› Forums › Spectroscopy › What wavelength error is acceptable with an Alpy? › mixed calibration
Hi David,
The ALPY calibration module has always had the NeAr lamp. The link I posted was specifically for calibration the ALPY. The first line used in the ALPY calibration is 3946.1 and the calibration deteriorates below there. eg
http://www.astrosurf.com/buil/isis/guide_alpy/calibration/fig_fr22.png
What is the first line you use with the LISA? (note some lines which might be resolved at the LISA resolution could be blends with the ALPY so not useable)
When calibrating the ALPY with the NeAr lamp, ISIS definitely reports the fit values not the published values. You can see examples on the page linked. For example
http://www.astrosurf.com/buil/isis/guide_alpy/calibration/fig_fr19.png
and for a bad calibration
http://www.astrosurf.com/buil/isis/guide_alpy/calibration/fig_fr23.png
Cheers
Robin