空间目标褶皱材质BRDF建模方法

Bidirectional Reflectance Distribution Function Modeling Approach of Space Objects’ Fold Material

由于受到外界环境的影响,卫星表面常常呈不规则的褶皱状,这会对其光学特性产生一定影响。故空间目标光学特性建模研究需要将表面褶皱考虑在内,但大量褶皱面元的存在会导致运算量剧增。在此将褶皱看作一种材质,提出基于宏观光学散射截面测量的双向反射分布函数(BRDF)生成方法,求得褶皱材质的BRDF数据,进一步利用误差逆传播(BP)神经网络建立了褶皱材质的BRDF模型,代替了复杂的褶皱建模过程,大大简化了计算,在保证精度的前提下解决了其实时性差的问题。同时,通过实验与仿真相结合的方式,将所设计的BRDF模型与传统BRDF模型进行对比,验证了所设计模型的误差远小于传统模型。

Due to the influence of the external environment, the satellite′s surface is often irregularly folded, and these folds have some influences on the optical properties. So folds need to be taken into account in the modeling of the optical characteristics of space objects. However, a large number of surface cells in fold surface will lead to a dramatic increase in computational complexity. This paper considers pleats as a kind of ’material’. A method based on macroscopic optical scattering cross section measurement is proposed to obtain the bidirectional reflectance distribution function(BRDF) data of the fold material. Furthermore, the error back propagation neural network is used to establish BRDF model of fold material, which replaces the complex modeling process of folds and greatly simplifies the calculation. The problem of poor real-time performance is solved under the acceptable accuracy. By combining the experiment with the simulation to compare the BRDF model designed in this paper with the traditional BRDF model, it is verified that the error of the model designed in this paper is much smaller than that of the traditional model.