The LAser raDAR (LADAR) system designed in this study shows a ghost pattern around the object image when operated. The system contains 4 wedge prisms, each with different rotational directions and speeds. Therefore, an efficient and thorough analysis method was established. Ray path analysis was performed, and categorized, for every instantaneous case sampled using a backward ray tracing method. The rays' flux and directions were accumulated according to their path histories. This backward ray tracing was performed repeatedly with different neutral density (ND) filter orientations, until no measurable ghost radiance remained in the field of regard (FOR): a tilt angle of 5°. The ND filter was replaced with a mechanical vignette. Subsequently, the ghost flux was 21% of the total accumulated point cloud, coinciding with the actual measurement of 19%. The final image has significantly improved resolution and shows no ghost reflections where they were previously.

中文翻译：

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主动激光测距系统的Risley棱镜扫描仪使用后向光线路径分析抑制重影辐射。

本研究中设计的LAser raDAR（LADAR）系统在操作时会在物体图像周围显示出幻影图案。该系统包含4个楔形棱镜，每个楔形棱镜具有不同的旋转方向和速度。因此，建立了一种有效而彻底的分析方法。使用后向光线跟踪方法对采样的每个瞬时情况执行了光线路径分析并将其分类。光线的通量和方向是根据其路径历史累积的。以不同的中性密度（ND）滤镜方向重复执行此向后光线跟踪，直到在视场（FOR）中没有可测量的幻影辐射：倾斜角度为5°。ND滤镜被替换为机械装饰图案。随后，幻像通量为总累积点云的21％，与实际测量值的19％吻合。最终图像具有显着提高的分辨率，并且在以前的位置没有显示任何鬼影反射。