- APERTURE
- Enter the observing aperture coordinates (arcsec). The default
values are determined by the telescope/focal station combination.
2=to:
2!:}Format: APERTURE x y
2=to:
2!:}Example: APERTURE 10 20
- CATALOGUE
- Enter the name of a source catalogue to be used as a
list of target positions. Standard VMS syntax, defaulting to the current
directory with a .CAT extension.
2=to:
2!:}Format: CATALOGUE filename
2=to:
2!:}Examples: CATALOGUE MANX (uses MANX.CAT in the current
working directory)
2=to:
2!:} CATALOGUE U3:[GUEST01.CATS]JELLICLE.CAT
- CONFIGURATION
- Specify the observing configuration.
The current list of telescope and focal station
combinations is given in Section 4.1.
2=to:
2!:}Format: CONFIGURATION telescope focal_station
2=to:
2!:}Examples: CONFIG INT CASS
2=to:
2!:} CONFIG NONE
- DATE
- Enter the epoch of observation (as a year number, to an accuracy
of 3 decimal places, or in DEC standard format). The default is the current
date and time.
2=to:
2!:}Format: DATE date
2=to:
2!:}Examples: DATE 1994.256
2=to:
2!:} DATE 21-DEC-1995
2=to:
2!:} DATE 25-DEC-1999:22:00:00
- DEFAULT
- Reset the relevant configuration parameters to their default
values. The keywords covered by this command are: DATE,
APERTURE, MAGNITUDE, NUMBER, SEPARATION and
ALL. The default (assumed if no parameter is given) is ALL.
2=to:
2!:}Format: DEFAULT configuration
2=to:
2!:}Examples: DEFAULT MAGNITUDE
2=to:
2!:} DEFAULT
- DEVICE
- Set the GKS device to be used for plotting.
To get a list of workstation names, type DEVICE followed by
? at the _GKS Device name:prompt (not DEVICE ?).
2=to:
2!:}Format: DEVICE GKS_device_name
2=to:
2!:}Example: DEVICE XWINDOWS
The most commonly-used device names are:
- PERICOM_MG
- Pericom graphics terminal.
- CANON_L
- Canon laser-printer (landscape mode). Note that a
device-name of
CANON_L;filename causes the plot output to be written
to a file called filename rather than the usual CANON.DAT. Canon graphics
can be printed on La Palma using the commands WHT_GLASE and
INT_Glase.
- CANON_P
- Canon laser-printer (portrait mode; output filename as
above).
- POSTSCRIPT_L
- Postscript (landscape mode). Again, specifying
POSTSCRIPT_L;filename generates output in filename, rather than the
generic GKS_72.PS. Postscript output can be printed on La Palma using the
command WHT_PLASE.
- POSTSCRIPT_P
- Postscript (portrait mode; output filename as above).
- XWINDOWS
- X-window on VaxStation, Sun or X-terminal. Note that
to get a window on a remote workstation, the command XDISPLAY
should be issued at the $ prompt before starting GSS. This is a
Starlink command, and to use it you will need to execute the appropriate
login procedure by typing (or including in your LOGIN.COM file) the
command @SSC:LOGIN.
- MAGNITUDE
- Set the bright and faint V magnitude limits.
The default values are the standard values for the configuration. The allowed
range is 5 - 19 (there are no stars in the GSC with magnitudes outside these
limits).
2=to:
2!:}Format: MAGNITUDE V V
2=to:
2!:}Example: MAGNITUDE 12 15
- NUMBER
- Set the maximum number of guide stars to be selected at a given
position angle. Overrides system default (50 for NONE; 10 for all other
configurations).
2=to:
2!:}Format: NUMBER max_number
2=to:
2!:}Examples: NUMBER 45
- ROTATOR
- Input the sky position angle, as given to the relevant
telescope control system, in degrees ( - ) or specify that
guide stars be found for all possible position angles using the keyword
ANY. The latter option is meant for small fields, where there may only be a
limited choice of guide stars, in order to allow a sensible choice of rotator
PA. It is disabled for WHT and INT Prime and for the JKT Wide-Field Camera.
2=to:
2!:}Format: ROTATOR angle or
2=to:
2!:} ROTATOR ANY
2=to:
2!:}Examples: ROTATOR 180
- SEPARATION
- Set the minimum separation of guide stars (arcsec).
Overrides system default (5 arcsec for telescope configurations; zero for
NONE).
2=to:
2!:}Format: SEPARATION min_separation
2=to:
2!:}Example: SEPARATION 2