Impact of Radiation Degradation in CIS on Star Sensor’s Detection and Positioning Capabilities

Star sensors, high-precision instruments for spatial attitude determination, rely critically on the CMOS image sensor (CIS) for imaging. The performance of CIS degrades under space radiation, yet its impact on system-level performance remains insufficiently understood. This study conducted proton irradiation experiments (30 MeV) on CIS to analyze the degradation mechanisms of dark current, dark current non-uniformity, and quantum efficiency. Integrated into a star sensor system, the irradiated CIS showed degraded signal-to-noise ratio (SNR) under simulated star imaging. The effect of radiation-induced hot pixels on centroid positioning accuracy was also investigated, revealing that their impact depends on relative intensity and spatial distribution. This work provides a preliminary analysis of how device-level radiation effects translate to system-level performance degradation in star sensors.