Abstract: A system and method for more accurately and robustly determining the heading of a vehicle by taking measurements of angle rates using rate sensors mounted on a movable mechanical assembly. In a quasi-static state of the vehicle, the mechanical assembly is rotated around axes perpendicular to the tangent plane of the Earth, and angle rates are measured by the rate sensors at different rotational angles of the mechanical assembly. The measurements of the angle rates are then computed to determine the initial heading of the vehicle relative to the true north of the Earth in the quasi-static state of the vehicle. After determining the initial heading, navigation state propagation is performed to determine the heading of the vehicle in non-quasi-static state of the vehicle. By taking measurements of the rate sensors at different rotation angles and performing computation, the heading of the vehicle relative to the Earth's true north can be determined using less accurate angle sensors.