feat accomplished by use of the smartphone’s sensors, (which include cameras, GPS systems, compasses and accelerometers) that can tell how the user is holding the phone, and which the Visibility app can use to guide the user to point the camera in exactly the right direction. The researchers, from the USC Viterbi School of Engineering, are hoping that a fleet of users will download the software, not only to provide data on air quality, but to help to improve the app, which is still in its infancy. A version for the iPhone is in the works.