Abstract: A three-axis antenna positioner has an X-Y over azimuth configuration, and includes an azimuth drive assembly, an X-axis drive assembly, and a Y-axis drive assembly. Each drive assembly is independently operable. The azimuth drive assembly imparts 540° azimuthal rotational motion to an antenna about an azimuth axis. The X-axis drive assembly rotates the antenna about a horizontal X-axis at elevation angles between ?90° and +90°. The Y-axis drive assembly rotates the antenna about a Y-axis at elevation complement angles between ?2° and +105°. The azimuth axis, the X-axis, and the Y-axis all intersect at a common intersection point, and are mutually orthogonal. A controller operates each drive assembly so as to minimize antenna tracking velocity and acceleration. Each drive assembly may include dual drives, and may be operated in a bias drive mode to substantially eliminate backlash.

Abstract: A controller is configured to operate an antenna positioner, which positions an antenna to track a moving object during a pass, in dual operational modes. The controller determines a maximum expected elevation angle during the pass. The controller de-activates the azimuth drive assembly and activates the x-axis drive assembly and the y-axis drive assembly, if the maximum expected elevation angle is greater than or equal to a predetermined angle. The controller de-activates the x-axis drive assembly, and activates the azimuth drive assembly and the y-axis drive assembly, if the maximum expected elevation angle is less than the predetermined angle.