利用有限差分法计算空间目标红外特征

空间目标的红外辐射特性是对空间目标进行探测与识别的重要依据.首先分析了空间目标与外界环境的热交换关系,确定了目标表面的边界条件,推导出边界单元的有限差分形式,针对空间目标的遮挡问题.开展了判断方法的讨论,为准确计算目标的表面温度场奠定了基础.其次利用有限差分法求解其导热微分方程,获得了目标表面温度场分布特性;将总红外辐射分解为自发辐射和反射辐射两部分,分别给出了计算自发辐射强度和反射辐射强度的计算式.最后以某空间目标为例,利用数值方法计算表面温度场,并在此基础上计算了红外辐射强度的空间分布,对计算结果进行了分析.

Calculations of infrared radiation of space target using finite difference method

The infrared radiation characteristic is the important basis for detection and identification of space target.Firstly,the relationship of heat exchange of space target with the external environment was analyzed,the boundary conditions of target surface was determined,the finite difference equations of boundary units were derived,and the judging method was discussed for the problem of occlusion of space target,which laid the foundation for calculating the surface temperature field of the target exactly.Secondly,the finite difference method(FDM)was used to solve the heat conduction differential equations,the distribution characteristic of surface temperature field was obtained.The total infrared radiation was divided into the spontaneous emission and the reflection radiation,and the formulas for spontaneous and reflection radiant intensity were given respectively.Take one space target as an example,the numerical method was used to calculate surface temperature field,the distribution of infrared radiation intensity was calculated,and the calculation results were analyzed finally.