Abstract: An opportunistic calibration method continuously monitors a smartphone orientation and compensates for its variation, as necessary. The method relies on the probabilistic fusion of built-in sensors; in particular, the GPS, accelerometer, gyroscope, and magnetometer. The calibration method may utilize a state-machine approach along with an orientation stability detection algorithm to keep track of the smartphone orientation over time and to coordinate the calibration process in an opportunistic manner. An orientation calibration method may rely mainly on the probabilistic fusion of GPS and magnetometer sensory data.

Abstract: An opportunistic calibration method continuously monitors a smartphone orientation and compensates for its variation, as necessary. The method relies on the probabilistic fusion of built-in sensors; in particular, the GPS, accelerometer, gyroscope, and magnetometer. The calibration method may utilize a state-machine approach along with an orientation stability detection algorithm to keep track of the smartphone orientation over time and to coordinate the calibration process in an opportunistic manner. An orientation calibration method may rely mainly on the probabilistic fusion of GPS and magnetometer sensory data.