Modeling And Simulation Of Infrared Seeker Imaging System With Aero-dynamic And Laser Jamming Effects

Today,the infrared imaging seeker has been widely used in air-to-air,air-to-ground,groundto-air,ground-to-ground and many other diverse tactical weapons.Recently,with the situations of the international warfare changing,the working environment of the infrared seeker has become increasingly complex: the aero-dynamic effects of the optical dome and the laser interference have been proved to be the noticeable reasons for imaging quality of the infrared seeker.It is necessary to launch the research on modeling and simulating the aero-dynamic effects and laser jamming effects on infrared seeker,for the reason that it can provide a model basis for the simulation study of the high speed missiles in complx battlefields;additionally,it can also provide a strong data support for the engineering research aiming at improving the anti-interference ability of the infrared seeker;therefore,it shows great significance in engineering practical use.According to the energy transmission law and signal transfer process,the features and characteristics of the imaging process for the infrared seeker has been modeled and simulated in this thesis;furthermore,with the infrared radiance(IR)transmission model of the optical dome built,characteristics in imaging results caused by aero-dynamic effects have been simulated;in addition,on the principle of charge transfer process in CCD detector,the crosstalk patterns in imaging results caused by laser have been studied and simulated.The main works of this thesis are as follows:1.A modelling and simulation process of the imaging characteristics for the infrared imaging seeker has been accomplished.Firstly,based on the structure and imaging mechanism of the infrared seeker,the signal transfer process and the imaging features in optical system,detector and signal processing system of the infrared seeker have been analysed.Secondly,the optics model of the infrared seeker has been built with Zemax(an optical design and imaging simulation software),and the imaging effects of the optical system have been simulated with the MTF data output by Zemax.Thirdly,with the imaging demand of the high-performance infrared seeker system,the photoelectric conversion process has been analyzed;furthermore,a physical model of the infrared detector has been built;and the imaging charecteristics caused by different detector parameters have been simulated;the main detector parameters include: the detector integration time,non-uniformity,detector noise,spatial and time filter effects.Lastly,according to the A/D(analog-to-digital)conversion and equivalent filtering effects of the circuit,the typical effects of the signal processing system have been simulated.2.The imaging charecteristics of the infrared seeker under aero-dynamic effects have been modeled and simulated.Firstly,the temperature distribution fields both of the optical dome and the dome window have been simulated by Fluent(a fluid simulation software);Secondly,on the basis of the relation between refractive index and temperature,a gradient refractive index model of the optical dome has been built by Zemax;Lastly,with the PSF data output by the optical system of the infrared seeker,the imaging characteristics caused by aerodynamic effects have been simulated;furthermore,the aero-dynamic effects in different flight conditions have been analyzed.3.The crosstalk effects of laser jamming on infrared seeker have been simulated.Firstly,based on the transfer law of saturated charges when laser jams CCD detector,a model of laser crosstalk effects has been conducted;secondly,with the power density and incident angle changes,different imaging characteristics of laser jamming on infrared seeker have been simulated;lastly,with imaging evaluation methods,the simulated images with different laser jamming conditions have been analyzed and evaluated.