成像系统仿真对光学遥感器的论证、设计和在轨性能预估具有重要意义。场景作为遥感的对象, 其特性的表征和模拟对仿真结果有直接影响。场景特性难以全面表征, 针对光学遥感及其应用最为关键的几何、光谱和辐射特性, 提出一种基于光场理论的数字场景仿真方法。以包含空间坐标、方向、波长、强度的全光函数作为数字场景仿真的表征参数, 建立了涵盖太阳直射、天空漫射和背景反射等因素的数字场景入射辐照度场模型, 以及考虑方向反射特性的数字场景出射辐亮度场模型, 并基于简单场景对模型进行分析和验证。该方法能够为成像系统仿真及新型载荷研制提供包含多种特性的数字场景模型。

The simulation of the imaging system is very important to the demonstration, design and performance forecast of the optical remote sensing detector. As the remote sensing object, characterization and modelling of the scene will affect the simulation results directly. Aiming at the crucial geometry, spectrum and radiance characters, a digital scene modelling method based on the optical field theory was proposed. Using the plenoptic function comprised of geometrical coordinates, direction, spectrum and intensity, irradiance field onto the scene surface was modelled including the direct solar radiance, skylight radiance and reflected background radiance. With directional reflectance character of the surface, radiance field leaving the scene surface was also modelled. A simple small 3D scene was created to validate these models. The proposed method will provide digital scene model with multiple characters for the imaging system simulation and the new-style detector development.