🔍 Key Concepts

• Inmarsat-C operates with small, fixed antennas that do not need to track the satellite mechanically • Difference between polarization (RHC, vertical, horizontal) and radiation pattern (directional vs omni-directional) • Characteristics needed on a ship that may roll and pitch but still must maintain continuous satellite coverage

💭 Think About

• Ask yourself: on a rolling vessel, would a highly directional antenna or an omni-directional antenna be more reliable to stay linked with the satellite? • Think about what RHC (right-hand circular) polarization is used for in satellite communications and why it might be preferred over linear polarization at sea. • Consider which option best matches a compact, fixed, no-moving-parts antenna that can be mounted almost anywhere on a vessel.

✅ Before You Answer

• Verify which options describe directional vs omni-directional patterns and which would be practical on a moving ship. • Check which polarizations (vertical, horizontal, RHC) are most common for maritime satellite services like Inmarsat. • Eliminate any choices that would require precise pointing or stabilization of the antenna as the vessel moves.