Aviation Glossary

At Dauntless, our editorial staff maintains the web's largest unified glossary of aviation terms. This glossary is built from a combination of official, quasi-official, and proprietary sources (including original material that we develop oursselves). Uniquely, we often provide multiple definitions of a given term so that you can find that which best applies to you. In order to maximize your learning efficiency, this glossary (and similar ones for our international users) is incresingly fully integrated into our aviation learning apps, including our FAA written test prep and FAA practical test prep software and apps. If you like this glossary, you'll love them with their polished learning environments and world's best and clearest content (please do give them a try.).

RAIM

The self-monitoring function performed by a TSO-129 certified GPS receivers to ensure that adequate GPS signals are being received at all times. The GPS will alert the pilot whenever the integrity monitoring determines that the GPS signals do not meet the criteria for safe navigation use.

source: FAA Advanced Avionics Handbook (FAA-H-8083-6)

A technique whereby a civil GNSS receiver/processor determines the integrity of the GNSS navigation signals without reference to sensors or non-DoD integrity systems other than the receiver itself. This determination is achieved by a consistency check among redundant pseudorange measurements.

source: FAA Pilot/Controller Glossary

Receiver Autonomous Integrity Monitoring (RAIM): A system used to verify the usability of the received GPS signals and warns the pilot of any malfunction in the navigation system. This system is required for IFR-certified GPS units.

source: FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25A)

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Disclaimer: While this glossary in most cases is likely to be highly accurate and useful, sometimes, for any number of editorial, transcription, technical, and other reasons, it might not be. Additionally, as somtimes you may have found yourself brought to this page through an automated term matching system, you may find definitions here that do not match the cotext or application in which you saw the original term. Please use your good judgement when using this resource.