La Silla - Science Operation Department
With regular intervals the stability of the instrument is monitored. An arc spectrum is taken
with regular intervals during (typically) half a day, and the movements in dispersion and
cross-dispersion directions are measured. In the table below, the shifts are calculated from the
part of the curve with the fastest change rate, hence represents a "worst case".
Recent measurements are accompanied by plots. All measurements were made at 539.5nm.