Table 6.4 -- EDCS Attributes whose label begins with A
| Label | Definition | Attribute value type | EQ label | Related concepts | Code |
| ABSOLUTE_HORIZ_ACCURACY | The difference between the recorded horizontal coordinates of an object and its true position expressed as a circular error at 90% probability. | REAL | LENGTH | EA RELATIVE_HORIZ_ACCURACY | 1 |
| ACCUMULATED_PRECIP | The depth of the precipitation (water equivalent) that accumulated during a measurement time interval. | REAL | LENGTH | 2 | |
| ACCUMULATED_PRECIP_24HR | The depth of the precipitation (water equivalent) that accumulated over a twenty-four hour period. | REAL | LENGTH | 3 | |
| ACCURACY | The accuracy of a geographic position. | ENUMERATION | 4 | ||
| ACNOISE_MIZ_MULTIPLIER | The noise level multiplicative correction factor associated with a marginal ice zone. | REAL | PURE_NUMBER | EA MARGINAL_ICE_ZONE_COVERAGE | 5 |
| ACNOISE_SPECCRV_CORRECTION | The acoustic noise level correction obtained from a spectral class curve to be applied to some base noise level. | REAL | FIELD_OR_POWER_LEVEL | EA SNOISE_SPECCLS_CURVE_IDENT | 6 |
| ACOUSTIC_BOUNDARY_LOSS | The quantity of acoustic energy that is lost due to interaction of the acoustic signal waveform with either the water surface or the bottom, at a specific angle. | REAL | FIELD_OR_POWER_LEVEL | 7 | |
| ACOUSTIC_FREQUENCY_CODED | The acoustic frequency. | ENUMERATION | 8 | ||
| ACOUSTIC_HALFCHANNEL_OBS | The fraction of observations indicating the presence of a half-channel. | REAL | PURE_NUMBER | 9 | |
| ACOUSTIC_POWER_LEVEL_BAND | The band power level of acoustic energy measured 1 metre from the source acoustic centre; this quantity may be qualified by the frequency band. | REAL | PRESSURE_POWER_LEVEL | 10 | |
| ACOUSTIC_PWRLVLSPEC | The ratio of sound wave intensity in a 1 hertz band, to a reference intensity measured 1 metre from the source. | REAL | PRESSURE_POWER_LEVEL | 11 | |
| ACOUSTIC_PWRLVLSPEC_CRRCT | The omni directional ambient noise spectrum level correction at a specified frequency referenced to a 50 hertz reference level. | REAL | FIELD_OR_POWER_LEVEL | 12 | |
| ACOUSTIC_REFLECTOR | Indicates that the object reflects acoustic energy. | LOGICAL | 13 | ||
| ACOUSTIC_SCATSTRN | The column (integrated) acoustic scattering strength (ratio of returned to incident energy); this quantity may be qualified with an acoustic frequency. | REAL | AREIC_POWER_LEVEL | 14 | |
| ACTIVE_ACOUSTIC | Indicates that the object generates intentional emissions of acoustic energy used for the purposes of detection, localization, and/or identification. | LOGICAL | 15 | ||
| AERONAUTICAL_LIGHT_FUNCTION | The type of lighting provided or type of lighting system used. | ENUMERATION | 16 | ||
| AEROSOL_BASE_ALTITUDE | The altitude, relative to MSL, of the lower surface of an aerosol. | REAL | LENGTH | 17 | |
| AEROSOL_PARTICLE_CONC | The particle density of an aerosol in the atmosphere. | REAL | VOLUMETRIC_ENTITY_DENSITY | 18 | |
| AEROSOL_TOP_ALTITUDE | The altitude, relative to MSL, of the upper surface of an aerosol. | REAL | LENGTH | 19 | |
| AEROSOL_TYPE | The type of particle in an aerosol. | ENUMERATION | 20 | ||
| AFTERBURNER_INDUCED_FLAME | The fraction of maximum production rate of visible flame induced by use of aircraft afterburner. The following interpretations may be applied: 1/4: Small, 2/4: Medium, 3/4: Large, 4/4: Maximum. | REAL | PURE_NUMBER | 21 | |
| AIR_ROUTE_SEGMENT_LENGTH | The length of an air route segment. | REAL | LENGTH | 22 | |
| AIR_ROUTE_SEGMENT_WIDTH | The width of an air route segment. | REAL | LENGTH | 23 | |
| AIR_TEMPERATURE | The air temperature at a location. | REAL | THERMO_TEMPERATURE | 24 | |
| AIR_TEMPERATURE_ERROR | The potential error in an air temperature measurement. | REAL | THERMO_TEMPERATURE | 25 | |
| AIRCRAFT_ICING_INTENSITY | The estimated intensity of ice formation that may be expected by an aircraft. | ENUMERATION | 26 | ||
| AIRCRAFT_ICING_LVL_BASE_ALT | The estimated altitude, relative to MSL, of the lower surface of a layer in the atmosphere where an aircraft can expect icing. | REAL | LENGTH | 27 | |
| AIRCRAFT_ICING_LVL_TOP_ALT | The estimated altitude, relative to MSL, of the upper surface of a layer in the atmosphere where an aircraft can expect icing. | REAL | LENGTH | 28 | |
| AIRCRAFT_ICING_TYPE | The type of ice that is expected to accumulate on the surface of an aircraft. | ENUMERATION | 29 | ||
| AIRCRAFT_LANDING_GEAR_POS | The position of the aircraft landing gear in terms of fractional deployment from a fully retracted state. | REAL | PURE_NUMBER | 30 | |
| AIRCRAFT_LOAD_RESTRICTIONS | The description of any load restrictions that apply to aircraft using a facility. | STRING | 31 | ||
| AIRFIELD_ELEVATION | The highest point of an airport's usable runways measured from MSL. | REAL | LENGTH | 32 | |
| AIRFIELD_TYPE | The type of an airfield. | ENUMERATION | 33 | ||
| AIRPORT_EMERGENCY_LGTINT | The fraction of maximum intensity of airport emergency lighting. | REAL | PURE_NUMBER | 34 | |
| AIRPORT_GATE_LGTINT | The fraction of maximum intensity of airport facility gate lighting (external). | REAL | PURE_NUMBER | 35 | |
| AIRPORT_IDENTIFICATION | The unique set of numbers preceded by the appropriate country code that enables an individual airport to be uniquely identified within the database. | STRING | 36 | ||
| AIRSPACE_ALTITUDE_LIMITS | The description of the altitude limits of special use airspaces. | STRING | 37 | ||
| AIRSPACE_IDENTIFIER | The textual identifier of an airspace; used for linking to an external database or reference. | KEY | 38 | ||
| AIRSPACE_OPERATING_RSTRCTS | The status of an airspace and any restrictions that are applicable. | STRING | 39 | ||
| AIRSPACE_ROUTE_TYPE | The type of a specified route designed for channelling the flow of traffic as necessary for the provision of air traffic services. | ENUMERATION | 40 | ||
| AIRSPACE_USE_BOUNDARY | The type of designated airspace within which some or all aircraft may be subject to air traffic control. | ENUMERATION | 41 | ||
| AIRSPACE_USE_LIMITATION | The type of airspace wherein activities must be confined because of their nature and/or wherein limitations may be imposed upon aircraft operations. | ENUMERATION | 42 | ||
| ALL_OBJECT_COUNT | The number of objects of all types within the delineated object's extent. | COUNT | 43 | ||
| ALONGSHORE_CURRENT_SPEED | The speed of surf zone (breaking waves) ocean current moving generally parallel to and adjacent to the shoreline. | REAL | VELOCITY | 44 | |
| AMBIENT_LIGHT_INTENSITY | The fraction of maximum ambient light intensity from an object. | REAL | PURE_NUMBER | EA DIFFUSE_LIGHT_INTENSITY, EA SPECULAR_LIGHT_INTENSITY | 45 |
| AMBIENT_SRF_REFLECTIVITY | The ambient component of the surface reflectivity. Ambient reflectivity may be qualified by other attributes, e.g., the electromagnetic band for which the value applies | REAL | PURE_NUMBER | EA EM_BAND, EA DIFFUSE_SRF_REFLECTIVITY, EA SPECULAR_SRF_REFLECTIVITY, EA SURFACE_REFLECTIVITY | 46 |
| ANGULAR_SECTOR_WIDTH | The width of an angular sector for which the measurement applies. | REAL | PLANE_ANGLE | 47 | |
| ANTENNA_COUNT | The number of distinct antennae on a structure, e.g., a building or tower. | COUNT | 48 | ||
| ANTI_COLLISION_LGTINT | The fraction of maximum intensity of external lighting used to prevent collision with/between vehicles; also known as brake lights. | REAL | PURE_NUMBER | 49 | |
| AQUEDUCT_TYPE | The type of an aqueduct. | ENUMERATION | 50 | ||
| AREA | The absolute area within the delineated region of an object. | REAL | AREA | 51 | |
| ARRESTING_GEAR_TYPE | Type of device used to stop an uncontrolled aircraft at the end of a runway. | ENUMERATION | 52 | ||
| ASPECT_ANGLE | The angle measured from the major axis of an object clockwise to the direction of viewing. Zero represents either the direction of motion, or other unique orientation along the primary axis, heading directly towards the observer. | REAL | PLANE_ANGLE | 53 | |
| ASSET_TYPE | The type of asset, e.g., vehicle, equipment or personnel. | ENUMERATION | 54 | ||
| ASSOCIATED_TEXT | Narrative or other description. | STRING | 55 | ||
| ASW_CENTROID_PRESENT | Indicates that the centroid of an ASW operating region exists within the spatial extent of the associated object. | LOGICAL | 56 | ||
| ATM_BOUNDARY_LAYER_ALTITUDE | The altitude of the planetary boundary layer, that layer of the atmosphere bounded on the bottom by the planetary surface and above by the cessation of turbulent interactions with the planetary surface. | REAL | LENGTH | 57 | |
| ATM_LIQUID_WATER_CONTENT | The liquid water content of the atmosphere at a location. | REAL | VOLUMIC_MASS | 58 | |
| ATM_PRESSURE | The atmospheric pressure at a point. | REAL | PRESSURE | 59 | |
| ATM_PRESSURE_CHANGE_24HR | The quantity of change in atmospheric pressure measured at the beginning and end of a twenty-four hour period. | REAL | PRESSURE | 60 | |
| ATM_PRESSURE_CHANGE_3HR | The absolute value of the quantity of change in atmospheric pressure measured at the beginning and end of a three-hour period. | REAL | PRESSURE | 61 | |
| ATM_PRESSURE_CHANGE_QUALITY | The quality status of an atmospheric pressure change tendency. | ENUMERATION | EA ATM_PRESSURE_CHANGE_TND | 62 | |
| ATM_PRESSURE_CHANGE_RATE | The rate of atmospheric pressure change over a specified time interval. | REAL | PRESSURE_CHANGE_RATE | 63 | |
| ATM_PRESSURE_CHANGE_TND | The qualitative atmospheric pressure change (tendency) that occurred over a three-hour period. | ENUMERATION | 64 | ||
| ATM_PRESSURE_MEAN_CLIM | The mean rate of historical atmospheric pressure. | REAL | PRESSURE | 65 | |
| ATM_PRESSURE_MEAN_CLIM_STDV | The quantity of the standard deviation of historical atmospheric pressures. | REAL | PRESSURE | 66 | |
| ATM_PRESSURE_QUALITY | The quality status of an atmospheric pressure measurement. | ENUMERATION | EA ATM_PRESSURE, EA ATM_PRESSURE_RDCD, EA TERRAIN_SRF_AIR_PRESSURE | 67 | |
| ATM_PRESSURE_RDCD | The pressure reduced to mean sea level using standard procedures. | REAL | PRESSURE | 68 | |
| ATM_PRESSURE_RDCD_CLIM_STDV | The historical standard deviation of the air pressure reduced to mean sea level using standard procedures. | REAL | PRESSURE | 69 | |
| ATS_ROUTE_LEVEL | The ATS Route Structure of which this route is a component. | ENUMERATION | 70 | ||
| ATS_USE_TYPE | The particular use of the designated ATS airspace. | ENUMERATION | 71 | ||
| AVAILABLE_FACILITIES_TYPE | The type of facilities available at or in the near vicinity. | ENUMERATION | 72 | ||
| AVERAGE_WATER_DEPTH | The average water depth. | REAL | LENGTH | 73 | |
| AVERAGE_WATER_SPEED | The average water speed, estimated within delineation of an object, exclusive of high water due to runoff or low water due to drought. | REAL | VELOCITY | 74 | |
| AVERAGE_WATER_SPEED_RANGE | A range indicating the water speed, estimated within delineation of an object (e.g., aqueduct, stream, river outflow region, or drainage canal), exclusive of high water due to runoff or low water due to drought. | ENUMERATION | 75 | ||
| AVERAGING_PERIOD | The period of time over which a measurement has been averaged. | ENUMERATION | 76 |