What is the primary use of the E-scan or RHI?

The primary use of the E-scan or RHI (Range Height Indicator) is indeed to assist in directing aircraft during ground and controlled approaches. This technology plays a crucial role in ensuring safe landings by providing accurate altitude and range information to pilots. It generates a profile of the atmosphere, offering real-time data on weather patterns and obstacles that may affect aircraft navigation, particularly around airports. By utilizing this information, air traffic controllers and pilots can make informed decisions to maintain safe flight operations and ensure efficient landing procedures.

While other options may relate to different radar or scanning technologies, they do not align with the specific capabilities and functions of the E-scan or RHI in supporting aircraft navigation and approach.