Geomatics Canada has defined conventions for storing NTDB data in four different formats:
- CCOGIF
- ASCII Ungenerate, also known as ArcInfo Generate or ARCGEN
- MID/MIF
- DXF
We refer to each of these as a profile.
The published profiles define conventions for attribute naming, file naming, file composition—for example, organized by NTDB theme versus entity name—and rules for defining the specific attributes’ values. The FME has facilities for generating mapping files that translate CCOGIF into any FME-supported format, closely adhering to one of these three profiles:
- ARCGEN
- MID/MIF
- DXF
These profiles are addressed in greater detail following this discussion on profile-specific mapping files.
Aside from choice of profile, the generated mapping file depends on the following three parameters:
- Choice of Language (English or French): NTDB data encoded into CCOGIF contains both French and English group names and attribute names. A mapping file is configured to choose which language is used on the output file to name output feature types and attribute names.
- Choice of NTDB Revision (2 or 3): NTDB data in CCOGIF follows either the revision 2 or 3 standard. Since this information is not made available to the mapping file generation process, the user must specify it at the time of mapping file generation. A mapping file generated to process mapsheets from one revision cannot be used to process mapsheets from another revision.
- Choice of Scale (50k or 250k): NTDB data can contain information for a 50k or a 250k mapsheet. The user must select which scale of data a mapping file is to work with at the time of mapping file generation. A mapping file generated to process one scale of data may not be used to process a mapsheet from another scale because the set of groups and attributes differ slightly.
These parameters are supplied to FME mapping file generation process using the macros NTDB_Language, NTDB_Version, and NTDB_Scale. When generating a mapping file from the command line, the parameters would be specified something similar to the following command. As no CCOGIF input file is required for a profile-specific mapping file, the word unused is given.
fme generate ntdbcg shape unused mymapping.fme --NTDB_Language French --NTDB_Version 3 --NTDB_Scale 50k
Once a profile-specific mapping file has been generated, it may be stored (for example, in the FME gallery) to be used later. It is not necessary to generate a profile-specific mapping file each time a translation is performed.
The following sections describe the specifics of each of the three profiles in more detail.