风云二号卫星云图显示扫描辐射计存在红外杂散辐射，因此需要对光学 系统作进一步改进以减少杂散辐射。利用TracePro软件对该系统的红外杂散辐射的形成机理和入侵途径进行了仿 真和分析。基于分析结果对该光学系统的红外杂散辐射提出了几项有效抑制措施，并通过计算 系统的点源透过率(Point Source Transmittance, PST)函数对这些改进措施进行了评价。

Because the nephograms of FY-2 meterological satellite show that there exists stray infrared light in the radiometer, it is necessary to further modify the optical system used in the radiometer so as to suppress the stray infrared light. The generation mechanism and path of the stray infrared light in the optical system are simulated and analyzed by the TracePro software. On the basis of the analysis result, several measures which can be used to suppress the stray infrared light of the optical system effectively are proposed. Finally, these measures are evaluated by calculating the Point Source Transmission (PST) function of the optical system.