The missile maintains constant awareness of its location. This is achieved through its intrinsic understanding of where it is not. By calculating the difference between its current position and where it isn't, either by subtracting its current location from where it isn't or vice versa, the missile computes a deviation. This deviation is then utilized by the guidance subsystem, which is programmed to issue corrective commands. These commands are designed to reposition the missile from its current location to a desired one. As the missile reaches a location where it previously wasn't, it updates its current position. This means that the missile's present location is now where it used to be absent. Consequently, the position that the missile occupied before is now a location where it is not.

In situations where the missile finds itself in a position other than where it intended to be, the system identifies a discrepancy. This discrepancy is quantified as the difference between the missile's current and intended positions. When this variation is significant, it can be adjusted by the Guidance Electronic Assembly (GEA). However, for the GEA to make effective corrections, the missile must have knowledge of its previous position. This historical data assists in accurate recalibration, ensuring the missile's course remains true to its intended trajectory.

The missile guidance computer operates on a complex principle. When a variation alters the information regarding the missile's position, uncertainty arises about its exact location. However, the system is fairly certain about where it is not and remembers where it was. It computes its current position by subtracting where it should be from where it was not, or the other way around. This calculation is refined by contrasting it with a composite of where it should not be and where it was. Through this process, the missile identifies both the deviation from its intended path and the extent of this deviation, known as the error. This error calculation is critical for realigning the missile's trajectory toward its intended target, ensuring high precision in navigation and impact.