Up: Details of SCHED Parameters
OBSTYPE tells SCHED what type of observation this project is.
There are really only four options, although there are several ways
to specify most of them. They are:
- Mark II.
- Specifying either OBSTYPE = MKII or MARKII
causes SCHED to assume that the Mark II recording system will be
used. This system is now obsolete, although maybe not totally gone, so
this should not be common. It causes tape change requests to occur
at time intervals specified by AUTOTAPE and assumes the Mark II
tape is to be left running.
- Wide band recordings.
- Specifying VLBI, VLBA, MKIII or MKIV causes SCHED to assume that the wide band
recorders (tape or disk) are in use. For the wide band recording
modes, the necessary information on tape speed, passes per index
position, etc., is taken from the setup file and the TAPEFILE and the type of recorder to use is based on the
station catalog and the TAPEFILE parameter
MEDIA. If there is a gap between the stop time of one scan and
the start time of tape motion in the next (after taking into account
START, DWELL, GAP, and PRESCAN), then SCHED will insert a
dummy scan with no tape motion (or possibly a rewind or fast-forward)
during this gap. Note that there is no requirement that the
FORMAT in the setup file match which OBSTYP is specified. In fact, it is allowed to mix types at
different stations. For historical reasons, VLBA, MKIII, MKIV, MARKIII and MARKIV are allowed
alternatives with the same effect as VLBI and some of these
appear in the examples.
SCHED does not support Mark III recordings on other than
VLBA systems -- the snap output contains no tape commands. In any case,
Mark III is obsolete and no longer in use.
- Pure VLA observations.
- If OBSTYPE = VLA, SCHED will
assume that only the VLA is being scheduled and that VLBI recorder setup or
commands are required. This is the mode in which SCHED can be used
for many types of VLA scheduling. With the advent of the EVLA project,
SCHED should no longer be used for scheduling pure VLA projects so
this option is basically obsolete.
- Single dish observing.
- OBSTYPE = NONE or PTVLBA
(the default) causes recorder handling to be ignored. This is mainly for
VLBA single dish pointing observations. This does set up the channels
in the Data Aquisition System (BBCs, IF distributers etc), but does
not record VLBI data.
- Configuration studies.
- OBSTYPE = CONFIG causes a map
of station locations to be plotted when plotting uv coverage for
multiple sources. This is mainly for array design
The axis limits are set with parameter
MAPLIM and default to values appropriate
for NMA configuration studies. Continental, national, US state,
and New Mexico roads will also be plotted if the vector files are
available in $PLANET_DATA as they are in Socorro. If you want
to use this capability, you might wish to contact Craig Walker
about details and help -- it is not really meant for general use.
- Argument: Text of up to 8 characters, not case sensitive.
- Options: MKII, MARKII, VLBI, VLBA, MKIII,
MARKIII, MKIV, MARKIV, VLA, PTVLBA,
CONFIG, or NONE.
- Default: NONE
- Usage: Only one value used per project.
- Example: OBSTYPE=MKIII
Up: Details of SCHED Parameters