MIT ICAT Altimetry Standard Atmosphere Referenced 日29.92 inches of Hg 口3014mb Pressure Altitude O Altitude of Pressure in Std Atmosphere a Used above reference Flight Level (FL180 in US) Density Altitude a Altitude of density in Std Atmosphere Used for performance(TO) Barometric altitude a Estimated altitude corrected for surface pressure D MSL Altitude above Mean Sea Level (QNH) Q AGL Altitude above Ground Level(QFE) Radar Altitude(Cat I and Il Approaches u 5 cm radar- normally only below 3000ft (Terrain Noise Cabin Altitude(Pressurization)MIT ICAT Altimetry y Standard Atmosphere Referenced † 29.92 inches of Hg † 3014 mb y Pressure Altitude † Altitude of Pressure in Std Atmosphere † Used above reference Flight Level (FL180 in US) y Density Altitude † Altitude of density in Std Atmosphere † Used for performance (TO) y Barometric Altitude † Estimated altitude corrected for surface pressure † MSL Altitude above Mean Sea Level (QNH) † AGL Altitude above Ground Level (QFE) y Radar Altitude (Cat II and III Approaches) † 5 cm radar - normally only below 3000ft (Terrain Noise) y Cabin Altitude (Pressurization)