A far-field antenna characterization system for characterizing a far-field antenna pattern of a target antenna. An unmanned aircraft system (“UAS”) with a flight control system receives preprogrammed flight instructions for maneuvering the UAS within the far-field antenna pattern of the target antenna. A sensing antenna mounted to the UAS senses the far-field antenna pattern of the target antenna. A power measurement sensor provides a power level signal indicative thereof. A position measurement sensor provides a position signal for the UAS. The data logger associates the power level signal with the position signal at multiple measurement points to create a power density pattern for the far-field antenna pattern.