Which term refers to the measure of altitude ensuring NAVAID reception during an emergency approach?

The term that refers to the measure of altitude ensuring NAVAID reception during an emergency approach is known as "Minimum Safe Altitude" (MSA). This altitude is particularly significant in navigational procedures because it provides a margin of safety for aircraft as they navigate toward a NAVAID, especially in emergency situations or when the aircraft may be operating in less than optimal conditions.

MSA is designed to ensure that an aircraft remains above the highest terrain and obstacles within a specified distance of the NAVAID, allowing for safer navigation and approach. It is established based on topographical data and considers obstructions in the surrounding area, ensuring that pilots can maintain a safe altitude while receiving signals from navigational aids.

In contrast, other terms such as Decision Height, which is the altitude at which a pilot must decide whether to continue an approach or execute a go-around, and Minimum Enroute Altitude, which ensures acceptable navigational signal reception along a route, do not specifically focus on emergency approaches as MSA does. Safe Altitude generally refers to the altitude that guarantees obstacle clearance but does not tie directly to NAVAID reception in emergency scenarios.