Research And Design Of Optical System For Infrared Search And Track Using Spacial Modulation

As the Infrared Search and Track System (IRST) develops, it is demanded that theinfrared optical systems have wide field-of-view (FOV) and excellent resolution.However, limited by the scale of the infrared focal plane array (IR FPA) and theprogress of signal processing, it is difficult for infrared staring systems to acquire wideFOV and high resolution at the same time. This thesis provides an infrared system forpoint target detection with wide FOV and high resolution using spatial modulation,which can be used in land-based, airborne or ship-borne IRST systems and infraredalarming systems. The structure and parameters are analyzed in detail including thespatial modulation staring system and the foveal enhanced system. The designing resultsand the image quality meet the spatial modulation and imaging requirement. The maintasks are:Firstly, the theory of spatial modulation is deeply studied. The method howchopping reticle modulates and the signal’s demodulation process are fully discussed,which provides theoretical basis for determining the structure and parameters of totaloptical system.Secondly, some basis parameters are selected, such as the waveband, theparameters of IR FPA and the reticle. The structure and parameters of total opticalsystem and its each part are analyzed and finally determined using spatial modulationtheory.At last, according to different structures and parameters of each system, all systemsare designed and optimized by software CODE V. Then, all systems are integrated intothe total system for overall optimizing. The designing results and the image quality meetthe requirement.