Wide-Field Space Debris Detection And Characterization Through RGB Digital Imaging

With the increasing population of space debris, the accuracy of space surveillance and tracking products is crucial to ensuring the safe usage of Earth's orbits. Key applications include collision avoidance, reentry predictions, and fragmentation event analysis. However, single telescopes, even those with excellent performance, have limited observation time and can track only a few objects per night. To address this limitation, innovative optical systems have been developed in recent years, such as the SURveillance GEostationary (SURGE) system, which has been operated at Sapienza University of Rome’s S5Lab since 2021. SURGE is a wide-field optical system based on commercial reflex cameras, allowing observations over large portions of the sky, with a field of view extending up to tens of degrees for single camera. A smaller version, miniSURGE, is also operational. Designed for monitoring the geostationary belt, these systems offer a significant advantage over traditional telescopes due to their wide field of view, enabling the simultaneous observation of multiple objects and the acquisition of millions of astrometric measurements during each observation session. Additional advantages include a compact design that requires minimal maintenance, portability, and cost-effectiveness due to the use of commercial components. Furthermore, the imaging sensors allow simultaneous RGB observations, enabling color photometry. This paper discusses the performance and capabilities of the system, along with methodologies to mitigate its main limitations, such as small optical aperture, lens distortion, electronic noise, low quantum efficiency, and time synchronization challenges, factors that generally reduce image and measurement quality. In particular, the time calibration procedure is discussed in detail due to its strong correlation with measurement quality and accuracy. The results obtained with SURGE and miniSURGE include orbit determination of both cataloged and non-cataloged objects, enabling simultaneous monitoring of multiple targets. Additionally, light curves in RGB and grayscale are presented, providing valuable data for object characterization. The observation activities and results discussed in this paper support the ASI delegation to the IADC within the framework of the ASI-INAF agreement.