Sun outage calculator for satellite communications

Finland resides in high latitudes, and as a consequence requires larger receiver antennas due to the signal from the geosynchronous satellite having a longer atmospheric propagation path, as well as Finland often being at the edge of the geosynchronous communication satellite footprint. This however narrows the beamwidth of the antenna and so in turn strengthens the effect of sun outages. This work describes what a sun outage is, how its magnitude is dependent on sun activity and satellite-receiver geometry, and how a new, comprehensive calculator was developed to be able to calculate accurately when such a phenomenon occurs for any user-defined satellites and receiver locations, and how much the received signal degrades. Thus, appropriate countermeasures can be taken to keep the communication link working. The emphasis is on geosynchronous satellites, which are mostly used for communication and experience sun outages, by definition of their orbit, twice per year. The results of the calculator were compared to field measurements, and were relatively similar. There are plenty of computational tools available on the internet with which anyone can predict, with varying limitations, when and with what strength a sun outage occurs at a particular ground station. Several of the publicly available calculators make different assumptions, and so cannot predict the true duration of the outage, or miss them completely. This is why the calculator program developed has more possibilities for inputs, such as the solar flux, as now the sun outage duration and noise temperature rise are related to the sun activity.