the missile knows where it is

导弹时刻知道自己在哪里。
它之所以知道，是因为它知道自己不在哪里。
通过用它不在的地方减去它在的地方，
或者用它在的地方减去它不在的地方（以较大的为准），
它得到了一个差值，即偏差。
制导子系统利用偏差产生修正指令，
驱动导弹从它在的位置移动到它不在的位置，
而当它到达之前不在的位置时，它现在就在那里。
因此，它现在在的位置，
就是它之前不在的位置，
由此可见，它之前在的位置，
现在成了它不在的位置。
如果它现在在的位置不是它之前不在的位置，
系统就产生了一个变差，
这个变差就是导弹目前所在位置与之前不在位置之间的差值。
如果变差被认为是一个重要因素，
它也可以由GEA（制导电子组件）进行修正。
然而，导弹还必须知道它之前在哪里。
导弹制导计算机的运行逻辑如下：
由于变差修改了导弹获取的部分信息，
它不确定自己究竟在哪里。
然而，在合理范围内，它确定自己不在哪里，
并且它知道自己之前在哪里。
现在，它用它之前不在的位置减去它应该在的位置，
或者反之，并通过将此结果与
它不应该在的位置及其之前所在位置的代数和进行求差，
它能够获得偏差及其变差，
而这被称作误差。

The missile knows where it is at all times.
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 where it is (whichever is
Greater), it obtains a difference, or deviation.
The guidance subsystem uses deviations to generate corrective
Commands to drive the missile from a position where it is to a
Position where it isn't,
And arriving at a position where it wasn't, it now is.
Consequently, the position where it is,
Is now the position that it wasn't,
And it follows that the position that
It was, is now the position that it isn't.
In the event that the position that it is in is not the position that
It wasn't, the system has acquired a variation,
The variation being the difference between
Where the missile is, and where it wasn't.
If variation is considered to be a
Significant factor, it too may be corrected by the GEA.
However, the missile must also know where it was.
The missile guidance computer scenario works as follows.
Because a variation has modified some of the information
The missile has obtained, it is not sure just where it is.
However, it is sure where it isn't,
Within reason, and it knows where it was.
It now subtracts where it should be from where it wasn't,
Or vice-versa, and by differentiating this from the algebraic sum of
Where it shouldn't be, and where it was,
It is able to obtain the deviation
And its variation, which is called error.