  The characteristics of the inner layer of the atmosphere, the troposphere,
are determinant for the earth's life. In this experience we explore the first
hundreds of meters using a smartphone mounted on a quadcopter. Both the
altitude and the pressure are obtained using the smartphone's sensors. We
complement these measures with data collected from the flight information
system of an aircraft. The experimental results are compared with the
International Standard Atmosphere and other simple approximations: isothermal
and constant density atmospheres.
