非分辨空间目标光谱双向反射分布函数的实验室平行测量

Parallel Measurement of Spectral Bidirectional Reflectance Distribution Function of Non-resolved Space Objects in Laboratory

为了克服非分辨空间目标识别研究中外场观测和计算机仿真手段的局限性,采用实验方法模拟了天基光照场景,用仪器和技术平行类比望远镜观测时光源-目标-探测器方位,并测量了某高保真卫星模型的光谱双向反射分布函数.分析了空间目标光谱散射模型、实验场旋转轴系和环境模拟设备布局.根据在轨卫星的轨道和姿态建立了外场观测几何到室内5轴旋转系统的角度映射关系.利用该关系控制旋转系统实现了对某卫星过境观测的平行模拟,并对目标混合光谱进行了测量和定标.实验结果发表明:目标光谱数据中存在"闪光"和峰值波长迁移现象;旋转系统各轴定位精度为0.5°,光谱数据相对测量误差为0.018%.该方法能实现空间目标观测的全角度平行模拟,测量结果为非分辨目标外形、材料、旋转等特性的识别提供参考.

In order to overcome the limitations of telescopic observation and computer simulation in space object identification,experimental methods were utilized to emulate space-based illumination conditions using equipment and techniques that parallel telescopic observations and source-target-sensor orientations,while the spectral bidirectional reflectance distribution function of a high fidelity satellite model was characterized.First,the space object spectral scattering model,the axes of rotation system and equipments layout were analyzed.According to real on-orbit attitude and orbital elements of the satellite,angular relationship between the observing geometry and the five-axis rotation system werebuilt.Finally,in the light of this relationship,parallel emulation during a satellite passage was processed,the rotation system with spectrophotometric data was measured and calibrated.Experimental results focus on luminance glint and peak wavelength drifts shown in the spectral data.The control precision of the rotation axes is 0.5°,and relative precision of spectral measurement is 0.018%.Experimental results indicate that the proposedmethod can realize parallel implementations of space objects observation and serve as a reference for study of shape,materials and rotation condition of non-resolved space objects.