Large Data Collection Through Innovative Optical Systems for Angles-Only Orbit Determination

Orbit Determination (OD) is the process that allows, starting from an available set of measurements, the estimation of the dynamic state of an object that orbits around a central body. Given the raising number of active satellites and space debris in both Geostationary (GEO) ring and Low Earth Orbit (LEO) orbits, a continuous and accurate monitoring of these objects is strictly necessary and increasingly important. Furthermore, in the framework of the Space Traffic Management (STM) an accurate optical observation system and a precise OD procedure are fundamental in the orbiting object’s catalogue maintenance and mitigation services. Nowadays, the OD procedure can be carried out using optical measurements, in terms of Right Ascension (RA) and Declination (Dec), obtained pursuing the sidereal tracking observation method and using a Charge Coupled Device (CCD) sensor with a narrow field of view. However, this classical method allows to acquire only a few numbers of measurements for each satellite passage. The Sapienza Space Systems and Space Surveillance Laboratory (S5Lab) research team has years of experience in Space Surveillance and Tracking (SST) through optical observations, with a network of telescopes and observations systems that implement not only the classical methods, but also new technologies and methodologies. The purpose of this paper is to investigate the OD for all orbital regimes, performed with the newest data acquisition methods and systems. Regarding LEO objects observation, the last generation sensors scientific Complementary Metal-Oxide Semiconductor (sCMOS) are used. These sensors are characterized by a high frame-rate acquisition that allows to collect a large amount of data for an object during a single passage above the observatory, that is using the angles only short arc optical OD procedure. Instead, for GEO objects a fixed large field of view is used. In this way the GEO satellites are immediately discernible in the frame by their near circular shape, due to the fact that these satellites remain in the same position during the whole exposure. This optical system allows to obtain a huge number of measurements spread in a time span of several hours, that is the whole observation night. The OD results are then compared with the ones obtained with classical optical observations to validate the OD procedure performed with these new systems data. Moreover, all the obtained measurements are previously calibrated to verify the accuracy of the acquisition systems.