典型卫星表面材质的近红外干涉光谱反演

Characterization of Typical Satellite Surface Material Using Near-Infrared Interference Spectra

为研究空间碎片表面材料发生镜面反射时的光谱特征,采用光纤光谱仪联合高精度测角光度计,测量了4种典型空间碎片材质在多种入射角下的可见-短波红外光谱反射率,发现三结砷化镓电池片和聚酰亚胺包覆膜的镜面反射光谱在近红外波段(1000~1800 nm)出现了明显的等倾干涉光谱条纹。进一步分析表明,该光谱条纹由空间材质本身的多层工艺结构特性引起,并运用相关分析法建模计算求得砷化镓层厚度为5.5189μm,近红外折射率为3.4724;聚酰亚胺层厚度为24.2106μm,近红外折射率为1.7074,反演结果与材质标称参数相符。实验结果表明:近红外谱段镜面反射光谱特征可用于多层结构的空间碎片材质的厚度、折射率等工艺特性反演,该方法可为卫星材质精细辨识提供新的研究思路。

To study the spectral characteristics of space debris surface materials when specular reflection occurs,the visible to shortwave-infrared spectral reflectance of four typical space debris materials at various incident angles is measured with a high-precision goniometer and a fiber optic spectrometer.It is found that the specular reflection spectra of the gallium arsenide(GaAs)cell and the polyimide coating film show significant isoclinic interference spectrum fringes in the near-infrared band(from 1000 nm to 1800 nm),which is probably caused by the multi-layer structure of the materials.A model is established and calculated for further analysis by using correlation methods.The results show that the thickness of the GaAs layer is 5.5189μm with anear-infrared refractive index of 3.4724,and the thickness of the polyimide layer is 24.2106μm with anear-infrared refractive index of 1.7074,which are consistent with the nominal characteristics of the materials.The experimental results indicate that the near-infrared reflectance spectral characteristics can be used to retrieve the process characteristics of multi-layer space debris materials such as thickness and refractive index.The methods used in this article may be applicable to the fine identification of space debris materials.