Abstract: An apparatus includes a controller coupled to at least two antennas and one or more sensors. An initial azimuth value for the apparatus is determined based on output of the one or more sensors. Respective phase differences between satellite signals received from respective satellites at the at least two antennas are detected, and respective phase difference values for the respective satellites are calculated based on the initial azimuth value, a distance between the at least two antennas in the apparatus, and positions of the respective satellites. An actual azimuth angle of the apparatus is identified based on the initial azimuth value from the output of the one or more sensors and variations between the respective detected phase differences and the respective calculated phase difference values for the respective satellites.