基于光线追迹的长线列摆扫式热像仪在轨几何成像仿真方法

针对卫星发射前在轨数据缺乏导致的无法进行成像质量评估、链路分析及几何处理算法验证等问题,提出了一种基于光线追迹的长线列摆扫式热像仪在轨几何成像仿真方法.首先根据光学系统结构及成像特点,构建了长线列摆扫式热像仪严格几何定位模型;然后,基于姿轨仿真数据、DOM和DEM辅助数据,通过光线追迹及重投影算法实现了像元视矢量的空间...

In-orbit geometric imaging simulation based on ray-tracing for long-linear-array and whisk-broom thermal infrared imager

In order to solve the problems of image quality evaluation,imaging link analysis and subsequent processing algorithm verification due to the lack of in-orbit data before satellite launch,an in-orbit geometric imaging simulation method for long-linear-array and whisk-broom(LLAWB)thermal infrared imager(TIRI)based on ray tracing is proposed.Firstly,according to the structure and imaging characteristics of the optical system,the rigorous geometric imaging model of the LLAWB TIRI is constructed.Then,based on the simulation attitude and orbit parameters,auxiliary DOM and DEM data,the spatial projection and imaging simulation of pixel visual vector are realized by ray tracing and re-projection algorithm.Finally,a geometric calibration method based on"generalized"correction matrix is proposed to modify the positioning model and improve the positioning accuracy of simulation images.Experimental results show that the proposed method can be used to simulate the geometric imaging of any orbit position for the LLAWB TIRI,and the positioning accuracy of the simulation image is better than two pixels after calibration.This research provides a new idea for in-orbit geometric imaging simulation of space optical payloads,and is of great significance to the error analysis,geometric positioning and calibration of imaging links.