Re-Fid a Channel

Use the Database Tools > Channel Tools > Re-Fid a Channel menu option (REFID GX) to change the fiducial sampling of a channel based on a reference channel. This is typically done to resample a database using a distance channel, in which case the new fiducial represents distance.

The option is also available under 1D FFT > Advanced Settings > Re-Fid Back to Fiducial.

Re-Fid a Channel dialog options

Channel to re-fid	Select the data channel to be resampled. Script Parameter: REFID.IN
Resampled output channel	Specify the new resampled output channel. Script Parameter: REFID.OUT
Fid reference channel	Select the fiducial reference channel. Script Parameter: REFID.REF
New start fiducial	Enter the new start fiducial. Leave blank to use the default (the smallest value in the reference channel). Script Parameter: REFID.START
New fiducial increment	Enter the new data increment. Leave blank to use the default (the nominal increment of the reference channel). Script Parameter: REFID.INCR
Maximum gap to interpolate	Specify the maximum gap to interpolate. Gaps larger than this will not be interpolated. Default: 1.5 × data increment Script Parameter: REFID.GAP
Interpolation method	Choose the interpolation method: Linear, Minimum Curvature, Akima, or Nearest. Script Parameter: REFID.METHOD

Application Notes

The new channel should only be viewed or processed with other channels resampled using the same reference channel.

Example: To work with a data channel using evenly spaced ground units, first create a distance channel using DISTCHAN GX. Then resample the X, Y, and data channels to the desired increment. The X, Y, and data fiducials will now represent ground distance units.

If you refid a channel, the channel can be resampled relative to other channels or the original fiducial. The system places a red underline beneath the channel name to indicate this.