空间群目标的红外辐射与散射特性研究

发布时间：2018-03-26 09:00

本文选题：地球红外背景　切入点：空间目标　出处：《西安电子科技大学》2015年硕士论文

【摘要】：在现代,空间环境中的各种飞行器对军事和民用都起着越来越重要的作用,而对这些空间目标的识别和探测也将有更大的意义。空间目标的红外特性是在对其进行探测和识别时的一个重要判断标准,所以需要进行相关研究。本文以空间目标中的弹头和诱饵目标为主要对象,研究了目标的自身红外辐射特性和对背景辐射源的红外散射特性。本文的主要内容有:1、研究了空间目标的红外背景辐射源,利用MODIS卫星的陆地、海洋和云顶产品数据,建立了不同时间地球表面和云顶温度分布图及地球表面发射率分布图。通过获得温度场和发射率数据,便可以建立在3~5μm和8~12μm两个红外波段的辐射亮度模型。因为云顶的高度影响着云的性质,所以建立了云顶高度图,分析了云顶的高度分布特征。2、地球表面辐射和云顶辐射传递到空间目标时,大气会对其产生衰减,同时大气自己也会向外发出辐射,利用MODTRAN计算软件对这两部分进行了计算和分析。针对空间目标的特点,利用一种多项式拟合的方法对MODTRAN计算得到的大气透过率和路径辐射数据进行了处理,得到了其关于观察角的拟合函数,从而简化计算,并更容易编程实现。利用一种大气透过率的工程算法,获得云顶到目标之间的透过率。3、确定空间目标接收到的辐射来源,利用目标的节点热平衡方程,得到了目标表面的温度场,建立了其在3~5μm和8~12μm两个红外波段的自身红外辐射场。对分别利用角系数法和地球面元法计算得到的目标温度进行了对比。分析了目标在是否有自旋、不同高度、不同目标形状等情况下的温度场和红外辐射场的变化情况。4、为了计算空间目标对太阳、地球和经过地球反射的太阳辐射的散射,介绍了一种利用基尔霍夫法近似计算不同材料在红外波段的双向反射分布函数的方法。在此基础上利用不同方法计算了空间目标对这三种背景在两个红外波段的积分散射强度。讨论了目标表面为朗伯面和非朗伯面以及目标对不同背景辐射源等情况下的积分散射强度。并把建立的真实地球背景,代入到计算中,使计算更加真实。5、在分析单个目标后,因为弹头和诱饵是在一起飞行的,所以分析群目标的情况。研究了由两个目标和三个目标组成的群目标时的整体温度特性和整体红外特性,并与单个目标的情况进行了对比。本文建立了空间目标的红外辐射背景模型,并对单个和多个情况下的空间弹头和诱饵目标的红外特性进行了分析,为目标探测和真假目标的识别提供了理论支持。
[Abstract]:In modern times, aircraft in the space environment play an increasingly important role in both military and civilian life. And the recognition and detection of these space targets will be of greater significance. The infrared characteristics of space targets are an important criterion for their detection and recognition. So we need to do some research. This paper takes the warhead and decoy target in space target as the main object. The infrared radiation characteristics of the target and the infrared scattering characteristics of the background radiation source are studied. The main contents of this paper are: 1. The infrared background radiation source of the space target is studied. The data of the land, ocean and cloud top products of the MODIS satellite are used. The temperature distribution map of the earth's surface and cloud top and the emissivity distribution of the earth's surface are established at different times. The temperature field and emissivity data are obtained. The radiance luminance model can be established in the infrared bands of 3 ~ 5 渭 m and 8 ~ 12 渭 m. Because the height of the cloud top affects the nature of the cloud, the height map of the cloud top is established. The height distribution characteristics of the cloud top. 2. When the earth surface radiation and the cloud top radiation transfer to the space target, the atmosphere will attenuate it, and the atmosphere itself will emit radiation. The two parts are calculated and analyzed by MODTRAN software. According to the characteristics of space objects, the atmospheric transmittance and path radiation data calculated by MODTRAN are processed by a polynomial fitting method. The fitting function of the observation angle is obtained, which simplifies the calculation and makes it easier to program. Using an engineering algorithm of atmospheric transmittance, the transmittance between the cloud top and the target is obtained, and the source of radiation received by the space target is determined. Using the nodal heat balance equation of the target, the temperature field of the target surface is obtained. Its own infrared radiation field in the infrared bands of 3 ~ 5 渭 m and 8 ~ 12 渭 m is established. The target temperature calculated by the angular coefficient method and the Earth panel method is compared, and whether the target has spin or not at different altitudes is analyzed. The variation of temperature field and infrared radiation field in different target shapes. 4. In order to calculate the scattering of solar radiation from space targets to the sun, the earth and the reflected solar radiation through the earth, This paper introduces a method of approximate calculating the bidirectional reflectance distribution function of different materials in infrared band by using Kirchhoff method. On the basis of this, different methods are used to calculate the spatial target pairs of these three kinds of background in two infrared bands. The integral scattering intensity is discussed when the target surface is Lambert surface and non-Lambert surface, and the target has different background radiation sources. Into the calculation, which makes the calculation more real. 5, after analyzing a single target, because the warhead and the decoy fly together, So we analyze the situation of the cluster targets. We study the global temperature and infrared characteristics of the group targets, which are composed of two targets and three targets. The infrared radiation background model of space target is established, and the infrared characteristics of space warhead and decoy target in single or multiple cases are analyzed. It provides theoretical support for target detection and identification of true and false targets.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN211

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