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The new Acquisition and Guider Box for the JKT was first tested on the
telescope in 1987 August. It is specifically designed to operate with the
CCD camera and will accept all standard RGO cryostats.
Figure 1 shows the essential features of the instrument.
The main features are as follows:
- A fixed rectangular flat with a circular hole set at 45 degrees to the
optical axis which directs light to a standard RGO autoguider. The field
of view is annular with an outer radius of about 17 arc min. and an elliptical
inner radius of 10 - 13 arc minutes. Stars as faint
as V 13 can be used for guiding but brighter stars are preferred.
The autoguider moves on x,y slides and can examine the offset field
from the flat mirror. It has an acquisition field of 2 arc minutes.
- A standard RGO cryostat is used in conjunction with the A and
G Box. Both RCA and GEC chips are available. The filter wheel is similar
(but not identical to) the INT PF CCD filter wheel. It differs by having
a raised index with a V-shaped indent located between positions 6 and 1.
Details of what sized filters can be accommodated can be found in Appendix
9 along with details of currently available filters.
- Removable arms which contain two grisms for direct spectroscopy
are located above the large flat mirror, in the converging telescope beam.
The 'blue' and 'red' grisms give a dispersion of 460 Å ngstroms
per mm (equivalent to 10.2 Å per pixel) but may be used in other orders.
- An ISEC TV which gives a field of view of about 9.5 x 7.5 arc min via
an f/15 to f/7 converter lens and a moving small flat mirror which is placed in
the on-axis beam to allow the TV camera to view the sky directly for
field verification. Objects with V 15 can be seen in direct
mode and V 20 at full integration in a dark sky.
- A mechanical drift scan table on which the CCD cryostat is mounted
and which allows the CCD chip to be scanned across the
field of view whilst the telescope is tracking.
- A MIMIC display is available showing the current positions of all
the movable components of the A and G Box with respect to the box itself.
Figure 2 shows a typical display. The MIMIC display is NOT updated when
drift scanning is in operation.
Previous: OPERATION OF THE JKT A AND G BOX
Up: OPERATION OF THE JKT A AND G BOX
Next: INSTRUMENTAL ALIGNMENTS
Previous Page: OPERATION OF THE JKT A AND G BOX
Next Page: INSTRUMENTAL ALIGNMENTS