The general layout of the Guiding system is shown in Figure 5.
A remotely driven XY slide simultaneously moves two coherent optical fibre bundles over the focal plane (see also Figure 4). An area of 30 (2 x 15) is available for guiding purposes. Each bundle has a field of view of 18 x 18 arcsec on the focal plane.
Figure 5: Guiding system
The Guiding unit is equipped with a filter wheel housing up to six filters. The filters must be circular and 25mm in diameter. In the standard configuration the following filters are installed: CLEAR, BG38, GG495, OG530, and RG630.
The two guiding bundles are focussed onto a standard CCD autoguider head with thermoelectric cooler, through a prism and a lens (magnification 1:1).