Sun Outage Calculator for Geostationary Orbit Satellites
Jouko Vankka, Antti Kestilä
Corresponding author (email) : jouko.vankka@mil.fi
Abstract
Sun outages in satellite communication occur when the sun, a powerful broadband microwave noise source, passes directly behind the satellite (when viewed from Earth), causing the receiver with the beam directed towards the satellite to pick up the satellite signal and the noise from the sun. A new type of calculator was developed to accurately determine the occurrence of such phenomena for any chosen geostationary satellite and receiver location combination. The calculator outputs the degradation experienced by the satellite signal, enabling the receiver to take suitable countermeasures. The results from the calculator program were compared with measurement results and agreed to a good degree. Several different open-source calculation tools exist for sun outages. However, these tools are either built from incorrect assumptions or lack of a useful function, leading to inaccurate predictions for strength and beginning/ending time of the outages. The program described in this work has more inputs, such as the solar fl ux, with which the sun’s activity can be considered when calculating outage duration and receiver noise temperature. Regression analysis was used to develop a linear model to estimate daily solar fl ux at a frequency of interest from the day’s solar fl ux 2800 MHz observations (F10.7).
Keywords : Solar interference; sun outage; satellite communications