Local Coordinate Systems

Name

Range

Description

Optional?

<coordSysName>

any string

The name of the coordinate system being de­fined may be used to identify the coordinate system of a reader or writer, or as an argu­ment to @Reproject or _COORDINATE_SYSTEM.

No

<unit name>

See Coordinate Units Supported.

The name of the units used to measure coor­dinates in the coordinate system.

No

<projType>

See Projection Types.

The type of map projection used for this def­inition. This name must come from the Projection Types  table and it determines which other pa­rameters may be specified. The parameters used by each projection type linked to this table.

No

<parameter>

Depends on the pro­jection system – see Projection Types.

Each projection system uses a set of parame­ters, which are listed for each supported project.

No

<datumName>

See Datums.

The datum to be used for the projection. Ei­ther a datum or an ellipsoid must be specified for each coordinate system.

Yes

<ellipName>

See Ellipsoids.

The ellipsoid to be used for the projection. Ei­ther a datum or an ellipsoid must be specified for each coordinate system.

Yes

<quadrant>

-4..4

The quadrant of the Cartesian coordinates produced by the coordinate system. See Quadrant.

Yes

<descriptive name>

any string

A descriptive name of the definition.

Yes

<source>

any string

Person or agency supplying the definition.

Yes

<zero_x>

any non-negative number

Used to specify the minimum X value which is to be considered non-zero. X coordinate values whose absolute value is less than the value specified here will be converted to hard zeros.  This is used to suppress coordinate output such as 4.3472E-07 which can be of value in certain applications.  A value of 0.0 is assumed if no specification is made.

Yes

<zero_y>

any non-negative number

Used to specify the minimum Y value which is to be considered non-zero. Y coordinate values whose absolute value is less than the value specified here will be converted to hard zeros.  This is used to suppress coordinate output such as 4.3472E-07 which can be of value in certain applications. A value of 0.0 is assumed if no specification is made.

Yes