A simulation method for stellar and target images based on the CODEV optical model

Abstract Long-distance target acquisition is a critical challenge in small celestial body exploration. Onboard acquisition software identifies and captures the target by leveraging the variation in the observed brightness of the small celestial body with relative distance and its relative motion characteristics against a stellar background. This paper proposes a simulation method for stellar and target images based on the CODEV optical model. For target brightness simulation, the HG model is enhanced by incorporating the target’s photometric variability and the camera’s color index correction. For image generation, the optical model of the camera is utilized, and ray tracing via CODEV ensures precise simulation of the imaging rays. Furthermore, the detector’s photoelectric parameters are applied to accurately simulate the photoelectric conversion process, ensuring that the generated images are consistent with the imaging characteristics of the actual instrument. A comparison between the simulated and real images shows that the positional difference of star points is approximately 10 pixels, while the energy and brightness distribution of the star points are nearly identical.