RAIM stands for what?

• A. Receiver Autonomous Integrity Monitoring
• B. Remote Aeronautical Information Management
• C. Radar Airspace Integrity Monitoring
• D. Required Aircraft Interference Measure

Answer: (A)

RAIM stands for Receiver Autonomous Integrity Monitoring. The key idea is that the GPS receiver self-checks the integrity of its navigation solution using redundant satellite measurements. By comparing the pseudorange data from multiple satellites, the receiver can detect faults, and if there are enough healthy satellites, it can exclude the faulty one and still provide a trusted position solution. This capability is essential for IFR operations, where you rely on GPS for navigation and changes in integrity status may require switching to alternate navigation methods. If RAIM indicates that integrity is not available, you shouldn’t rely on GPS for critical decisions and should use other approved navigation sources. The other terms aren’t standard meanings for RAIM.