Sun noise measurement at low Earth orbiting satellite ground station

The project "MOST" (microvariability and oscillations of stars) is a Canadian micro satellite space telescope mission. The micro satellite carries a Rumak-Maksutov telescope with an aperture of 15 cm. The size of the satellite is 65 cm times 65 cm times 30 cm and the mass is about 65 kg. The goals of the mission are to analyze the inner structure of stars, set a lower limit to the age of the universe and to search for Exoplanets. The project MOST consists of a low earth orbiting (LEO) satellite and three ground stations, one of them in Vienna [W. Weiss et al., 2003]. The Vienna ground station system was set up at the Institute for Astronomy of the University of Vienna in cooperation with the Institute of Communications and Radio-Frequency Engineering of the Vienna University of Technology. The downlink budget calculations are done for the worst propagation conditions. Among measurements related to the performance it is finally measured the figure of merit (G/T_s ) of the receiving system based on the sun flux density method