A CCD/CMOS telescope digital twin for Space Situational Awareness

Space Situational Awareness (SSA) is the process of gaining and maintaining knowledge of space objects and their operational state. Much of the data that powers SSA activities is collected as images taken by optical sensors. Ground-based image acquisition is a dynamic process that is dependent on the object being imaged, as well as time-varying atmospheric and celestial conditions, and the geographic and optical properties of the optics and its sensor. In this work, we develop a digital twin model of image acquisition focusing on high photometric accuracy for optical ground stations using charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) sensors. This work provides a high-fidelity photometric model for space objects and background stars and an approach to combine these signals into high-quality synthetic images. Simulated images produced with our model are compared and validated against observations from the Purdue Optical Ground Station (POGS) and the Zimmerwald Multiple Applications Instrument telescope (ZimMAIN). The presented model may be applied to design surveys for operational telescopes or to generate synthetic image datasets for training machine learning models for detecting and tracking space objects.