Influence of Indirect Solar Irradiance on Satellite Observation

With the development of Space Domain Awareness (SDA), satellites’ optical characteristics are becoming attention-grabbing. Sunlight was usually considered the only light source for the satellite observation. However, in the actual observation, researchers have found that earthshine and moonlight would increase errors of the observation results, which could greatly influence the estimation of the satellite’s state. In order to avoid this disadvantage, we propose an observation strategy by an accurate theoretical analysis. Firstly, we propose an accurate earthshine model, which has considered the earth’s volume and the continuous observation. Then, we explore the earthshine and moonlight’s impact on satellite observation results and find that this impact varies with the attributes of satellites. Furthermore, we analyze the law of this impact and establish a connection between the law and the observation geometry. Finally, a Period Contribution model is proposed to provide a corresponding observation strategy to reduce the influence of earthshine and moonlight. The model has statistically analyzed the effective time of Indirect Solar Irradiance.