Research On Series High Dynamic Range Infrared Scene Simulation Technoligy

With the rapid development of infrared technology,the performance of the infrared detection system of the seeker has been greatly improved,but the current semi-physical simulation system cannot provide enough original image data,which affects the development of infrared guidance technology.In order to give full play to the role of the semi-physical simulation system and more accurately simulate high dynamic range scenes,more stringent standards are proposed for the performance parameters of its core device infrared scene simulator.This paper mainly studies the theory and method of improving the dynamic range of infrared scene simulation technology,and verifies the effectiveness of the method through imaging simulation.First,it introduces the definition of dynamic range,and introduces the common representation of dynamic range and the conversion between them.Then,the dynamic range of different infrared scene simulation technologies is analyzed and compared,and it is found that the dynamic range of the detector of the system unit to be tested is60 d B?96d B,while the current dynamic range of most simulation systems is less than60 d B.The analysis shows that there are certain limitations of the parallel superposition hybrid scheme to improve the dynamic range of the infrared scene simulator at home and abroad.Therefore,a series high-dynamic range infrared scene simulation scheme is proposed to effectively avoid the disadvantages of the parallel type.A combination of a pre-modulator and a second modulator to obtain a dark region with lower brightness to improve the dynamic range.In this scheme,the key components of the digital micro-mirror device(DMD)affecting the dynamic range are analyzed.Then,since the diffraction effect of DMD in the high dynamic range infrared simulation scheme is the primary factor affecting the dynamic range,its diffraction characteristics are analyzed.The DMD is simplified as a blazed grating,and the diffraction characteristics of the grating are used for theoretical analysis.In the infrared band 3?5?m,the scalar diffraction theory is used to derive the diffraction intensity distribution and diffraction efficiency formula of DMD.In the infrared band 8?12?m,the strict coupling wave theory based on the differential method in the vector diffraction theory is used,and the multilayer approximation method is used The blazed grating is simplified as a multi-layered rectangular grating with different duty cycles and the same period.The transmission matrix method is used to solve the problem of numerical instability in the multi-layer structure solution.The transmission and reflection diffraction efficiency formulas of DMD under different polarization states TE and TM are derived.Finally,the established scalar diffraction model and vector diffraction model are calculated,and according to the established diffraction model,the common infraredscene simulation scheme and the serial high dynamic range infrared scene simulation scheme in this paper are separately imaged and simulated in different wave bands.Compared with the common scheme,the dynamic range of the internal series scheme's dynamic range is up to 12?16d B,which verifies the effectiveness of the scheme;and the principle system scheme verification is completed through the ZEMAX non-sequential mode,which effectively reduces the micro lenses and lenses.The stray light effect caused by the spontaneous radiation of the group effectively increases the dynamic range by 0.06?0.34 d B.