Abstract:The active radar homing is employed for air-defense missiles regularly. The guidance accuracy is determined by the detection range, angular accuracy and time constant of active radar seeker. But it is hard to quantitatively analyze the influence which causes that the reasonableness of index decomposition of guidance and control system can not be evaluated. In this paper, a rapid assessment method based on physical modeling is proposed. Firstly, a mathematic description is established. The numerical assessment method is adopted to obtain the quantitative analysis criterion of guidance accuracy with proportion navigation. It shows that the proposed method is well under the quantitative influence result of heading error, angular accuracy of seeker, minimum detection range and the available acceleration. These will be a reference for index decomposition of guidance and control system.