Geodetic Data Catalog Files
MicroStation PowerDraft uses the concept of a Geodetic data catalog to determine the location and file names of files to be used for a specific grid shift calculation. For example, the data files used to convert NAD27 to NAD83 and vice versa must be individually listed in a data catalog file. While this introduces some inconveniences, it solves several problems such as:
- case sensitive file names
- multiple copies of large data files
- controlling file precedence
- supporting different datum conversions covering the same geography.
The remainder of this section is devoted to describing data catalog files.