backsight的翻译，读音
英/'bæksait/
释义：
n. 后视, 表尺缺口
n. The reading of the leveling staff in its unchanged
position when the leveling instrument has been taken to a new position;
a sight directed backwards to a station previously occupied. Cf.
Foresight, n., 3.
n. The reading of the leveling staff in its unchanged
position when the leveling instrument has been taken to a new position;
a sight directed backwards to a station previously occupied. Cf.
Foresight, n., 3.