THE MISSILE KNOWS WHERE IT IS AT ALL TIMES. IT KNOWS THIS BECAUSE IT KNOW WHERE IT ISN'T. BY SUBTRACTING WHERE IT IS FROM WHERE IT ISN'T, OR WHERE IT ISN'T FROM WHERE IT IS, WHICHEVER IS GREATER, IT OBTAINS A DIFFERENCE, OR DEVIATION. THE MISSILE KNOWS WHERE IT IS AT ALL TIMES. IT KNOWS THIS BECAUSE IT KNOW WHERE IT ISN'T. BY SUBTRACTING WHERE IT IS FROM WHERE IT ISN'T, OR WHERE IT ISN'T FROM WHERE IT IS, WHICHEVER IS GREATER, IT OBTAINS A DIFFERENCE, OR DEVIATION.