A typical command specifies a channel
(PFIP or AUX); an exposure time t
(sec); a title; an
observation type obstype (e.g., FLAT, BIAS,
TARGET, etc); and sometimes the number num of the output
file in a scratch area. The DAS commands are:
RUNchann t title Take an exposure of an astronomical target
TARGET chann t title Same as RUN
FLAT chann t title Take a flat-field exposure
SKY chann t title Take a sky-flat exposure
DARK chann t title Take a dark exposure (shutter not opened) [4mm] BIAS chann title Take a 0-sec exposure
FLASH chann title Ditto with preflash [4mm] GLANCE chann obstype t A `quicklook' - put data in DMS only (no headers)
KEEP chann title Keep a GLANCE file [4mm] SCRATCH chann num obstype t title. As RUN, but data saved as file num in scratch area
WINK chann num obstype t title. As SCRATCH, but no headers are collected
PROMOTE num Promote scratch file num to normal RUN file status [7mm] It is possible to take a set of n identical exposures with the command [1mm] MULTRUN chann n title [2mm] and there are similar commands MULTFLAT, MULTARC, etc.
DAS commands to modify or end exposures are:
PAUSEchann Pause an exposure
CONTINUE chann Continue a paused exposure
FINISH chann End an exposure and save the data
ABORT chann End an exposure and discard the data
NEWTIME chann t Set a new exposure time
There is a special ICL procedure,
to find the best telescope focus; see Sections 4.5 and 6.4 for more details.
There is an ICL procedure,
to automatically find a guide star from the HST Guide Star Catalog, and move the guide probe to the appropriate place (see Sections 4.6 and 6.3 for more details).
lists the RUN and SCRATCH files taken during the night.