2  CDS


cds.gif
Figure 1: The optical layout of the CDS instrument.

The CDS instrument (Figure 1) consists of a Wolter-Schwartzschild type II grazing incidence telescope, a scan mirror, a set of different slits, and two spectrometers that do not observe simultaneously, the normal incidence spectrometer (NIS) and the grazing incidence spectrometer (GIS).