The periscope and the change of periscope depth caused by changed the interval between of two lens inverted image system are simply described.

• 对潜望镜及改变双透镜转像系统间的间隔来实现潜望高度的改变进行了简要说明,并对转像系统间隔变化对整个系统性能可能产生的影响,进行了分析及计算。