iSPEX: First Results of Aerosols Measured by Smartphones in The Netherlands

An increasing number of people carry a smartphone with internet connection, a camera and considerable comput- ing power in their pocket. iSPEX, a spectropolarimetric add-on with complementary App makes use of this oppor- tunity, and instantly turns a smartphone into a scientific instrument to measure dust and other aerosols in our at- mosphere. A measurement involves scanning the blue sky, which yields the angular behavior of the degree of linear polarisation as a function of wavelength, which may be interpreted in terms of size, shape and chemical composition of the aerosols in the sky. The measurements are automatically tagged with location and pointing infor- mation, and submitted to a central database where they will be interpreted. Together with observations from other users at random locations, the data are compiled into a map. Through crowd sourcing, the general public will thus be able to contribute to a better assessment of the presence of different types of aerosols in the atmosphere.