测量OTF时所产生的误差,可分为系统误差和随机误差。前者误差是有一定规律的,例如探测器的非线性或扫描狭缝的有限宽度。后者误差是随机性的。例如探测器的噪声引起的,或者在测量中由于系统受振动或干扰引起的。如果我们知道误差产生的原因,则可采取措施,对其进行修正或避免,但对误差进行完全修正或避免实际上是难以实现的。所以为改善测量OTF的精度,重点研究统计误差是很重要的。 The errors produced when measuring OTF can be divided into system error and random error. The former error is a certain law, such as non-linear detector or scan the limited width of the slit. The latter error is random. For example due to detector noise or due to vibrations or disturbances in the measurement. If we know the cause of the error, we can take steps to correct or avoid it, but it is virtually impossible to completely correct the error or avoid it. Therefore, in order to improve the accuracy of measuring OTF, it is very important to focus on statistical errors.