Abstract: A tracking servo compensator is disclosed for radar systems which steer their antenna beams using a servomechanism that physically moves the antenna. The disclosed tracking servo compensator permits switching between trackers (e.g. from area to point track) and from one tracked target to another without undesirable transients that could cause loss of track. Rate aiding and target range estimates are provided when tracker base motion is known. The compensator works by providing a servo signal that continually monitors the error in estimated track point line-of-sight angular velocity independent of which tracker is employed or the target being tracked. When base motion is known, this signal is used to update the target range estimate so that an accurate rate aiding signal is available. The servo provides smooth controlled-speed transitions between track points during mode switching, and provides an input for manual slewing of the tracker platform during offset track conditions.