infrared guidance

infrared guidance

A method of guidance in which an IR (infrared) seeker cell and a combined optics and flight control system act to home the vehicle onto the heat source. The illustration indicates the operation of an infrared guidance system. If the missile is headed in the proper direction, the infrared sensor will produce an a-c (alternating current) signal with a frequency equal to the rotational speed of the receiving mirror of the IR sensor. The reference signal-generator will produce a signal of the same frequency and send it to the comparator. In the comparator, the received signal and the reference signals will be phase-compared. The phase angle between the reference signal and the received signal will determine what corrective actions must be taken, and the comparator will send the appropriate commands to the servoamplifier. The controls are then actuated by the servoamplifier.