Stray light analysis and suppression of high-resolution camera line-of-sight variation real-time monitoring system (LoS Var RTMS)

Abstract

Due to environmental disturbances during emission and operation processes, the line-of-sight of a high-resolution camera is highly prone to variation, resulting in a significant decrease in image positioning accuracy. To address this issue, we propose a line-of-sight variation real-time monitoring system (LoS Var RTMS). A full-link active optical monitoring system is established using laser, and a high-resolution camera is coupled to a star tracker, thereby enhancing the on-orbit calibration and image positioning accuracy of the camera. However, the high-resolution camera LoS Var RTMS belongs to a high stray light sensitivity system. Stray light entering the star tracker from the high-resolution camera through the relay reflective system can significantly affect the imaging of the star tracker, leading to the failure of the monitoring system. Therefore, a comprehensive and accurate analysis of the stray light propagation path in the monitoring system is necessary to ensure its normal operation. In response to this issue, this article proposes a stray light analysis method based on the surface subdivision method, and utilizes inverse ray tracing to meticulously analyze the propagation path of stray light. Additionally, to address the impact of stray light on laser light in the LoS Var RTMS, an inner baffle polarization filtering system is designed to effectively suppress the influence of external strong stray light on the monitoring system. The results demonstrate that the stray light analysis method based on the surface subdivision method not only enhances the integrity and accuracy of the analysis of stray light propagation paths within the monitoring system, but also significantly improves the precision of stray light analysis. It provides a reference for the analysis of stray light in high stray light sensitive systems. Moreover, the design of the inner baffle polarization filtering system effectively distinguishes between lasers and stray light, suppressing stray light within the high-resolution camera LoS Var RTMS and ensuring its normal operation.