A method and apparatus for calibrating a set of transducers. In one illustrative embodiment, an apparatus comprises a target device, an imaging device, and a calibrator. The imaging device generates a plurality of images of a target formed by the target device as the target device is rotated relative to the imaging device about a pivot axis formed at an interface between a first structure and a second structure in response to the first structure being rotated about the pivot axis relative to the second structure. The calibrator identifies a plurality of angles of the target about the pivot axis using the plurality of images. The calibrator further identifies calibration information using the plurality of angles.