Yaw and center-of-rotation of a platform are determined using a single Global Navigation Satellite System (GNSS) device and an inertial measurement unit (IMU). A measurement center of the GNSS device is disposed on the platform away from the center-of-rotation and arranged in a known spatial relationship with the center-of-rotation. The platform is rotated about the center-of-rotation between a first orientation and a second orientation. The IMU is used to determine a change in pitch, roll, and yaw of the platform between the first orientation and the second orientation. The GNSS device is used to determine a change in position of the measurement center of the GNSS device between the first orientation and the second orientation. The yaw of the platform is determined at the second orientation and the position of the center-of-rotation of the platform is determined in a global coordinate frame.
