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WHT Command Glossary

This document is intended as a convenient summary, not an exhaustive reference. See the individual instrument pages for more up-to-date information.

Starting the observing system

Login to taurus as whtobs. Several windows will come up (NB the windows can be dragged across the 3 screens using the mouse).

Type obssys, then startobssys in each of the required orange DAS (data-acquisition) windows.

Type obssys, then startobssys in the pink SYS (or TO) window.

To change configuration, type obssys, then 1 then c, then edit the configuration file.

To shut down, type shutdownobssys.

To start an iraf session, click on the xgterm icon at the left of the screen to bring up an xgterm window, then type ecl (better than cl, because it allows normal use of the rubout and up-arrow keys). To bring up the ds9 display tool, type !ds9 & at the iraf prompt.

startrtd bring up the INGRID realtime display

Data acquisition

(Last reviewed 9/07) Consult the ultradas manual for details.

ch = channel name e.g. red, blue, aux, pfip, oasis, ingrid

Taking exposures
run    ch t title take an exposure (title optional, should be in quotes
                  if it includes spaces)
                  NB run 0 opens shutter and closes it, use bias instead.
flat   ch t title take a flat-field exposure
sky    ch t title take a sky-flat exposure
arc    ch t title take an arc-lamp exposure (doesn't control arc lamps)
dark   ch t title take a dark exposure (shutter not opened)
bias   ch   title take a bias frame 
flash  ch   title take zero-sec exposure with preflash

The above differ mainly in writing different values to FITS headers 
such as OBSTYPE.

multrun ch n t title  
                  take n exposures
                  (the commands multflat, multsky, multbias etc. 
                  take similar syntax)
scratch ch num t title
                  take exposure with file-number num.
glance ch t       take exposure without headers, for quick look

shutter ch state  where state = open or closed

bin    ch nx ny   bin CCD nx in x direction, ny in y direction
rspeed ch fast    set readout speed, fast or slow
geometry ch       show CCD geometry, location of bias strips etc.
window ch 1 "[800:1200,1:4200]" 
                  set size of window 1 
window ch 1 disable  
                  disable window
window ch 1 enable  
                  enable window

saveccd ch file   save bin, speed and window settings to a named file
setccd ch file    restore above settings from named file
unsetccd ch       restore default settings (those applied on system startup)

setoasis          set up standard OASIS windows
oaw1, oaw2        select oasis windows 1 or 2

Focus procedures
focusrun ch n t f0 df
                  take series of n images on channel ch, stepping focus
                  position by df between images (start focus position f0)
                  e.g. focusrun red 9 5 97.7 0.05
                  For reference, a change of focus of 0.1 mm at the
                  f/2.8 prime focus gives a defocus of 0.036 mm or
                  0.8 arcsec.
                  At the f/11 Cass or Nasmyth focus, a change of focus
                  of 0.1 mm translates to a shift in the focal plane of
                  2 mm, corresponding to a defocus of 0.18 mm or 0.8 arcsec.

NB the old quickfocus command (which analysed the data) does not work
(under CORBA, which replaced DRAMA).
Example observing script
Type the following into a file, e.g. run3c

gocat 3c$2
echo "Hit return when acquired"
read name
run red $1; bell &
run blue $1; bell & 

Type chmod 755 run3c to make the file executable.
Now, to go to a target named 3c121, pause while the operator acquires 
it on the ISIS slit, run 1800-sec exposures on each of the red and blue arms,
and terminate with a loud ping, type:

run3c 1800 121

The #!/bin/tcsh on the first line of the script is formally required 
to tell the computer that the script is running within the 
enhanced C shell.
If you omit the line, the script will run within the default shell,
which on taurus, when logged in as whtobs, is 'sh' = Bourne shell.
For most scripts, it's unlikely to make much difference which shell
you use.
See for a discussion
of the 'shebang' = '#!'.

abort ch          terminate exposure early and abandon data 
bell              sounds bell, useful e.g. in run wyffos 1000; bell &
dasreset ch       restart the camera
finish ch         terminate exposure early and keep data
newtime ch t      set new exposure time
obsdata EEV12 /obsdata/whta
                  explicitly set partition to which data are written
                  (useful when system has defaulted to use a disk
                  you don't want your data on - check at start of night)
udas_camera_mimic EEV12 &
                  brings up the green camera mimic window for EEV12

Data inspection - iraf

If an iraf session isn't already running on the instrument-control screens (or if for some reason you need to restart it, e.g. after an imexam failure), open an xterm window on whticsdisplay1 and type iraf. An iraf (ecl) window and ds9 display should start up automatically.

To start up an iraf session on another computer at the WHT, e.g. the data-reduction computer whtdrpc whose screen is to the right of the instrument-control screens, log in as whtguest, bring up an xgterm window, type cd to go to the home directory, then ecl to bring up iraf. A ds9 image display can be brought up from the ecl prompt by typing !ds9&.

The iraf loads useful packages including onedspec, twodspec, apextract, ing and ingrid.

Examples of especially useful iraf commands:

  • display[1] 1 fil+ to display an image
  • imexa to examine an image - once a cursor appears in the image, type one of the following:
    • a - aperture photometry
    • c - vertical cut
    • e - contour plot
    • h - histogram
    • j - gaussian fit in x direction
    • k - guassian fit in y direction
    • l - horizontal cut
    • m - mean, median, rms
    • r - radial profile, 3 measures of fwhm
    • s - surface plot
    • v - hit v at 2 points on image for a cut between them
  • display[1] 1 fil+; imexa

To make the ing package of iraf scripts available, type ing, then e.g. ingrid for ingrid scripts (e.g. idisp to display ingrid images)

Observing log

To add a comment, click on the relevant line in the log.

If the log window disappears, it can be re-opened by typing

obslog &

at the instrument-control prompt (pink window).

At the end of the night, store the log by clicking on 'night report'. Click on 'change date' to see the log for another night.

Writing data

  • Obtain DVD (4.7 Gb) from telescope operator or support astronomer
  • Go to cfgpc7 console in the computer area adjacent to the control room, login as whtobs
  • Move to the data directory e.g. /obsdata/whtd/20070914
  • Follow the instructions on cfgpc7 for writing the DVD

Cassegrain A& G

(Last reviewed Sep 2007, source WHT A&G system user guide)

Type command-name and return, for help on those commands taking parameters.

A&G mirrors
agmirror out      remove all mirrors
agingrid          put in flat to feed A&G aux port 2 (opposite 
                  aux port), e.g. AG2, equiv to agmirror ingrid
                  or agmirror largefeed
                  (NB INGRID never now mounted on this port)
agcomp            move mirror to acquisition/comparison lamp position
agslit            move mirror to slit-viewing position (and switches
                  off the calinration lamps if they are on)
agaux             equivalent to agmirror smallfeed (for auxiliary focus 
compmirror state  state = in or out 

A&G filters
mainfiltnd name   main filter slide to OUT, 2, 3, 4, 5, 6 (see whiteboard)
mainfiltc name    main filter colour to OUT, 2, 3, 4, 5, 6 (see whiteboard)
mainfilta         new name for above?
mainfiltb         "    "

Aux-port imager
auxfilter n       select auxiliary focus filter  n, 1-6 (see MIMIC for
                  details of filters in wheel), or by name
auxlamps name     turn on AUXCUAR or AUXW lamps for auxport
                  (COMPLAMPS OFF to turn off).  Not now in use.

tvfocus n         moves TV focus to  n (14000 for 5 arcsec/mm, 12750 for 
                  12 arcsec/mm for slit-viewing)
tvfilt name       TV filter to CLEAR, B, V, R or EMPTY (= OPAQUE)
tvscale s         select TV scales of  s = ~5 or 12 arcsec/mm 
                  (1.5 or 4 arcmin field)

N.B. The two TV scales need slightly different TV focus settings. 

settv f/mode      sets mirror and TV focal reducer, where f = 5 or 12
                  (5 or 12 arcsec/mm) and mode = slit or direct
tvslit5           standard slit-viewing, 5 arcsec/mm
tvslit12          same, 12 arcsec/mm
tvdirect5         on-axis viewing (not reflected from slit jaws), 5 arcsec/mm
tvdirect12        same, 12 arcsec/mm

Calibration lamps
complamps name    turn on lamp (cuar, cune, cuar+cune, w) or off
compfilta name    put in CLEAR, ND0.2, ND0.6, ND0.8, ND1.8, ND3.0,
                  GG375, GG495
compfiltb name    put in CLEAR, ND0.3, ND0.5, ND0.9, ND1.2, ND2.0, BG24,
compnd n          put in closest approximation to ND n (0 - 3) it can

cuaron            procedure to put in comparison mirror and turn CUAR on
cuneon            same but for CUNE
Superceded: (?)
ARCOFF            turn lamps off and returns to slit viewing

prag r theta      set probe position in r and theta
autoradial r      r=0-40000 microns
autotheta theta   theta=0-180000 millidegrees
                  N.B. for values below 35000, the probe may vignet the slit
autofocus n       n=0-6000 microns (typically 1500-2500)
autofilt filt     select EMPTY, CLEAR, OPAQUE, B, V or I (can also select
                  by number)

agdoor open/close Unlock or lock A&G filter access door

agvalues          report A&G mechanisms status
AGUPDATE mechanism updates MIMIC for given mechanism e.g. AGUPDATE ALL

cagb start/stop   start or stop A&G control system
cagb_cancel -m mech -a action
                  cancel outstanding action, where mech = one of above
                  mechanisms, and action = init, move or stop
cagb_cancel all   cancel all outstanding actions
cagb_cancel ?     list available options
cagb_init -m mechanism  initialise A&G mechanism:
                  TVREDUCER (to init TVSCALE)[5mm] or ALL
                  (synonym = aginit)
cagb_init_all     initialise all A&G mechanisms
cagb_move -m mech position
                  move mechanism to specified position
cagb_stop -m mech stop mechanism
cagb_update -m mech  update value 
cagb_update_all   as above, for all mechs

Autoguider VME commands [old, no longer relevant?]
START-UP and SHUT-DOWN commands can be issued at autoguider terminal (or window).
SETINT n          set integration time for the field in millisecs
FIELD n           do 4 readouts and looks for n stars
SELECT STAR n     select nth brightest star for guiding
GUIDE ON or OFF   start or stop guiding
<<                rotate LUT
+TAU and -TAU     change horizontal scale of guide error display
+SCALE and -SCALE change vertical scale
ACQINT n          n=1000-50000 millisecs (sets acquisition time)
GUIINT n          n=1000-50000 millisecs (sets guiding time, typical 1-2s)
FIELD             take exposures and finds guide star
FON               initiate following by autoguider
                  User should inform TCS of probe position (get from CAGB mimic)
                  AUTOGUIDER ON at TCS to initiate closed-loop autoguiding
                  AUTOGUIDER OFF at TCS to stop autoguiding
FOFF              terminate following

(For simulated star, FILT=OPAQUE, THETA=60000, RADIAL=20000, FOCUS=2700)
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(Last reviewed 9/07)

Type command-name and return (or '?') for help on commands taking parameters.

slit w            set slit width to w microns (25 - 5000)
slitarc w         set slit width to w arcsec

dekker  n         move dekker to position  n (1 - 9), where for standard 
                  ISIS dekker:
                  1=out; 2=narrow (1.2"); 3=20"(for FOS); 7=long slit
setdekkerset x    set dekker name (x = standard or x = polarisation)

slit_door open    release slit area access door (e.g. to change dichroic)
                  dekker should be in position 1 for access to the slit area
slit_door close   lock slit area access door

rfold  n          move red fold to position  n (0=flat; 1=out)
bfold  n          move blue fold to position  n (0=out; 1=flat; 2=dichroic)

rhart  n          move red Hartmann shutter to position  n
                        0=both out; 1=L in,R out; 2=L out,R in;  3=both in
                  (or out=both out; L=L in,R out; 2=L out,R in; LR=both in)
bhart  n          move blue Hartmann to position  n (same convention)

rcoll  n          move red collimator to setting  n (0 - 30000)
bcoll  n          move blue collimator to setting  n

rfilta  n         move red filter A to position  n (1 - 3)
rfiltb  n         move red filter B to position n (1 - 3)
bfilta  n         move blue filter A to position  n (1 - 3)
bfiltb  n         move blue filter B to position  n (1 - 3)

setgrating arm g  change grating name (with option of moving grating
                  to park position, and unlocking door, to allow it
                  to be changed)
                  arm = red or blue; g = grating name
                  beware r316r but r300b
                  don't use '&' after this command
setgratingoffset arm offset
                  set grating offset (added to grating angle deduced from
                  wavelength).  arm = red or blue.
setgratingorder arm order
                  set order of grating required on detctor at given
                  wavelength.  am = red or blue.
rgrat theta       move red grating to angle theta (units of 0.001 degs,
                  or 0.01 deg according to ISIS control system guide)
bgrat theta       move blue grating to angle theta
cenwave red wave  move red grating to wavelength wave (A)
cenwave blue wave move blue grating to wavelength wave (A)

imageslicer       move image slicer into light path (moves slit mechanism)
                  unlock slit door, position dekker out, allow change of 
isis_filters      display positions of all filters within ISIS
longslit          select long slit unit
mslit             select image-slicer position (formerly multi-slit)
setdichroic 6100  set dichroic name = 6100
setfocus mode     set mode mfor automatic focus correction when either
                  of polarisation waveplate slides are moved in or out
                  of the optical path.  mode = none, tv, telescope or both.

isis start/stop   start or stop *all* isis-related software
isis_begin        ensure mechanism status up-to-date
isis_end          executed by system when ISIS control system shut down
isis_move -m mech position
isis_reprogram -m mech           
                  reprogram SMDM box       
isis_stop -m mech stop mechanism
  ISIS mechanism names include: bluecoll, bluefiltera, bluefilterb,
  bluefold, blue_grating, fcptray, redcoll, redfiltera, redfilterb,
  redfold, red_grating, slitunit, all
 (and dekker, slit_unit?)

Initialising ISIS mechanisms
inslit            initialise slit unit
inrg              initialise red grating
inbg              initialise blue grating
inrfold           initialise red fold
inbfold           initialise blue fold
inrcoll           initialise red collimator
inbcoll           initialise blue collimator
inhw              initialise 1/2 wave plate
inqw              initialise 1/4 wave plate
infcp             initialise FCP tray
indek -m          initialise dekker
isis_init mechanism   
                  initialise mechanism (e.g. one not listed above)

iraf scripts
To analyse data taken for focus/rotation etc. of the CCD, type ing
within an iraf session, then:
isis_udas_focus      measure required focus shift
isis_udas_tilt       measure required cryostat tilt
isis_udas_rotation   measure required cryostat rotation

GRATING_DOOR OPEN unlock both grating doors
                  Do  not issue this command until gratings have reached 35000
                  lock both grating doors. NB: Use CHANGE to change
                  gratings; these commands to reset the doors only.
mechanism INIT    another way to initialise. Note that
                  mechanism may have an unfamiliar name
                  e.g. RFILTA INIT

ISIS polarisation module
hwin              = HW_POLAR MOVE IN      move half-wave plate in
hwout             = HW_POLAR MOVE OUT     move half-wave plate out
hwp               = HW_POLAR angle        move HWP to requested angle (0 - 360)
hwprot rate       = HW_POLAR ROTATE rate  rotate HWP at requested rate (Hz)
                                          (range 0 - 1)
hwstop                                    stop rotation of HWP

qwin              = QW_POLAR MOVE IN      move quarter-wave plate in
qwout             = QW_POLAR MOVE OUT     move quarter-wave plate out
qwp               = QW_POLAR angle        move QWP to requested angle
qwprot rate       = QW_POLAR ROTATE rate  rotate QWP at requested rate (Hz)
qwstop                                    stop rotation of QWP

settopwaveplate qw or hw
                  identify top waveplate

fcp clear or field_lens or polaroid or calcite 
                  move polarisation component into beam
fcp_out           synonym for FCP CLEAR

lpol arm time "title" 
                  take 4 expsores with the HWP at angles 0 45 225. 67.5
cpol arm time "title" 
                  take 4 expsores with the QWP at which angles???
(lpol and cpol have been superceded?)

isisp_begin to recover ISIS pol unit
isisp_move -m mech position
isisp_init -m mech  
                  initialise named ISIS pol mechanism, where mech is one
                  of phwspin,pqwspin,phwangle,pqwangle,pqwslide,phwslide
isisp_stop -m mech
                  stop mechanism
isisp_update -m mech
                  update status of mechanism

ISIS pol superceded?
pol               synonym for FCP POLAROID
SIO FLENS_CALC_POL MOVE 3 (or 0) to move calcite block in (or out).
???               indicate wave-plate mount  locations (select
                  ISISP waveplate mountings)

Initialising ISIS polarisation module
INHW              initialise half-wave plate
INQW              initialise quarter-wave plate
ISISP_INIT        initialise polarisation unit

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Prime-focus imaging

pfilter filter        put requested filter (number or name) in the beam
                      (in scripts, use the following command)
pfip_move -m filter   put requested filter in beam
pfip_move -m autofilt move autoguider filter wheel to requested position

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These are the old names, now superceded...

HELP AF2         get help on commands
AFSETUP          set up AF2 
AFACQ            acquire field
AFALLCIRCLE 0    place all fibres in large circle
AFALLPARK        park all fibres
AFMAP            map distortions
AFCONFIG         run configuratyion program
AFTELLP          update robot position
AFTELLS          return status
AFTELLF n        return info on fibre n (0 - 160)
AFMOVP n         move off-axis sky probe, p is what?? (0 - 150000)
AFPARKR          park robot carriage safely
AFOFFSETR dx dy  offset xy carriage by dx, dy
AFQUAD n         offset robot into specified quadrant
AFVIEWS x y      position mobile probe at x, y (-200000 - 200000)
AFVIEWO n        position mobile probe above fibre n 
AFVIEWF n        position fibre viewing camera above fibre n (1 - 160)
AFPARKF n        park fibre n (1 - 160)
AFMOVF n x y     move fibre n (1 - 160) to x,y (-140000 - 140000)
AFITER n         change number of putdown iterations to n (0 - 9)
AFTOL n          change positioning tolerance to n microns (0 - 120)
AFDISAB n        temporarily disable fibre n (0 - 160)
AFENAB n         enable fibre n (0 - 160)
AFBACK ON or OFF switch fibre back illumination on or off
AFLIG ON or OFF  switch instrument inspection lights on or off
AF2_EXTRACT      extract AUTOFIB from a limit switch if possible
AFSLEEP          put AUTOFIB into sleep mode (including parking robot)
AFWAKE           wake AUTOFIB from sleep mode
AFRECOVER n      find fibre that was last moved (to recover if wrongly placed)

WCHANGE grating  change name of grating e.g. to R1200B (affects
                 calculation of central wavelength)
WCENWAVE w (n)   set grating for wavelength w (order n, for echelle)
WFILTA pos       move filter slide A
WFILTB pos       move filter slide B
WSLITF pos       set slit focus position
WCAL n state     set calibration lamp number n to state ON or OFF
                 WCAL OFF to turn off lamps
WFIB state       control AF2 fibre back-illumination state ON or OFF
WCHANGE          change grating or filter(s)
DOWAIT/NOWAIT    set whether commands wait for completion
WGRAT angle      set grating to angle (mdeg)
WSETFOC state    control filter focus compensation (ON or OFF)
WHART state      set Hartmann shutters L, R, LR or OUT
WNITRO state     set nitrogen flush ON or OFF
WSLITT pos       set slit translation position (microns)
WCFILTA pos      calib unit filter A
WCFILTB pos      calib unit filter B

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Telescope control system

See section 2 of the TCS user manual (blue binder) for a classified list of commands. Some of the telescope-control commands can be issued at the instrument-control interface. Some require the form:
  user "command"
  tcsuser "command"
*** The telescope must NOT be moved without checking with the telescope operator ***

Useful commands:

tcsinfo &        bring up copy of TCS info page (showing current WHT
                 pointing, whether tracking etc.)

focus 97.55      change tel focus

gocat 3c121      go to source 3c121

object name hh mm ss.s dd mm ss j2000
                 enter object name (equinox can be e.g. b1950, j2000)
                 NB proper motions cannot be specified with this command

user "rot mount 0"  set PA of rotator

user "rot sky 0" set sky PA = 0

offset arc ra dra 
                 offset telescope in RA, dec by ra, dra arcsec

user "enter aperture n xoff yoff"
                 define 'aperture' n (xoff and yoff are the offsets
                 in arcsec, in the instrument coordinate system)

user "tweak xoff yoff PAoff"
                 offsets telescope, keeping the guiding loop closed.
                 The size of the offset is limited by the field of view
                 of the autoguider.

online TCS@lpas4  
                 restore TCS communications from the observing system

tcsuser "page dome"
                 changes the page of info displayed on the TCS
                 status window (or a clone of it, started with
                 tcsinfo &), so that observer can see status of
                 the mirror petals and the mirror flat.

tcsuser "page info"
                 restores the usual page of info on the
                 TCS status window

To load a catalogue of target positions, start an xterm on taurus
(the instrument-control computer), copy the catalogue e.g.
(must end in .cat) to /wht/cat, and type at the TCS control window:

include fred

Top-end lamps, mirror petals

fflamp [1-5 | ALL | -h] [on | off] (lamps on or off)

fflampspwm [1-100 | -h] (sets lamp intensity; 'pwm' stands for pulse-width modulation)

For example:

fflamp 2 on (switches lamp 2 on)

fflamp all off (switches all lamps off)

fflamp -h (on-line help)

fflampspwm 50 (set lamp intensity to 50%)

petals open (open M1 petals)

petals close (close M1 petals)

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Click here for WHT home page

Original version: 1995 Oct 11, last revised 2012 Feb 8

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Last modified: 17 September 2015