Systems and methods for tracking a heading of an excavator are provided. An initial heading of the excavator platform is obtained and a current azimuthal orientation of the excavator platform is associated with the initial heading. Coordinates of a measurement center of the GNSS device are obtained. Coordinates of a center of rotation of the excavator platform are determined using the initial heading of the excavator platform, the coordinates of the measurement center, and a known spatial relationship between the measurement center of the GNSS device and the center of rotation of the excavator platform. Rotation of the excavator platform is tracked from the initial heading to a first heading using rotation measurements from a swing sensor.