Gravimetric Detection of Earth's Rotation Using Crowdsourced Smartphone Observations.

When proper measurement and calibration protocols are applied, smartphone sensors can generate relatively good-quality data that compare well with professional-grade, calibrated systems, but at far-lower cost. This paper investigates one of these applications involving the accelerometer sensor. Earth's rotation causes a slight change in local surface gravity between the Polar and Equatorial regions with a magnitude of approximately 0.05 m/s(2). Typical smartphone platforms can measure accelerations to an accuracy of +/- 0.01 m/s(2). Provided that measurements are made with some care, a series of crowdsourcing campaigns demonstrate that the rotation of Earth is indeed detectable through differential gravimetry with modest statistical significance using commonly available smartphone platforms.