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For the end-user, the appearance of the RPN is that of a flat-file database structure. A single file contains numerous records which hold fields on 1, 2 or 3D data grids and self-describing information about the fields (header).

A thorough set of FST-related routines are contained in the RPN Library (armnlib). These routines provide easy access to the file contents. They can be called from FORTRAN or C routines.

A complete description of the FST file format and the utilities which can be used to manipulate and view their contents is available online at www.cmc.ec.gc.ca/rpn/utilities.

Sometimes the files are archived in an cmc-archive file (*.ca). If this is the case they need to be unarchived first.

The maximum size of RPN file is a little more than 8 GB!!! If you are trying to write a file larger than the maximum size the file will not get closed. Meaning no application will be able to open it and it can be considered as "corrupted". The usual error message one get when trying to open such a file is "file (unit=...) currently used by another application in write mode".

Looking at RPN files

vl3, vl4, vl5 -> list variable with description

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