JKT, JAG, and CCD-imaging overview

As of 1998 the JKT is a single-instrument telescope, that can only be used for CCD-imaging. The night-time engineering support is minimal; there is no Telescope Operator, and the Duty Engineer is only available if the WHT or INT do not require his/her attention. You will be assisted by your Support Astronomer for the first part of the first night of your observing run.

The JKT is operated east of pier, with the f/15 secondary, and with the JKT Acquisition and Guiding unit (JAG) mounted at Cassegrain. The JAG holds the autoguider, the acquisition TV, the CCD shutter, and the filter wheel with 6 slots for 50x50mm filters. When the acquisition TV is in use, the light path to the CCD is blocked.

The CCD cryostat is mounted under the JAG. Currently, the default detector is SITe2, a device with 2048x2048 24$\mu$m pixels. For SITe2 the image scale is 0.33 arcsec/pixel, giving an unvignetted field of view of about 10x10 arcmin. A future CCD might be a 2048x4200 13.5$\mu$m pixel EEV device.

 

Figure 1: Schematic view of the JKT east of pier, as seen from the north (a) and west (b)

From July 1998 the JKT will be operated using new software systems: an Alpha-based Telescope Control System (TCS), a Sparc-based Instrument Control (ICS) system, and a Sparc-based Data Acquisition System (DAS). These systems are designed to be operated by just one visiting astronomer, although the JKT control room accommodates the presence of another astronomer.

 

Figure 2: The area of sky accessible to the JKT. Lines of constant zenith distance are drawn on a plot of declination against hour angle. The horizon and hour-angle limits are shown for the two possible cases: (a) Telescope east of the pier (b) Telescope west of the pier

The TCS runs on a VMS-Alpha that can be accessed from an Xterminal in the control room. The ICS and DAS run on two Sparc stations that are also in the control room. Quick data inspection can be done using an IRAF session on one of these Sparc stations. Another terminal is available to access the data analysis Sparc station remotely, in case that a second astronomer needs access to the data.