fScan Reference Manual, Chapter 2 (CmdLineOptions): timebase
usage: -timebase trs t1map wrtflg t0 u0
With no argument this will cause timepoints for each voxel to be shifted in time as though the data had been recorded at the same time as the first slice. This is done for each voxel (in each slice except the first) by interpolating NZ-1 additional data points (where NZ is the number of slices) between each pair of sampled time points using a quadratic spline function. All time points except the first are then simply replaced by the splined value corresponding to the acquisition time of the first slice.
When specified with arguments, this option allows you to specify uneven TR intervals to set the acquisition times, create a T1 map, and/or use a T1 map to adjust for variable T1 effects. Its args are: