2.11 Single Dish VLBA Observing
SCHED is used primarily to schedule VLBI observations on the VLBA and most of the rest of this
manual is devoted to details of how to do that. However, there are a variety of types of observations
that are rather different. These are mainly single antenna observations usually done to measure system
performance. SCHED is able to make the schedules for these observations. Such observations are not
likely to be of interest to users other than NRAO staff involved in the testing and maintenance of the
instrument.
Some items of special interest for VLBA scheduling are:
-
-
SOURCE:
The
source
name
is
used
in
the
usual
way.
However,
for
pointing,
there
is
a
useful
capability
to
specify
the
name
of
a
Solar
System
object
and
have
SCHED determine
its
location
from
a
JPL
ephemeris.
See
the
description
of
SOURCE
for
more
details.
-
-
OBSTYPE:
This
should
be
set
to
NONE
for
single
dish
observations.
-
-
CALCODE:
If
set
to
“L”,
pointing
data
will
be
processed
using
differences
between
the
on-line
and
off-line
channels.
-
-
PTVLBA:
This
can
be
specified
on
a
scan
basis
and
causes
SCHED to
write
out
a
pointing
pattern.
It
can
be
turned
off
with
NOPTVLBA
-
-
TAVLBA:
This
can
also
be
specific
on
a
scan
basis,
but
not
for
a
scan
with
PTVLBA.
It
is
another
special
mode,
very
similar
to
PTVLBA,
for
measuring
antenna
temperatures.
It
can
be
turned
off
with
NOTAVLBA.
-
-
PN3DB:
This
can
be
specified
on
a
scan
basis
and
causes
SCHED to
write
out
half
power
tracking
test
pattern.
It
can
be
turned
off
with
NOPN3DB
-
-
AZCOLIM:
This
specifies
a
pointing
offset
in
arcminutes
in
the
azimuth
direction.
It
is
equivalent
to
the
term
used
in
the
pointing
equations
to
account
for
feed
offsets
so
it
is
a
constant
angle
on
the
sky.
The
actual
change
in
azimuth
increases
at
high
elevation
because
of
the
cos(El)
dependence
of
the
angular
effect
of
an
azimuth
change.
It
is
available
both
in
the
setup
file
and
in
the
main
schedule.
-
-
ELCOLIM:
This
specifies
a
pointing
offset
in
arcminutes
in
the
elevation
direction.
It
is
equivalent
to
the
term
used
in
the
pointing
equations
to
account
for
feed
offsets
and
encoder
offsets,
which
are
equivalent
for
elevation.
It
is
in
the
setup
file.
-
-
PTINCR:
This
is
the
jump
in
arc
minutes
between
the
on-source
and
half-power
pointing
positions
for
use
in
setting
up
pointing
patterns.
It
is
used
in
PTVLBA,
PN3DB
and
TAVLBA
modes.
This
is
a
setup
file
parameter.
-
-
PTOFF:
This
is
the
jump
in
arc
minutes
between
the
on-source
and
off-source
pointing
positions
for
use
in
setting
up
pointing
patterns.
It
is
used
in
PTVLBA,
PN3DB,
and
TAVLBA
modes.
The
default
is
6
times
PTINCR.
This
is
a
setup
file
parameter.
-
-
PTDUR:
This
parameter
is
a
time
(in
the
usual
time
format)
that
specifies
the
time
spent
in
each
pointing
position
of
a
pointing
pattern.
A
reasonable
value
is
15
seconds.
-
-
PTSLEW:
This
parameter
specifies
the
time
to
allow
to
slew
to
the
source.
It
is
specified
in
the
usual
time
units
(seconds).
With
dwell
time
scheduling
or
schedule
optimization,
it
should
be
kept
small,
often
equal
to
PTDUR.
-
-
FOCUS:
This
is
used
to
increment
the
subreflector
focus
position.
The
value
is
added
to
the
nominal
value
known
to
the
on-line
system
for
the
particular
receiver.
-
-
ROTATION:
This
is
used
to
increment
the
subreflector
rotation
position.
The
value
is
added
to
the
nominal
value
known
to
the
on-line
system
for
the
particular
receiver.
-
-
ROTPAT:
This
triggers
generation
of
a
focus-rotation
test
pattern
of
pointing
observations.
-
-
ROTOFF:
This
is
used
to
specify
the
rotation
offset
positions
of
a
focus-rotation
pattern.
-
-
FOCOFF:
This
is
used
to
specify
the
focus
offset
positions
of
a
focus-rotation
pattern.
-
-
EPHFILE:
This
is
the
name
of
the
ephemeris
file
to
use
if
planets
are
included
in
the
pointing,
as
they
typically
are
at
high
frequencies.
At
the
AOC,
the
ephemeris
files
are
typically
kept
in
a
directory
assigned
the
environment
variable
PLANET_DATA.
That
assignment
can
depend
on
computer
architecture
because
the
files
are
binary.
There are a number of setup files among the standard setups that are for VLBA test observations.
Those that start with pt are for pointing or antenna temperature observations. Those that start with pc
are for pulse cal tests.
In addition to the above parameters, it is often best to make use of one of the optimization modes to
make the actual schedules. OPTMODE=SCANS is perhaps the most useful. With this mode, only a few
template scans need be specified and SCHED will pick the ones appropriate for use in the desired time
range. Below is an example of a script, including everything necessary to run SCHED on each VLBA
station, for making pointing and gain check observations. This example is at a somewhat higher level of
complexity than most in this document, but it shows what can be done with the program. It actually
makes a different schedule for each station, taking into account the different portions of the sky that
can be seen.
#!/bin/csh
#
# Try with VEX file
#
# ========================================================
# ===== Script to make pointing files for the VLBA =====
# ========================================================
# Set stations to be processed.
# Note that the case used here will appear in the sum and
# vex file names, so it is better to use lower.
# The schedules need to be different depending on whether
# a 3mm receiver is present.
# Examples:
# set stalist_3mm="hn nl fd la pt kp ov mk"
# set stalist_no3mm="br sc"
# set stalist_no3mm="" eg use blank if no stations of this type.
set stalist_3mm="pt hn"
set stalist_no3mm="hn"
#
# Set times and experiment code
#
echo Sched environment variable = $SCHED
echo PLANET_DATA environoment variable = $PLANET_DATA
cat <<eofp >! times.par
year = 1996
month = 10
day = 25
start = 0:00:00
opdur = 4:00:00 ! Total project duration
eofp
set expcode="ptg"
# =====================================================================
# =====================================================================
# ====== ======
# ====== Changes not normally needed below this line. ======
# ====== ======
# =====================================================================
# =====================================================================
# Specify the location of the setup files.
#
setenv SETDIR $SCHED/setups
#
# Put much of the generic setup information in ptg_setup.par
#
cat <<eofs >! ptg_setup.par
! ---------------------------------------------------------------------
! SCHED input file setup stuff to be used with pointing proceedure doptg.
! ----- Cover information
version = 1
expt = ’STARTUP pointing’
obstype = PTVLBA
obsmode = ’Multi-frequency pointing observations.’
piname = ’Operations’
phone = ’505 835 7251’
obsphone = ’505 835 7251’
fax = ’505 835 7027’
email = ’vlbaops@nrao.edu’
address1 = ’AOC’
! ----- Catalogs etc.
srcfile = ’$SCHED/catalogs/sources.pointing’
stafile = ’$SCHED/catalogs/stations.dat’
ephfile = ’$PLANET_DATA/JPLEPH.405.2’
!ephfile = ’$SCHED/catalogs/JPLEPH.405.2.Linux’
! ----- Schedule instructions
sumitem = EL1, AZ1 ! Start elevation and azimuth in summary.
ptvlba
ptdur = 15 ! => scan length = ptslew + 2*ptdur + N*10*ptdur
! The autoleveling scan is 2*ptdur long for pcx.
! Here we have 15+30+2*150 = 345s = 5:45
dwell = 5:45
ptslew = 15
optmode = SCANS ! Select scans that are above minimum elevation.
opminel = 20. ! Minimum elevation.
eofs
# Now make a file with the actual schedule info for 3mm sites.
# Any imbedded catalogs etc must be here.
cat <<eofs >! ptg_3mm.par
! ----- Spectral lines
! ----- Set up for 4 channels - 2 on line, 2 off.
lineinit /
lineset =’H2O’ restfreq=22235.08,22235.08,22285.08,22285.08 /
lineset =’SiO431’ restfreq=43122.03,43122.03,43222.03,43222.03 /
lineset =’SiO862’ restfreq=86243.4, 86243.4, 86343.4, 86343.4 /
endlines /
! ----- The detailed schedule
! The frequencies are in an order reasonable for FRM.
! 50/90 cm CYGA, TAUA, 3C274
! 20-4 cm 3C454.3, 3C123, 3C274
! 2, 1 cm DR21, 3C84, 3C274
! 7 mm RCAS, RLEO, WHYA, DR21, 3C84, 3C273, planets
! 3 mm RCAS, RLEO, WHYA, planets
! Group must equal the number of scans below.
! (Group*rep) must be less than 2000 (as of 18 Apr 1996).
! The 7mm line sources used to have qual=50. This used to be the way
! to trigger line processing. Now CALCODE=’L’ does it.
! Note that for a peak=1 scan, no reference pointing will be done
! if the slew takes longer than 40 seconds. That is partly why
! there is a second peak scan.
group=(10*3+8*3) rep=50
setup=’$SETDIR/pt90cm.set’ source ’CYGA’ nodop bw=0,0 /
setup=’$SETDIR/pt4cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt18cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt6cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt13cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt4cmsx.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt1cm.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt24ghz.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt2cm.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’JUPITER’ nodop bw=0,0 qual=0
noptvlba peak=1 dwell=01:00 /
noptvlba peak=1 dwell=01:00 /
nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt3mm.set’ nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt7mm.set’ source ’RCAS’ doppler bw=2,2 qual=0
linename=’SiO431’
noptvlba peak=1 dwell=01:00 /
noptvlba peak=1 dwell=01:00 /
nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt3mm.set’ nopeak ptvlba dwell = 5:45 linename=’SiO862’ /
setup=’$SETDIR/pt90cm.set’ source ’TAUA’ nodop bw=0,0 /
setup=’$SETDIR/pt4cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt18cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt6cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt13cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt4cmsx.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt1cm.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt24ghz.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt2cm.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’RLEO’ doppler bw=2,2 qual=0
linename=’SiO431’
noptvlba peak=1 dwell=01:00 /
noptvlba peak=1 dwell=01:00 /
nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt3mm.set’ nopeak ptvlba dwell = 5:45 linename=’SiO862’ /
setup=’$SETDIR/pt7mm.set’ source ’VENUS’ nodop bw=0,0 qual=0
noptvlba peak=1 dwell=01:00 /
noptvlba peak=1 dwell=01:00 /
nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt3mm.set’ nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt90cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt4cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt18cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt6cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt13cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt4cmsx.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt1cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt24ghz.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt2cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’3C273’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’WHYA’ doppler bw=2,2 qual=0
linename=’SiO431’
noptvlba peak=1 dwell=01:00 /
noptvlba peak=1 dwell=01:00 /
nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt3mm.set’ nopeak ptvlba dwell = 5:45 linename=’SiO862’ /
setup=’$SETDIR/pt7mm.set’ source ’SATURN’ nodop bw=0,0 qual=0
noptvlba peak=1 dwell=01:00 /
noptvlba peak=1 dwell=01:00 /
nopeak ptvlba dwell = 5:45 /
setup=’$SETDIR/pt3mm.set’ nopeak ptvlba dwell = 5:45 /
! ---------------------------------------------------------------------
eofs
# Now make a file with the actual schedule info for sites without 3mm.
# Any imbedded catalogs etc must be here.
cat <<eofs >! ptg_no3mm.par
! ----- Spectral lines
! ----- Set up for 4 channels - 2 on line, 2 off.
lineinit /
lineset =’H2O’ restfreq=22235.08,22235.08,22285.08,22285.08 /
lineset =’SiO431’ restfreq=43122.03,43122.03,43222.03,43222.03 /
lineset =’SiO862’ restfreq=86243.4, 86243.4, 86243.4, 86243.4 /
endlines /
! ----- The detailed schedule
! The frequencies are in an order reasonable for FRM.
! 50/90 cm CYGA, TAUA, 3C274
! 20-4 cm 3C454.3, 3C123, 3C274
! 2, 1 cm DR21, 3C84, 3C274
! 7 mm RCAS, RLEO, WHYA, DR21, 3C84, 3C273, planets
! Group must equal the number of scans below.
! (Group*rep) must be less than 2000 (as of 18 Apr 1996).
! The 7mm line sources used to have qual=50. This used to be the way
! to trigger line processing. Now CALCODE=’L’ does it.
linename=’SiO431’
group=(12*3) rep=60
setup=’$SETDIR/pt90cm.set’ source ’CYGA’ nodop bw=0,0 /
setup=’$SETDIR/pt4cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt18cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt6cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt13cm.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt4cmsx.set’ source ’3C454.3’ nodop bw=0,0 /
setup=’$SETDIR/pt1cm.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt24ghz.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt2cm.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’DR21’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’RCAS’ doppler bw=2,2 qual=0 /
setup=’$SETDIR/pt7mm.set’ source ’JUPITER’ nodop bw=0,0 qual=0 /
setup=’$SETDIR/pt90cm.set’ source ’TAUA’ nodop bw=0,0 /
setup=’$SETDIR/pt4cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt18cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt6cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt13cm.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt4cmsx.set’ source ’3C123’ nodop bw=0,0 /
setup=’$SETDIR/pt1cm.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt24ghz.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt2cm.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’3C84’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’RLEO’ doppler bw=2,2 qual=0 /
setup=’$SETDIR/pt7mm.set’ source ’VENUS’ nodop bw=0,0 qual=0 /
setup=’$SETDIR/pt90cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt4cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt18cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt6cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt13cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt4cmsx.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt1cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt24ghz.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt2cm.set’ source ’3C274’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’3C273’ nodop bw=0,0 /
setup=’$SETDIR/pt7mm.set’ source ’WHYA’ doppler bw=2,2 qual=0 /
setup=’$SETDIR/pt7mm.set’ source ’SATURN’ nodop bw=0,0 qual=0 /
! ---------------------------------------------------------------------
eofs
#
# Now run sched separately for each 3mm station.
#
foreach station ( $stalist_3mm[1*] )
echo station=vlba_$station >! station.par
echo expcode=$expcode >> station.par
$SCHED/bin/sched <<eofst
@times.par
@station.par
@ptg_setup.par
sch = ptg_3mm.par
overwrit /
eofst
#
# Make the sum and vex files station dependent.
#
/bin/mv ptg.sum ptg.$station.sum
/bin/mv ptg.vex ptg.$station.vex
end
#
# Finally run sched separately for each no 3mm station.
#
foreach station ( $stalist_no3mm[1*] )
echo station=vlba_$station >! station.par
echo expcode=$expcode >> station.par
$SCHED/bin/sched <<eofst
@times.par
@station.par
@ptg_setup.par
sch = ptg_no3mm.par
overwrit /
eofst
#
# Make the sum and vex files station dependent.
#
/bin/mv $expcode.sum $expcode.$station.sum
/bin/mv $expcode.vex $expcode.$station.vex
end
#
# Some clean up.
#
#/bin/rm times.par
#/bin/rm ptg_setup.par
#/bin/rm ptg_3mm.par
#/bin/rm ptg_no3mm.par
#/bin/rm station.par
#
# END