EXTERNAL COMPARISON SATELLITE POSITIONS OBTAINED BY THE NETWORK OF PASSIVE CORRELATION RANGING OF GESTATIONARY TELECOMMUNICATION SATELLITES

Анотація

Network of passive correlation ranging contains of five stations located in Ukraine and Latvia. It has been created at the initiative of the RI “Mykolaiv Astronomical Observatory” to have independent means to track the future Ukrainian geostationary satellite “Lybid”. Regular observations of the geostationary telecommunication satellite “Eutelsat-13B” has being carried out by the network since February 2015. A catalog of daily orbital elements of the tracked satellite has been created using the network observations. The analytical model SGP4/SDP4 of satellite motion and a numerical model of integration of equations of satellite motion are used to determine the orbital elements. The numerical model takes into account the gravitational attraction of the Sun and Moon, and non-spherical Earth. Software of the orbital elements determinations has been developed by the RI “Astronomical Observatory” of the Mechnikov Odesa National University.

Satellite positions calculated using orbital elements from the catalog were compared with ones obtained using the NORAD space-track.org site and optical observations performed by the Ukrainian Network of Optical Stations. The satellite position comparisons were carried out only for time intervals of unperturbed motion of the satellite. The free motion time intervals were determined using the algorithm that had been tested using satellite owner data about the moments of satellite maneuvers. Herewith values of right ascension and declination were compared. Regular (mean) and random (standard deviation) values of the residuals are given in the report.