Analysis of Stray Light in Inter-satellite Beacon-less Laser Communication and Its Influence on Acquisition Probability.

Satellite optical communication offers numerous benefits, such as high communication rate, good confidentiality, and lightweight terminal. Beacon-less optical capture technology utilizes narrow beam for scanning, which helps to improve capture performance. However, the capture probability of the tracking link is affected by factors such as stray light and platform vibration, which can decrease signal-to-noise (SNR) ratio, results in missed scans, and reduced the coverage rate. In this paper, the stray light propagation model is established based on the irradiance theory, and the solar transit phenomenon and the earth background radiation are modeled and analyzed. The simulation results show that reasonable orbit design can avoid solar transit and the earth stray light can reach to 10-8W which is equivalent to the signal light intensity. On the other hand, the model of the influence of SNR and vibration on acquisition performance is established, and the changes of scanning coverage, uncertain area coverage and detection probability under the coupling influence of stray light intensity and vibration are analyzed. The results show that the sensitivity of vibration to the overall acquisition probability is greater under the coupling influence. In addition, the influence of stray light not only depends on the SNR intensity, but also related to the selection of threshold it.