Optical campaign for low Earth orbit satellites orbit determination

After some years of observations of the geostationary ring, the Group of Astrodynamics of the University of Rome “La Sapienza” (GAUSS) performed in 2005 a test optical campaign addressed to low Earth orbit satellites orbit determination. The objects Cosmos 1833 and Cosmos 2227 R/B (rocket body), chosen among the brightest, have been photographed by Collepardo Automatic Telescope equipped with a 40 cm Ritchey-Chrétien optical tube with focal reducer and a STL-1001E 1k×1k CCD (Charge Coupled Device). The field of view (FOV) exceeded 1°. Various orbit determination methods, well known in the literature, have been studied in order to compare their capabilities: orbit determination based on the null eccentricity hypothesis, classical methods for the state determination from angles only and real-time filtering for updating the elements were tested and their results compared. In all cases a priori information were not exploited.