If the reference mirror has tilt and piston errors caused by phase-shifting, the phase shifts of the pixels along the same interferogram are not a constant, but they are still kept on the same plane.

• 当相移器存在的相移误差包括位移误差与倾斜误差时，同一幅干涉图诸像素点的相移并不同步，但其相移量在同一平面上。