• The ICL VAX/VMS computer, which controls both AF2 and WYFFOS. A mimic window is available to check the status of the instrument.
• taurus, a Sun workstation where the data acquisition system (UltraDAS) is run.
• whtdr, another Sun workstation where frames can be displayed and analysed using iraf. Note that if you plan to reduce your data on the fly please consider that you can't operate on the images stored in the /obsdata directory. You can create a directory in the /scratch filesystem (e.g. /scratch/whta/20040110) and copy the images there to proceed.

The commands generally used by visiting astronomers are listed below:

hh:mm:ss> wcenwave xxxx y
sets central wavelength to xxxx angstrom for order y (the latter parameter to be entered only for the echelle mode).

hh:mm:ss> wslitf xxxx
set instrument ("slit") focus to xxxx nm.

hh:mm:ss> wslitt xxxx
sets "slit" translation to xxxx nm.

hh:mm:ss> wfilta in/out
Puts filter A in/out of the beam. The slit focus will be automatically compensated to take into account the filter optical thickness. However, you MUST wait until all actions are completed (filter movement AND focus change, giving TWO messages "Action complete"), before issuing any other command.

hh:mm:ss> wfiltb in/out
The same as above, but for filter B.

Before setting up a field, the corresponding configuration file (.cfg) should be copied into the ICL Vax. From any other ING computer,

> ftp lpvg
enter as observer (password provided by the Support Astronomer (SA))

> cd [.af2]

> ascii

> put name_of_file.cfg.x
where name_of_file.cfg.x is the selected configuration file, prepared using the AF2_configure software.

After copying the configuration file, the field is set by typing the the following ICL commands:

hh:mm:ss> afwake
switches the AF2 robot on

hh:mm:ss> afsleep
switches the robot off. This is recommended after a setup is finished, and is mandatory if working in the far red, as near-IR inspection lights in the robot would cause scattered light to appear in frames.

hh:mm:ss> afsetup name_of_file.cfg;x
sets the configuration contained in file named name_of_file (version x if more than one exists). You will be asked for the SIDEREAL TIME for the configuration: this provides the HOUR ANGLE used to transform sky coordinates into plate coordinates, overriding the value of the parameter "H.A." in the .cfg file.

Note that a complete setup takes about 30 minutes.

hh:mm:ss> afrecover
If a fibre is lost during a setup, try to recover it by issuing this command. If the fibre is recovered, you can restart the setup. If not, try again afrecover, and if it fails again ask for help from the TO, SA or Duty Engineer.

Note that the fibres configuration can be done at any telescope position, as fibres do not move on the plate when telescope is moved. So, it is safe to set in the afternoon the first configuration field used at night. However, as the xy plate coordinate system might have a general drift with large telescope movements, if the same field has to be reconfigured during the night, we suggest to run the ICL command

hh:mm:ss> afloadmodule

(this takes slightly more than 5 min) before reconfiguring the field.

hh:mm:ss> wcal x on
switches on calibration lamp at position x. See the list of currently available lamps.

hh:mm:ss> wcal off
switches calibration lamp off.

The complete list of commands can be found in the UltraDAS dictionary. Some of the most important ones are listed below.

SYS> window wyffos 1 "[1:4300,1:4200]"
windows the CCD mosaic so that both frames are mosaiced into a single frame.

SYS> rspeed wyffos slow/fast
sets readout speed of the camera to slow/fast mode.

SYS> bin wyffos x y
bins camera pixels to x and y values

SYS> bias wyffos
takes one bias

SYS> multbias wyffos n
takes n biases

SYS> run wyffos xxx "title" &
runs (in background) a science exposure of xxx sec, and puts a title in the FITS header.

SYS> multrun wyffos nn xxx "title" &
starts nn science exposures each of xxx seconds.

SYS> abort wyffos
aborts current exposure. No image is saved on disk.

SYS> finish wyffos
stops immediately the current exposure, and the frame is saved on disk.

SYS> newtime wyffos xxx
changes the exposure time of the current exposure to xxx seconds.

The same syntax as for the "run" command is used for the flat (flat fields), arc (arc lamps), sky (sky offsets), with the only difference that the corresponding FITS header is filled with the exposure type.

When a field is setup for the correct Sidereal Time, just give the coordinates of its centre, equinox, and the sky Position Angle to the TO, and he will acquire the field and star guiding. Exposures are defined using the UltraDas commands in the previous section.

Acquiring a standard star

This requires knowing the offset between the gripper centre (where fibre is) and the mobile probe sky viewing camera. To di it, youmust have a field setup ready.

Step 1 (done only once in a run or a night, usually by TO+SA)

This assumes the sequence rot centre, calibrate, aperture offset has been executed successfully by the TO at beginning of run.

- Move the telescope to a relatively bright star;

hh:mm:ss> afwake

hh:mm:ss> afviews 0 0
and centre the star on the probe centre.

hh:mm:ss> afoffset SKYPA STARNAME FIDUCIALFIBRENR
where FIDUCIALFIBRENR is the number of a fiducial fibre inside the field (better close to the centre), SKYPA is the current sky position angle, and STARNAME in any string of characters.
Answer the questions (first 'no' then 'yes'). This offsets the telescope to ideally put the fiducial fibre on the top of the star, and also moves the mobile probe to see the star.

hh:mm:ss> afpark
remove the mobile probe, and centre accurately the star on the fiducial bundle using acquisition camera.

hh:mm:ss> afviewo FIDUCIALFIBERNR
(same fiducial fiber nr as above). See where the star ends up on the mobile probe sky viewing image, and mark its position with a cross. This cross reflects the gripper centre. When acquiring another field or standard, use this cross.

Step 2 (done every time you want to observe a standard stars)

- Move the telescope to the standard star;

hh:mm:ss> afoffset SKYPA STARNAME SCIENCEFIBRENR
where SCIENCEFIBRENR is the science fibre where you want to obtain the standard spectrum, SKYPA is the current sky position angle, and STARNAME in any string of characters. Answer the questions (first 'no' then 'yes'). Ask the TO to centre the star in the cross marked on the mobile probe camera.

hh:mm:ss> afpark (or afsleep) Park the robot and take an exposure.

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Last Updated: December 2004 Romano Corradi, rcorradi@ing.iac.es