EntityQ1104030· pop 22· linked from 447 articlesradar altimeterSign in to savedevice which measures altitude above the terrain presently beneath an aircraft or spacecraftConnectionsradio navigationEntitycommunications satelliteEntityradio broadcastingEntityautopilotEntityradiolocationEntitycontinuous-wave radarEntityinstrument landing system glide pathEntityheight above ground levelEntityWorld War IIConceptVenusEntityradioEntityInternational Standard Book NumberEntityOxfordEntityBBCConceptNewfoundland and LabradorEntityspeed of light in vacuumEntitycompassEntityGuglielmo MarconiEntityCornwallEntityGlobal Positioning SystemEntityCategoriesAir traffic controlMeasuring instrumentsNavigationNavigational aidsNavigational flight instrumentsRadio navigation