Electrical Engineering Department
BS in Electrical Engineering
Cal Poly's satellites design team, PolySat, has three satellites in Low Earth Orbit (LEO) and four more planned to launch within the next two years. Radio communication of past and current orbiting satellites has been an exercise in frustration, prompting significant research into the satellite-side of the radio link by several other Senior Projects and Thesis papers. However, minimal effort has been spent on evaluating why these problems were discovered only once the satellites reached orbit. This paper details the downfalls of relying heavily on link budgets and improper long range test setups, then experimentally determines the sensitivity of PolySat's primary ground station, Marconi. Results are compared to theoretical link budgets to determine incorrect parameters that need to be changed.
The ultimate goal of this testing is to pave the way for the 'New Bus' ground station. This in-development ground station uses satellite hardware to simplify ground operations and increase uplink/downlink performance and robustness. In depth sensitivity testing discovered an extremely high noise temperature of 4365K on Marconi, which will likewise limit performance on the New Bus ground station due to a similar antenna configuration. Downlink requirements will not be met until the ground station's noise floor is decreased.