Objectives  Since the geometric parameters of the ship air-intake grilles are numerous, the calculation cost of radar wave stealth performance optimizing for all parameters is too high, and the geometric parameter sequences with high Radar Cross Section(RCS) sensitivity need to be mastered.

  Methods  In this paper, taking one typical air-intake grille of ship as the object, the parameterized modeling, the electromagnetic scattering calculation parameters and the electromagnetic scattering calculation method of the grille had been carried out. The sensitivity of each geometric parameter to shielding efficiency was calculated by using the central finite difference method.

  Results  The variation law of radar scattering characteristics under different geometric parameters, and the geometric parameter sequence for stealth optimization of the air-intake grilles were obtained.

  Conclusions  The stealth analysis and sensitivity calculation method constructed in this paper is reasonable and feasible, and can be widely used in the stealth optimization design of naval air-intake grille.