What is one of the required components of a ground-based CAT II navigation system?

A ground-based Category II (CAT II) navigation system is designed to assist aircraft in landing during low visibility conditions. One key component of this system is the Outer Marker, which plays a crucial role in providing positional information.

The Outer Marker marks a specific point along the approach path, indicating that an aircraft is at a defined distance from the runway threshold. When an aircraft passes over the Outer Marker, it helps the flight crew determine their position and make informed decisions regarding the landing process, particularly important in minimizing the risk during low visibility.

The other components mentioned may support flight operations in broader contexts but are not specifically required for a CAT II navigation system. For instance, a Ground Control Station is primarily associated with unmanned aerial systems; a Flight Recording Device is mainly for tracking flights and analyzing performance post-flight; and Weather Radar aids in weather monitoring rather than providing the precise position needed for the CAT II approach. Therefore, the inclusion of the Outer Marker as part of a CAT II system is fundamental for enhancing the safety and accuracy of landings under challenging visibility conditions.