The image mapper plays a key role in the imaging process of the image mapping spectrometer (IMS), which is a snapshot imaging spectrometer with superiority in light throughput, temporal resolution, and compactness. In this paper, an accurate ray tracing model of the imaging units of the IMS, especially the image mapper, is presented in the form of vector operation. Based on the proposed model, the behavior of light reflection on the image mapper is analyzed thoroughly, including the precise position of the reflection point and interaction between adjacent facets. Rigorous spatial correspondence between object points and pixels on the detector is determined by tracing the chief ray of an arbitrary point in the field. The shadowing effect, which is shadowing between adjacent facets and blocking caused by the facets' side walls, is analyzed based on our model. The experimental results verify the fidelity of the model and the existence of the shadowing effect. The research is meaningful for comprehending the imaging mechanism of the IMS and facilitates the design and analysis process in the future.

中文翻译：

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基于图像映射器的成像系统的精确光线追踪模型。

图像映射器在图像映射光谱仪（IMS）的成像过程中起着关键作用，IMS是一种快照成像光谱仪，在光通量，时间分辨率和紧凑性方面都有优势。在本文中，以矢量操作的形式提出了IMS成像单元（尤其是图像映射器）的精确射线追踪模型。基于提出的模型，对图像映射器上的光反射行为进行了全面分析，包括反射点的精确位置和相邻小平面之间的相互作用。通过跟踪视场中任意点的主光线，可以确定目标点与检测器上像素之间的严格空间对应关系。阴影效果，即相邻小平面之间的阴影和小平面侧壁造成的遮挡，根据我们的模型进行分析。实验结果验证了模型的保真度和阴影效应的存在。这项研究对于理解IMS的成像机制是有意义的，并有助于将来的设计和分析过程。