The IFU profile

The lengths and separations of the images of IFU slices are assumed to be constant. The shifts which are required to align all the spectra in the dispersion direction (x-axis) to an accuracy of $\sim 1$ pixel and to align the slices in the final datacube in the y-axis are also assumed to remain constant. The file ifu_profile.dat in the $ORAC_DATA_CAL directory contains all of these values.

These values should not change (except after physical adjustments of the IFU), though refinements in measurement may well be possible.