Changes
/* For IRAF users */
** Use the QL output as a reference. For example, a useful way is to plot the ascii wavelength solution in some interactive plotting window, like python.
** Then simply, select a few bright, well-spaced lines, hover the cursor over them, and read off the wavelength coordinate.
** Now, run '''IRAF - twodspec - identify ''' on the corresponding raw 2D image. Select the same line and input its wavelength as just read off the plot. The solution is good to within a couple of Angstroms, and there are sufficient lines in the arcs that this should work well.
** Repeat for several lines.
** When happy, automatically add all the lines (press "l").
* Once you have identified the lines in one aperture, repeat for every nth pixel (probably every 5th pixel is fine, the tilt is about 0.6 pixels per pixel) using '''reidentify'''.
* Run '''fitcoords''' on the database produced by reidentify
* Run '''transform''' on the image using the fitcoords database to produce a wavelength-calibrated, rectified 2D arc.
* This solution may now be copied to other images and science data extracted in the standard way!
