This paper describes an algorithm that tracks and localizes a helicopter using a ground-based trinocular camera array. The three cameras are placed independently in an arbitrary arrangement that allows each camera to view the helicopter’s flight volume. The helicopter then flies an unplanned path that allows the cameras to self-survey utilizing an algorithm based on structure from motion and bundle adjustment. This yields the camera’s extrinsic parameters allowing for real-time positioning of the helicopter’s position in a camera array based coordinate frame. In fielded experiments, there is less than a 2m RMS tracking error and the update rate of 20Hz is comparable to DGPS update rates. This system has successfully been integrated with an IMU to provide a positioning system for autonomous hovering.