Abstract: An angle encoder for determining the pitch (or yaw) angle of a gyroscopic mass with respect to the pitch (or yaw) axis of a missile in flight is shown to be the combination of: (a) an optical encoder pattern disposed on the periphery of the gyroscopic mass, such pattern preferably being divided into a substantially equal reflective portion and a nonreflective portion; (b) an optical sensor arrangement having a limited field of view, such arrangement being mounted on the body of the missile to provide a first signal whose level is indicative of the reflective or nonreflective portion in the limited field of view; and (c) circuitry for converting the first signal into a signal indicative of the pitch (or yaw) angle of the missile.