Systems, methods, and apparatus are provided in a vehicle having a Hitch Articulation Angle (HAA) calculation system for estimating an HAA between the vehicle and a towed trailer. The method includes: receiving a plurality of ultrasonic sensor (USS) range measurements for a first USS on the vehicle while the vehicle is towing the trailer in a forward direction; receiving a plurality of HAA values calculated using geometric equations or a kinematic model that correspond to the plurality of USS range measurements; receiving a USS range measurement for the first USS while the vehicle is operating in a reverse direction or experiencing a high HAA but not from a second USS; estimating an HAA value from the USS range measurement by applying the USS curve characteristics for the first USS; and providing the estimated HAA value to a vehicle motion control system for use in controlling vehicle and trailer motion.