🔍 Key Concepts

• Line-of-sight satellite communication between ship earth station (SES) antenna and the satellite • Effects of physical obstructions and elevation angle on satellite links • How weather and distance from the satellite’s coverage area can affect signal quality

💭 Think About

• Which of these options would completely or almost completely stop the SES antenna from "seeing" the satellite, instead of only weakening the signal? • Think about how Inmarsat-FBB is designed for ocean-going ships: which type of common environmental condition would the system be engineered to tolerate reasonably well? • Which condition describes a situation where the satellite is no longer in a usable position or coverage area for that ship?

✅ Before You Answer

• For each option, ask: does this cause loss of line of sight between antenna and satellite, or just signal attenuation (weakening)? • Recall that Inmarsat systems are designed with some rain fade margin—how does that relate to "normal" gales and storms? • Consider the meaning of satellite elevation and coverage radius (footprint) and how moving outside that footprint or below the horizon affects communications.