The performance of an optical system with sensitive line-of-sight (LOS) is influenced by rotational vibration. In view of this, a design methodology is proposed for a passive vibration isolation system in an optical system with sensitive LOS. Rotational vibration is attributed to two sources: transmitted from the mounting base and generated by modal coupling. Therefore, the elimination of the rotational vibration caused by coupling becomes an important part of the design of the isolation system. Additionally, the decoupling conditions of the system can be obtained. When the system is totally decoupled, the vibration on each degree of freedom (DOF) can be analyzed independently. Therefore, the stiffness and damping coefficient on each DOF could be obtained by limiting the vibration transmissibility, in accordance to actual requirements. The design of a vibration isolation system must be restricted by the size and shape of the payload and the installation space, and the layout constrains are thus also discussed.

具有敏感视线（LOS）的光学系统的性能会受到旋转振动的影响。鉴于此，提出了一种用于具有敏感LOS的光学系统中的无源隔振系统的设计方法。旋转振动可归因于两个来源：从安装基座传递并由模态耦合产生。因此，消除由耦合引起的旋转振动成为隔离系统设计的重要部分。另外，可以获得系统的去耦条件。当系统完全解耦时，可以独立分析每个自由度（DOF）上的振动。因此，可以根据实际需要通过限制振动的传递性来获得每个自由度的刚度和阻尼系数。