CoordSys

Description

Describes a coordinate system for georeferencing.

A 3D geographic coordinate system has the following axes:

  1. X: Geodetic longitude
    Angle from the prime meridian plane to the meridian plane passing through the given point, eastwards treated as positive.

  2. Y: Geodetic latitude
    Angle from the equatorial plane to the perpendicular to the ellipsoid through a given point, northwards treated as positive.

  3. Z: Ellipsoidal height
    Distance of a point from the ellipsoid measured along the perpendicular from the ellipsoid to this point. Positive if upwards or outside of the ellipsoid.

A projected coordinate system has the following X and Y axes:

  1. X: Easting
    East pointing axis used in 2D projected coordinate systems.

  2. Y: Northing
    North pointing axis used in 2D projected coordinate systems.

Vertical coordinate systems have a different Z axis, usually gravity-related height or depth.

Fields / Optional

id

Type

Georef.Id

Default

null

The unique registry ID of well-known objects.


name

Type

string

Default

null

The human-readable name of this object.


geographic

Type

Datum

Default

null

The geodetic datum this coordinate system is based upon.


projection

Type

CoordOpBase

Default

null

The map projection that translates between geographic coordinates (latitude, longitude) and map coordinates (easting, northing).


vertical

Type

Georef.Vertical

Default

null

The vertical datum this coordinate system is based upon (null defaults to ellipsoid height).


geographicUnit

Type

Unit

Default

null

The unit of measure used for geographic coordinates (null defaults to degrees).


projectionUnit

Type

Unit

Default

null

The unit of measure used for projected coordinates (null defaults to metres).


localUnit

Type

Unit

Default

null

The unit of measure used for local coordinates (null defaults to metres).


verticalUnit

Type

Unit

Default

null

The unit of measure used for vertical coordinates (null defaults to metres).


flags

Type

CoordSys.Flags[]

Default

[None]

The coordinate system flags.