| Label | Concept definition | Figure(s) | Attribute value type | EQ label | Code |
|---|---|---|---|---|---|
| ICAO_AIRSPACE_CLASS | The class of an ICAO <AIRSPACE>. | ENUMERATION | 483 | ||
| ICE_COVERAGE_FRACTION | A number between 0 and 1 inclusive representing the linearly-scaled fraction of a <WATERBODY_SURFACE> that is covered by floating <ICE>. Zero means no floating <ICE> is present and one means the <WATERBODY_SURFACE> is completely covered. | REAL | PURE_NUMBER | 484 | |
| ICE_COVERED | An indication that a <WATERBODY_SURFACE> is covered with <ICE>. | BOOLEAN | 485 | ||
| ICE_DRAFT_ROOT_MEAN_SQUARE | The root-mean-square <<DEPTH>> of the layer of surface <ICE> within a delineated <WATERBODY_SURFACE_REGION>; ice draft root-mean-square. | REAL | LENGTH | 486 | |
| ICE_KEEL_DENSITY | The areal density of <ICE_KEEL>s within a delineated <WATERBODY_SURFACE_REGION>. | REAL | AREAL_ENTITY_DENSITY | 487 | |
| ICE_LAYER_THICKNESS | The <<THICKNESS>> of a layer of <ICE> on a <WATERBODY_SURFACE>. | REAL | LENGTH | 488 | |
| ICING_TYPE | The type of any deposit or coating of <ICE> on an <OBJECT> caused by the impingement and freezing of liquid (usually supercooled) hydrometeors; icing type. | ENUMERATION | 489 | ||
| IGNITION_FLASH_INTENSITY |
A number between 0 and 1 inclusive representing the linearly-scaled fraction of the transient illumination intensity that is associated with an <OBJECT> and that has been induced by ignition of a combustible <MATERIAL>; ignition flash intensity. EXAMPLE Launch of a <MUNITION>. Zero means no intensity at all and one means maximum intensity. |
REAL | PURE_NUMBER | 490 | |
| ILLUMINANCE | The photometric equivalent of irradiance that is obtained by integrating spectral irradiance weighted by luminous efficiency over the visible spectrum; illuminance. | REAL | RADIANT_ENERGY_FLUENCE | 491 | |
| ILLUMINANCE_DIRECT | The amount of <<ILLUMINANCE>> that is direct (rather than diffuse). | REAL | RADIANT_ENERGY_FLUENCE | 492 | |
| ILLUMINANCE_DIRECT_FROM- _PRINCIPAL_SOURCE |
The <<ILLUMINANCE_DIRECT>> from the principal source of illumination (for example: the <SUN> and/or an illumination flare). | REAL | RADIANT_ENERGY_FLUENCE | 493 | |
| IMO_ADOPTED | An indication that a TSS has been adopted by the IMO [DFDD, Feature Attribute Dictionary, IAS]. | BOOLEAN | 494 | ||
| INCIDENCE_AZIMUTH_GEODETIC | The <<VECTOR_AZIMUTH_GEODETIC>> toward the source of incident light (the <DIRECTION> negative to the Poynting vector); incidence azimuth geodetic. | REAL | PLANE_ANGLE | 495 | |
| INCIDENCE_AZIMUTH_LOCAL | The <<VECTOR_AZIMUTH_LOCAL>> toward the source of incident light (the <DIRECTION> negative to the Poynting vector); incidence azimuth local. | REAL | PLANE_ANGLE | 496 | |
| INCIDENCE_AZIMUTH_MAGNETIC | The <<VECTOR_AZIMUTH_MAGNETIC>> toward the source of incident light (the <DIRECTION> negative to the Poynting vector); incidence azimuth magnetic. | REAL | PLANE_ANGLE | 497 | |
| INCIDENCE_ELEV_ANGLE- _HORIZONTAL |
The <<VECTOR_ELEV_ANGLE_HORIZONTAL>> toward the source of incident light (the <DIRECTION> negative to the Poynting vector); incidence elevation angle horizontal. | REAL | PLANE_ANGLE | 498 | |
| INCIDENCE_ELEV_ANGLE_LOCAL | The <<VECTOR_ELEV_ANGLE_LOCAL>> toward the source of incident light (the <DIRECTION> negative to the Poynting vector); incidence elevation angle local. | REAL | PLANE_ANGLE | 499 | |
| INCIDENCE_ZENITH_ANGLE_LOCAL | The angle at a <LOCATION> on a <SURFACE> between the vectors A and B, where A is the surface normal vector and B is the <DIRECTION> from which the source light is incident on that point (the negative of the Poynting vector); incidence zenith angle local. The positive sense is clockwise when looking in the <DIRECTION> of the cross product AxB. | REAL | PLANE_ANGLE | 500 | |
| INFRARED_HEAT_FLUX | The rate of flow (flux) of heat to a <SYSTEM> due to infrared radiation. | REAL | IRRADIANCE | 501 | |
| INLAND_HYDROLOGIC_PERSISTENCE | The persistence of an inland <HYDROLOGIC_OBJECT>. | ENUMERATION | 502 | ||
| INLAND_WATER_OBSTRUCTION | An indication that an <OBJECT> in <INLAND_WATER> is an obstruction to the movement of <VESSEL>s. | BOOLEAN | 503 | ||
| INSIDE_DIAMETER | The diameter of a cylindrical or spherical <OBJECT> measured using the inside <SURFACE>s. | REAL | LENGTH | 504 | |
| INSTALLATION_BUOY_TYPE | The type of an installation <BUOY>. | ENUMERATION | 505 | ||
| INTEG_BIDIRECTIONAL- _REFLECTANCE_DISTRIBUTION- _FUNCTION |
The ratio, for a particular material <SURFACE>, of the differential reflected <<RADIANCE>> into a unit solid angle about a particular (reflected) <DIRECTION> to the differential incident flux per unit surface <<AREA>> (irradiance) from a particular (incident) <DIRECTION>; integrated bidirectional reflectance distribution function. This quantity, which is also known as integrated directional-directional reflectance, is a function of the incident and reflected zenith and azimuth angles. This quantity is <<WAVELENGTH>>-band integrated, and the particular band is specified separately. | REAL | RECIPROCAL_SOLID_ANGLE | 506 | |
| INTEG_DIRECTIONAL- _HEMISPHERICAL_REFLECTIVITY |
The ratio, for a particular material <SURFACE> and unit solid angle about a particular incident <DIRECTION>, of the reflected <<RADIANCE>> into the hemisphere above that <SURFACE> to the incident <<RADIANCE>>; integrated directional hemispherical reflectivity. This quantity is also defined as the integral over the reflected hemisphere of the BRDF times the cosine of the angle between the surface normal and the reflection <DIRECTION> times the differential reflection solid angle. It is a function of the zenith and azimuth angles of the incident light and is <<WAVELENGTH>>-band integrated, therefore the quantity is unitless and the particular band is specified separately. | REAL | PURE_NUMBER | 507 | |
| INTEG_HEMISPHERICAL- _DIRECTIONAL_REFLECTIVITY |
The ratio, for a particular material <SURFACE> and unit solid angle about a particular reflection <DIRECTION>, of the reflected <<RADIANCE>> into that solid angle to the purely diffuse, total incident <<RADIANCE>> from the hemisphere above that <SURFACE>; integrated hemispherical directional reflectivity. | REAL | PURE_NUMBER | 508 | |
| INTEG_HEMISPHERICAL- _HEMISPHERICAL_REFLECTIVITY |
The ratio, for a particular material <SURFACE> and unit solid angle about a particular reflection <DIRECTION>, of the reflected <<RADIANCE>> into that solid angle to the purely diffuse, total incident <<RADIANCE>> from the hemisphere above that <SURFACE>; integrated hemispherical hemispherical reflectivity. This quantity is also defined as the integral over the incident hemisphere of the BRDF times the cosine of the angle between the surface normal and the incidence <DIRECTION> times the differential incident solid angle. It is a function of the zenith and azimuth angles of the reflected light and is <<WAVELENGTH>>-band integrated, therefore the quantity is unitless and the particular band is specified separately. | REAL | PURE_NUMBER | 509 | |
| INTERCHANGE_TRAVERSABILITY |
The traversability provided at a four-way <ROAD_INTERCHANGE> between the entry segments of adjacent <ROAD>s. Each entry segment necessarily connects to an opposing exiting segment (two pairs are thus formed) and optionally to either of the adjacent left or right entry segments. The first entry segment is that entering the interchange in the <DIRECTION> of the associated <BRIDGE_SPAN>; the remaining three entry segments are ordered in a counter-clockwise <DIRECTION> with the third entry serving as the exit for the first entry, and similarly the fourth for the second. The value is formatted in a Basic Latin string containing exactly four characters with the ith character corresponding to traversability from the ith entry (I = 1, 2, 3 and 4). Each character position in the string contains one of the characters N (no turns), R (right turn), L (left turn) or B (both right and left turn). EXAMPLE "NRBL" means no turns from first entry; right turn from second entry; right and left turn from third entry; and left turn from fourth entry. |
CONSTRAINED_STRING | 510 | ||
| INTEREST_TYPE | The reason an <OBJECT> is of interest; interest type. | ENUMERATION | 511 | ||
| INTERIOR_AIR_EXCHANGE_RATE | The number of complete exchanges of the interior <AIR> in a <STRUCTURE> per unit time; interior air exchange rate. | REAL | RATE | 512 | |
| INTERIOR_LIGHTING_INTENSITY | A number between 0 and 1 inclusive representing the linearly-scaled fractional intensity of the general internal <LIGHTING> of an <OBJECT>; interior lighting intensity. Zero means unlit and one means maximum intensity. | REAL | PURE_NUMBER | 513 | |
| INTERIOR_WALL_CONSTRUCTION- _TYPE |
The type of <MATERIAL> and/or techniques used to construct an <INTERIOR_WALL>; interior wall construction type. | ENUMERATION | 514 | ||
| INTERIOR_WINDOW_COVERING | The type of the internal covering of a <WINDOW>. | ENUMERATION | 1698 | ||
| INTERNAL_FLOW_SPEED | The <<SPEED>> of any internal convective flow within an <OBJECT>. | REAL | SPEED | 515 | |
| INTERNAL_FROUDE_NUMBER_ATM | A modified Froude number used for atmospheric flows over <HILL>s or other obstacles given by the non-dimensional ratio of the fluid speed to the product of Brunt-Väisälä frequency and a characteristic length; internal Froude number atmospheric. | REAL | PURE_NUMBER | 1677 | |
| INTERNAL_TEMPERATURE | The internal <<TEMPERATURE>> of a <MATERIAL> or <OBJECT>. | REAL | THERMO_TEMPERATURE | 516 | |
| INTERNALLY_HEATED | An indication that the <<TEMPERATURE>> of a <MAN_MADE_OBJECT> is being influenced by an internal heat source; internally heated. | BOOLEAN | 1668 | ||
| IONOSPHERIC_SCINT_EAST_DRIFT | The <<SPEED>> of eastward drift of the electromagnetic scintillation density irregularities in an <IONOSPHERE>. | REAL | SPEED | 517 | |
| IONOSPHERIC_SCINT_MAXIMUM_SIZE | The upper limit on the size of the electromagnetic scintillation density irregularities in an <IONOSPHERE>; ionospheric scintillation maximum size. | REAL | LENGTH | 518 | |
| IONOSPHERIC_SCINT_NORTH_DRIFT | The <<SPEED>> of northward drift of the electromagnetic scintillation density irregularities in an <IONOSPHERE>. | REAL | SPEED | 519 | |
| IONOSPHERIC_SCINT_PHASE- _ALTITUDE |
The <<ALTITUDE_MSL>> of the equivalent electromagnetic scintillation phase screen in an <IONOSPHERE>. | REAL | LENGTH | 520 | |
| IONOSPHERIC_SCINT_STRUCTURE- _ANGLE |
The angle between the electromagnetic scintillation irregularities and <LINE>s of the local <MAGNETIC_FIELD>; ionospheric scintillation structure angle. If zero, all ionospheric plasma density irregularities are aligned along the local <MAGNETIC_FIELD>. | REAL | PLANE_ANGLE | 521 | |
| IONOSPHERIC_SCINT_UP_DRIFT | The <<SPEED>> of upward drift of the electromagnetic scintillation density irregularities in an <IONOSPHERE>. | REAL | SPEED | 522 | |
| IRRIGATION_METHOD | The method used to supply crops with <WATER>; irrigation method. | ENUMERATION | 523 | ||
| ISLAMIC_DENOMINATIONAL_FAMILY | The designation of a <NON_EMPTY_SET> of closely related Islamic religious denominations, often ones which were at one time part of a single movement but are now separate religious denominations; Islamic denominational family. | ENUMERATION | 524 | ||
| ISOBARIC_SURFACE_LEVEL | The <<ALTITUDE_MSL>> of a standard isobaric <SURFACE> in units proportional to the potential energy of unit <<MASS>> (geopotential) at that <SURFACE>. | REAL | GEOPOTENTIAL_ENERGY_LENGTH | 525 | |
| ISOLATED | An indication that a material <OBJECT> is in the open by itself, isolated from other <OBJECT>s of a similar type, and thus is visually distinct from surrounding <OBJECT>s when viewed from a distance. | BOOLEAN | 526 | ||
| ISOLATED_COMMUNICATION_LINE | An indication that a communication line is in the open (isolated), as opposed to being in the midst of other <OBJECT>s (not isolated). | BOOLEAN | 527 |
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