Battling the Sun in Geostationary Optical Feeder Link Scenarios

The operational requirements for Optical Feeder ground-to-satellite links demand continuous 24-hour functionality of Optical Ground Stations (OGS). This is particularly crucial for Geostationary Equatorial Orbit (GEO) feeder link applications, where high availability is essential. Comprehensive research has been conducted on meteorological conditions like clouds and turbulence, showing that OGS networks can achieve an aggregate availability of 99.7% (at least one OGS is not covered by cloud) through the application of site diversity techniques. However, the potential impact of solar interference on the performance of OGS networks has not been thoroughly explored. Solar blinding, or solar outage, which is influenced by the solar exclusion angle in OGS design (typically ranging from 5 to 10 degrees for telescopes with a diameter of 0.8 to 1 meter), can cause simultaneous outages across entire continental OGS networks, significantly diminishing their annual availability. This work emphasizes the critical need to account for solar blinding effects in the design and operation of optical GEO feeder link networks and evaluates strategies to mitigate them.