CRS Linking File

The boundcrs.dat file associates (links) Coordinate Reference Systems to datum transformations.

Datums are defined in datum.dat or epsg.db. However, two datums are exclusive to this file:

• RDNAP For use with compound CRS EPSG:7415 "Amersfoort / RD New + NAP height" Uses the RDNAPTRANS™ method and the following grid shift files: nlgeo04.grd, x2c.grd, y2c.grd.

• NTFRFG93_4275 and NTFRFG93_4807: For use with CRS that have a base geodetic CRS of EPSG:4275 and EPSG:480 respectively. Use the NTv2 method, requires the grid shift file ntf_r93.gsb.

The file format is shown below:

CRS_ID,EPSG-CRS-ID,DatumTxID

where:

• CRS_ID is a unique identifier for the link (mapdef lookup key or EPSG link)

• EPSG-CRS-ID is the EPSG identifier for the coordinate reference system.

• DatumTxID is the identifier for a datum transformation. N/A can be entered for no transformation.

Sample

Entries from boundcrs.dat: