In-orbit measurement and analysis of the "Little-LEO" VHF up-link frequencies using a LEO microsatellite

The increasing demand for low cost global data communications, has lead to an increasing requirement for frequency allocations within the "Little LEO" VHF frequency band. Consequently the study of the low Earth orbit (LEO) communications link environment has become increasingly popular, however a lack of satellites operating in the appropriate frequency band severely limits these studies. This paper presents a set of in-orbit measurements of the long term frequency usage or interference, experienced in low Earth polar orbit in the "Little LEO" VHF band using the HealthSAT II microsatellite. Further analysis of these in-orbit measurements provides valuable information for system design on a global scale. It can be seen that long term usage of these frequencies by other services both satellite and terrestrial, can potentially cause severe degradation to power limited applications, trying to coexist in the same band.