Support Files : GDAL Datum Mapping
 

GDAL Datum Mapping

The datum mapping file provides definitions for datums that are unknown to CARIS. Each definition can be provided as either an EPSG datum ID or as a Well Known Text (WKT) definition. All datum definitions must be transformable to the WGS 1984 datum.

Datum mapping support files are located in the gdalsupport folder (C:\Program Files\CARIS\<application>\<version>\system\gdalsupport).

EPSG datum ID

The following EPSG transformation methods are supported:

• EPSG::9603 - Geocentric translations (geog2D domain) For example,

<!-- EPSG::9603 - Geocentric translations (geog2D domain) -->

<cdl:Datum>

<cdl:Name>Guam_1963</cdl:Name>

<cdl:EPSG xlink:href="urn:ogc:def:datum:EPSG::6675"/>

</cdl:Datum>

• EPSG::9606 - Position Vector transformation (geog2D domain). For example,

<!-- EPSG::9606 - Position Vector transformation (geog2D domain) -->

<cdl:Datum>

<cdl:Name>OSNI_1952</cdl:Name>

<cdl:EPSG xlink:href="urn:ogc:def:datum:EPSG::6188"/>

</cdl:Datum>

• EPSG::9607 - Coordinate Frame Rotation (geog2D domain). For example,

<!-- EPSG::9607 - Coordinate Frame Rotation (geog2D domain) -->

<cdl:Datum>

<cdl:Name>Amersfoort</cdl:Name>

<cdl:EPSG xlink:href="urn:ogc:def:datum:EPSG::6289"/>

</cdl:Datum>

WKT definition

Several WKT definitions are supported.

When providing a WKT definition using the EPSG::9606 method, the 'TOWGS84' element must be specified.

The following is an example definition from datummapping.xml, in
C:\Program Files\CARIS\<application>\<version>\system.

<!-- GCS_WGS_84 -->

<cdl:Datum>

<cdl:Name>World_Geodetic_System_1984</cdl:Name>

<cdl:EPSG xlink:href="urn:ogc:def:datum:EPSG::6326"/>

<cdl:WellKnownText>DATUM["World Geodetic System 1984",

SPHEROID["WGS 84",6378137,298.2572201434276],

TOWGS84[0,0,0,0,0,0,0]]</cdl:WellKnownText>

</cdl:Datum>