Reflection will fall within a narrow wedge on the plot that is centered on its vertical axis. 反射波落在图上以垂直轴为中心的一个狭窄的楔状带内。
In order for a gyrocompass to be accurate it is obviously necessary to hold spurious vertical torques to an extremely low level. 为了使陀螺罗盘做得准确,很明显有必要使垂直轴干扰力矩减小到很低。