The missile knows where it is at all times. The Missile It knows this because it knows where it isn't. By subtracting where it is from where it isn't or where it isn't from is (whichever greater)it obtains a difference deviation.The guidance subsystem uses deviations to generate corrective commands drive the missile position isto isn'tand arriving at wasn't now is.Consequently is that wasn'tand follows wasis isn't"