Crowdsourcing Water Quality Data Using the iPhone Camera

The ubiquity and advanced computing power of smartphones make them a potential tool for environmental monitoring on a global scale. In an attempt to tap this resource, a water quality application (HydroColor) was developed. Hydro- Color uses the iPhone’s digital color camera as a primitive three-band radiometer. Using three images taken by the user, HydroColor calculates the remote sensing reflectance in the red, green, and blue color channels of the camera. The absolute or relative reflectance between channels can be used to obtain estimates of chlorophyll, turbidity, suspended particle material, and the backscattering coefficient. In the future, HydroColor will be linked to an online database where users can upload their measurements, thus crowdsourcing water quality data