GFIL: Geoid File

Geoid data files can be used to supply geoid undulations and deflections of the vertical to GeoLab computations. This record allows the specification of the name of the geoid specification file (*.GSP) to use (more than one geoid file can be specified by using additional GFIL records). The named file must be a special GeoLab geoid specification file, which in turn refers to the actual geoid data file. Only the geoid values that have not already been defined for the station are actually used (the first record (GEOI or GFIL) defining geoid data for a station is the one actually used).

The format of the GFIL record is as follows:

Columns 002-005: GFIL
Columns 007-070: Path and file name of GeoLab geoid specification file (*.GSP)