frame of reference
noun
1- a set of criteria or stated values in relation to which measurements or judgements can be made（衡量、判断事物的）参照标准; 参考依据; 标准：
the observer interprets what he sees in terms of his own cultural frame of reference.
观察者用他自己的文化标准解释他所看到的事物。
1.1
- （亦作reference frame）a system of geometrical axes in relation to which measurements of size, position, or motion can be made参考标架, 参考坐标系。