The wavelength calibration and resolution of the SWS.
Lutz, D.; Heras, A. M.; Beintema, D. A.; de Graauw, T.; Feuchtgruber, H.; Morris, P. W.; Salama, A.; Barr, P.; Roelfsema, P. R.; Luinge, W.; Vandenbussche, B.; Lahuis, F.; Haser, L. N.; Bauer, O. H.; Boxhoorn, D. R.; Katterloher, R. O.; Kester, D. J. M.; Schaeidt, S. G.; Valentijn, E. A.; Wieprecht, E.; Wildeman, K. J.; Spoon, H. W. W.; Leech, K. J.; Heske, A.
Abstract
The laboratory wavelength calibration of the SWS has been succesfully transferred to the in orbit situation. The achieved accuracies for the grating sections are λ/δλ~10000. Any remaining errors in the wavelength scale are dominated by uncertainties of the relative position of the target in the 14"-20" wide slits. The grating spectral profile is very well represented by a Gaussian shape. The width of the grating spectral profile can be accurately predicted by a theoretical model. The wavelength calibration of the FP's is accurate to within 1/3 of a resolution element, corresponding to λ/δλ~10^5^. The wavelength stability of the gratings and FP is excellent, no measurable changes were found during the first 6 months of the ISO mission.