So much for the description of the reticle. Now let’s talk about this term ‘disturbed.’ What is this word referring to? Let’s go back to where we were talking about gyroscopes. We said that a gyroscope would react if a force was applied to it. This reaction (precession) is the gyro being ‘disturbed’ from its static position. In gunsight terms, the word ‘disturbed’ refers to reticle precession behavior of gyro-based sights. So…a disturbed reticle sight is any sight using gyro precession as the means of determining reticle position.
Next question. What forces cause the gyro to precess? Two forces…pitch and yaw. Pitch means G…pushing or pulling on the pole. Yaw means rudder…pushing the rudder pedals one way or the other. In a one G condition, the reticle will be close to the fixed gun line. Pulling back on the stick causes the reticle to move towards the bottom of the HUD or combining glass. If the pilot then relaxes G, the pipper will move back up towards the gun line position. If the pilot pushes negative G, the reticle will move above the gun line position.