建立中段弹道目标的简化辐射模型和基于点扩散与拖尾的红外焦平面模型，结合目标群中各目标的运动位 置和空间目标投射到二维焦平面位置坐标的计算，仿真天基低轨红外传感器对中段弹道目标群的成像.分析仿真 结果，发现中段弹道目标群的存在对天基红外传感器的目标探测与跟踪提出了新的要求，并给出一些解决途径.

The simplified radiance model of midcourse ballistic target and the infrared focal plane model based on point spread function and target tail were presented. By integrating the calculations for target space position and the position in 2D focal plane projected from 3-D space， the imaging of midcourse ballistic object target complex in space-based infrared sensor was simulated. By analysing the simulation results， it was found out that the midcourse ballistic object target complex would give rise to new challenges for detection and tracking techniques of space-based infrared sensor. The methods to solve these challenges were given here.