RAIM accuracy limit for the Approach phase is closest to what value?

RAIM accuracy limit for the Approach phase is closest to what value?

• A. 0.3 NM
• B. 1.0 NM
• C. 2.0 NM
• D. 5.0 NM

Answer: (A)

The main idea here is how confident we must be in GNSS position during the Approach phase. RAIM provides an integrity bound, a protection level, that says how large the position error could be while still meeting the required reliability. For an approach, especially near the runway and obstacles, the system must guarantee tight lateral accuracy. The typical RAIM protection/accuracy limit used for the approach phase is about 0.3 nautical miles, which corresponds to roughly 0.56 kilometers. This is the value that matches the strict integrity needs on final approach. The larger numbers would not provide enough positional certainty to ensure obstacle clearance and safe path following on approach.

The main idea here is how confident we must be in GNSS position during the Approach phase. RAIM provides an integrity bound, a protection level, that says how large the position error could be while still meeting the required reliability. For an approach, especially near the runway and obstacles, the system must guarantee tight lateral accuracy. The typical RAIM protection/accuracy limit used for the approach phase is about 0.3 nautical miles, which corresponds to roughly 0.56 kilometers. This is the value that matches the strict integrity needs on final approach. The larger numbers would not provide enough positional certainty to ensure obstacle clearance and safe path following on approach.