항공정보

Table A1-9. Data types    [Excel Down]
Type (1)	Description (2)	Data elements (3)
Point	A pair of coordinates (latitude and longitude) referenced to the mathematical reference ellipsoid which define the position of the point on the surface of the Earth.	Latitude
Point		Longitude
Point		Horizontal reference system
Point		Units of measurement
Point		Horizontal accuracy achieved
Line	Sequence of Points defining a linear object	Sequence of Points
Polygon	Sequence of Points forming the boundary of the polygon. The first and last Point are identical.	Closed sequence of Points
Height	The vertical distance of a level, point or an object considered as a point, measured from a specific datum.	Numerical value
Height		Vertical reference system
Height		Units of measurement
Height		Vertical accuracy achieved
Altitude	The vertical distance of a level, a point or an object considered as a point, measured from mean sea level.	Numerical value
Altitude		Vertical reference system
Altitude		Units of measurement
Altitude		Vertical accuracy achieved
Elevation	The vertical distance of a point or a level, on or affixed to the surface of the earth, measured from mean sea level.	Numerical value
Elevation		Vertical reference system
Elevation		Units of measurement
Elevation		Vertical accuracy
Distance	A linear value	Numerical value
Distance		Units of measurement
Distance		Accuracy achieved
Angle / Bearing	An angular value	Numerical value
Angle / Bearing		Units of measurement
Angle / Bearing		Accuracy achieved
Value	Any measured, declared or derived value not listed above.	Numerical Value
Value		Units of Measurement
Value		Accuracy achieved
Date	A calendar date referencing a particular day or month	Text
Schedule	A repetitive time period, composed of one or more intervals or special dates (e.g. holidays) occurring cyclically	Text
Code list	A set of predefined Text strings or values	Text
Text	Free text	String of characters without constraints