Analysis And Research On Aberration Correction Of Fairing Based On Rotationally Symmetric Aspheric Surface

With the progress of the times,infrared air-to-air missiles have occupied an increasingly important position in modern scientific and technological life.One of the core components of the infrared air-to-air missile is the infrared seeker.As the fairing at the forefront of the seeker,it is even more critical.Early traditional fairings used spheres or hemispheres,but after research,it was found that these two shapes of fairings do not have good aerodynamic characteristics and are not suitable for high-speed flight.In order to further improve the overall aerodynamic performance,the conformal optical system replaces the spherical fairing with a streamlined fairing.Although the use of the streamlined fairing reduces the flight resistance,it is due to its own Symmetry introduces higher-order aberrations,which greatly reduces the imaging quality.Therefore,it is very important to correct the aberration caused by the streamlined fairing and complete the design of the conformal optical system.In the context of the above,this article studies the following:First,four streamlined fairings with low resistance in aerodynamic research were established: ellipsoidal fairing,parabolic fairing,hyperboloid fairing and von Carmen curved fairing;under different target fields of view,Respectively analyze the aberration characteristics of the four face fairings;at the 0 ° target field of view,the effect of the change of the aspect ratio on the aberration of the four face fairings is analyzed by changing the aspect ratio;By changing the shape of the inner surface of the fairing,the effect of the number of aspheric surfaces on the inner surface of the fairing in aberration correction is obtained.Secondly,according to the different aberration characteristics of the four surface fairings,appropriate correctors are selected respectively,and the principle analysis and theoretical derivation of the two aberration correctors selected in this paper are carried out.Among them,a fixed aberration corrector based on the Wassermann-Wolf curved surface of the independent joint expansion was selected for the ellipsoidal fairing;for the other three fairings with larger eccentricity,the moving image of the rotating Zernike double optical wedge was used The difference corrector achieves a better correction effect.Finally,the corresponding conformal optical system design was completed for the four surface fairings respectively,and the corresponding image quality evaluation was carried out on this basis.In addition,a relatively comprehensive horizontal comparative analysis was completed for the characteristics of different face fairings and the difficulty of correction.The results show that it is more reasonable to use different types of correctors for different surface fairings;the final MTF curve of each conformal optical system design can meet the requirements for use;only in the parabolic fairing and hyperboloidal rectification In the design of the conformal optical system of the mask and the von Carmen curved fairing,due to the use of a motion aberration corrector,the scanning field of view is greatly reduced,and the disadvantages of image quality and target field of view cannot be considered at the same time.