太阳同步轨道卫星光学特性

为了分析太阳同步轨道卫星的光学特性,对FY-1卫星的可见光和红外波段光学信号进行了仿真计算和模拟试验验证.通过对外部辐射及内部热源的分析,计算了卫星的温度场,采用随机起伏表面算法模拟表面覆盖材料外表面,通过阴影遮挡判断及双向反射分布函数(BRDF, Bi-directional Reflectance Distribution Function)模型计算卫星对外部辐射的反射特性,编程计算得到在可见光0.4~1.0μm和红外8~14 μm,14~16 μm波段下卫星的光学特性.结果表明红外辐射亮度与表面温度相关,8~14 μm最大约90 W/(m²·sr)、14~16 μm最大约20 W/(m²·sr).空间可见光辐射强度具有明显的镜面反射效应,卫星主体峰值2 200 W/sr.通过地面模拟测量空间目标的温度和红外辐射验证了温度及红外辐射仿真计算模型,可见光辐射强度仿真计算结果与地面模型卫星测量结果误差在20%以内.

Optical properties of sun synchronous orbit satellite

Optical characteristics of sun synchronous orbit satellite FY-1 were studied by simulation and experimental verification in visible and infrared band. Taken as input in calculation of infrared emission, temperature field on satellite surfaces were solved according to the radiation flux of outer sources. Undulating algorithm was used to describe appearance of the surface material. Reflection from satellite was based on judgments of shadow and bi-directional reflectance distribution function (BRDF) of surface materials. The signatures of FY-1 satellite were calculated and analyzed in infrared and visible band. The results show that infrared luminance of satellite surface is related with temperature. The maximum value is 90 W/(m²·sr) in 8~14 μm band, and 20 W/(m²·sr) in 14~16 μm band. The reflected light intensity show remarkable specula reflect. Maximum value is 2 200 W/sr. The measurement relative error is less than 20%.