The present work investigates the aerothermal effects on the electro-optical performance of a conceptual infrared seeker missile at Mach 4 at small angles of attack. Two window dome configurations are studied: an optical hemisphere and ellipsoidal shape window attached to a 3:1 ogive nose. A three dimensional thin-layer compressible flow solver is used to compute the flow field in front of the window and the window aerodynamic heating. A solution adaptive-grid scheme is applied to accurately compute the flow field and capture the bow shock. Noise-Equivalent-Temperature-Difference degradation due to 'background' noise of the hot window is derived and computed for 3 levels of array non-uniformity for a range of mean dome temperatures covering the whole supersonic regime. Acquisition range for a staring sensor is estimated for several maritime scenarios modeled by LOWTRAN code. Background photon flux distribution on an array generated by the hot dome is computed using radiation transfer methods using the dome temperature field obtained by computational fluid dynamic methods. It is found that array non-uniformity has a strong influence on the seeker performance. This study indicates that the non-uniformity of the dome temperature has significant influence on the array fixed pattern noise induced by dome emission and so in the seeker detection and tracking ability.
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