Re-Fid to Distance Reference

Use the Database Tools > Database Utilities > Re-Fid to Distance Reference menu option (REFIDDB GX) to change the Fid (fiducial) sampling of a database to be based on a reference channel. This is normally done to resample a database based on a distance channel, in which case the new fiducial will be distance.

If you wish to simply re-sample the database to give each channel the same fiducial start and increment as a reference channel, use the RESAMPDB GX.

Re-Fid to Distance Reference dialog options

Fid reference channel	Select the Fiducial reference channel. Script Parameter: REFIDDB.REF
New start fiducial	The required new start fiducial. Leave blank to use the default which will be the smallest value in the reference channel. Script Parameter: REFIDDB.START
New fiducial increment	The required new data increment. Leave blank to use the default, which will be the nominal data increment of the reference channel. Script Parameter: REFIDDB.INCR
Maximum gap to interpolate	The gaps in the data larger than this will not be interpolated. The default is 1.5 times the data increment. Script Parameter: REFIDDB.GAP
Interpolation method	The interpolation method to use, one of "Linear", "Minimum Curvature", "Akima" or "Nearest". Script Parameter: REFIDDB.METHOD

Application Notes

The REFIDDB will produce a database with all channels sharing the same fiducial start and increment, and can therefore be used (in most cases) to remove the red bars which indicate that channels are not displayed to their true fiducial indices*. Data will be interpolated, or possibly skipped, in order to make this possible.

For example, if you wish to work with a data channel using evenly sampled ground units, create a distance channel using the DISTCHAN GX, then resample the database to the data increment that you require.

This GX is the equivalent to running the REFID GX on every channel in the database, including the reference channel.

[*The exception to this rule is when a channel has dummy values "*'" in the first cells. In such a case, the REFIDDB tool will only begin at the first non-dummy cell of that channel and thus the result will be a different fiducial start value, compared to a channel that is filled with valid data. Such a channel WILL then have a red bar in the channel header. The workaround is to add any value into the first fiducial row of such a channel before the tool is run.]

As this GX may alter data throughout the database, it is recommended to make a backup of the data first.