3.3 Station Catalog and Locations Catalog
SCHED uses a catalog to get station information such as names, positions, horizons, slew
characteristics and more. This catalog is in keyin format. Station positions may be stored separately in
a Locations Catalog. There are standard Station and Location Catalogs which will almost certainly
have all stations used by a project. SCHED will find these catalogs by default or their locations may
be specified. Any or all of the Station Catalog entries may be given in the main SCHED input if
desired. In any case, the scheduler should consult the catalog to be sure that the right station names
are being used in the schedule. The catalog associated with this release of SCHED is at
$SCHED/catalogs/stations.dat.
SCHED input parameter STAFILE is used to point to any desired external catalog. A file
name of up to 80 characters can be specified. The default is the standard catalog for digital
backends:
STAFILE=$SCHED/catalogs/stations_RDBE.dat. Eventually that will be set back to
STAFILE=$SCHED/catalogs/stations.dat once the conversion of documentation and examples is
complete.
Station catalog information can be given in the main SCHED keyin file. If the keyword STACAT
appears, all input after the next “/” is assumed to consist of station catalog entries until a line
containing the keyword ENDCAT and a “/” is encountered (don’t combine this keyword with a catalog
entry). Such “in-line” catalogs must appear in the SCHED keyin file before the all of the input for
the first scan is complete. This allows the use of station codes to specify stations in each
scan.
Both in-line catalog entries and an external catalog may be used for the station catalog. This
would mainly be useful if there is a non-standard antenna in the schedule. That antenna’s
parameters can be put in the in-line catalog while all other antennas are picked up from the
external catalog. If you wish to prevent SCHED from looking in external catalogs, specify
STAFILE=NONE.
It is only necessary to give one of X, Y, and Z or ELev, LAT, and LONG. The missing set will be calculated.
If both are given, the provided values will be used. If a conversion is done, the WGS84 ellipsoid is used
and the calculations are accurate at the cm level. Since WGS84 is tied to the ITRF, this
should be a good way to convert GPS coordinates to the Earth centered coordinates used in
VLBI.
Some of the information that can be given in the station catalog can also be provided through a
locations catalog. This is mostly position information. The locations catalog can be specified by
LOCFILE. See the description of that parameter for a list of the station parameter that can be in the
locations catalog. SCHED will read and store the locations catalog before reading the
stations catalog. If the station position is missing from the stations catalog, SCHED will
search for a station in the locations catalog with the name specified with DBNAME in the
stations catalog. If a match is found, the associated coordinates will be used. The locations
catalog is used because, in the standard catalogs, the station locations are from the VLBA
correlator data base while all the other information is from other places. It is much easier to
maintain separate catalogs. Users will probably not need to worry about all this, except
perhaps to specify LOCFILE if they keep the SCHED standard catalogs in a non-standard
place.
The parameters of the station catalog are given below. Items that can be in the locations catalog are
noted. Lower case letters are optional. Entries for a station in the Station Catalog are terminated with
a “/”.
Version and station names:
-
VERSION:
-
Catalog
version.
Actually
set
to
the
date
when
all
the
master
catalog
segments
were
last
gathered
to
form
a
full
catalog.
-
STAtion:
-
Station
name.
Up
to
8
characters.
-
STCode:
-
Station
code.
Up
to
3
characters.
Usually
there
are
2
characters.
See
Appendix
A.1
for
a
list
of
codes.
-
DBNAME:
-
The
station
name
used
in
the
VLBA
correlator
data
base.
Might
not
be
the
same
as
STAtion.
DBNAME
is
used
to
associate
entries
in
the
locations
catalog
with
station
catalog
entries.
SCHED uses
STAtion
for
almost
everything
else.
This
name
distinguishes
each
pad
of
the
interferometers.
There
is
a
matching
parameter
with
the
same
name
in
the
locations
catalog.
Up
to
10
characters.
-
DBCODE:
-
The
station
code
used
in
the
VLBA
correlator
data
base.
May
not
be
the
same
as
STCode.
SCHED uses
STCode
for
almost
everything.
This
code
distinguishes
each
pad
of
the
interferometers
so
contains
more
information
than
the
usual
2
letter
codes
given
in
STCode.
Can
be
put
in
the
locations
catalog.
Station location:
-
FRAME:
-
A
character
string
indicating
the
origin
of
the
station
location
information.
Can
be
put
in
the
locations
catalog.
-
ELev:
-
Station
elevation
in
meters
above
(mean?)
sea
level
for
geodetic
coordinates
or
meters
from
the
center
of
the
Earth
for
geocentric
coordinates;
these
cases
are
distinguished
by
value
magnitude.
-
LAT:
-
Station
latitude,
either
geodetic
or
geocentric.
The
format
is
dd:mm:ss.
Positive
in
Northern
Hemisphere.
-
LONG:
-
Station
longitude,
either
geodetic
or
geocentric.
The
format
is
ddd:mm:ss.
Positive
in
Western
Hemisphere.
-
ZALim:
-
Zenith
angle
limit
in
degrees.
Can
be
used
to
limit
elevation
coverage
for
stations
with
other
than
AZEL
mounts.
The
antenna
will
be
assumed
to
point
below
this
limit
to
whatever
limits
are
specified
with
AX1LIM
and
AX2LIM
for
purposes
of
slew
calculations.
However,
if
the
antenna
is
below
this
limit,
the
source
will
be
considered
to
be
down
during
any
optimizations.
-
X:
-
Station
X
coordinate
in
meters.
This
is
in
the
direction
of
the
Greenwich
meridian.
Can
be
put
in
the
locations
catalog.
-
Y:
-
Station
Y
coordinate
in
meters.
This
makes
a
right
handed
coordinate
system
with
X
and
Z.
Can
be
put
in
the
locations
catalog.
-
Z:
-
Station
Z
coordinate
in
meters.
This
is
in
the
direction
of
the
north
pole.
Can
be
put
in
the
locations
catalog.
-
DXDT:
-
Station
rate
of
change
of
the
X
coordinate
in
meters
per
year.
Can
be
put
in
the
locations
catalog.
-
DYDT:
-
Station
rate
of
change
of
the
Y
coordinate
in
meters
per
year.
Can
be
put
in
the
locations
catalog.
-
DZDT:
-
Station
rate
of
change
of
the
Z
coordinate
in
meters
per
year.
Can
be
put
in
the
locations
catalog.
-
EPOCH:
-
The
epoch
in
MJD
at
which
the
X,
Y,
Z
coordinates
apply.
In
other
words,
when
the
offsets
due
to
the
rates
is
zero.
Can
be
put
in
the
locations
catalog.
-
DEScrip:
-
Any
text
up
to
80
characters
(not
used
by
SCHED).
Hardware types:
-
CONtrol:
-
Telescope
control
file
type.
VEX
files
are
produced
for
all
projects
because
most
antennas
are
converting
to
using
them
for
telescope
control
(including
the
VLBA)
and
most
of
the
correlators
(DiFX,
JIVE,
MarkIV)
need
such
files
to
control
correlation.
Other
CONTROL
options
imply
that
other
format
files
are
written
in
addition
to
the
VEX
file.
Valid
option
are
VLBA
for
VLBA
control
files,
VEX
for
stations
that
don’t
need
any
other
formats,
VLA
for
VLA
observe
files
(obsolete),
NONE
for
no
control
file
-
the
default.
A
’V’
in
the
5th
character
will
cause
a
VLBA
control
file
to
be
produced
with
only
the
DAS
(Data
Aquisition
System
—
BBC’s,
formatter,
recorder
etc)
parameters.
It
is
meant
for
cases
with
a
VLBA
style
VLBI
backend,
but
something
else
for
telescope
control.
If
the
first
4
characters
are
VLBA,
this
will
be
the
only
file.
If
they
are
something
else,
both
the
other
type
of
file
and
the
reduced
VLBA
file
will
be
produced.
This
is
the
default
when
CONTROL
=
VLA.
-
DAR:
-
Gives
the
type
of
Data
Acquisition
Rack
present.
This
is
mainly
to
identify
the
type
of
formatter
is
at
the
station
which
will
let
the
program
know
about
the
capabilities
available.
Valid
types
are:
VLBA,
RDBE,
RDBE2,
DBBC,
MKIV,
VLBA4,
MKIII,
S2,
K4,
K5,
VERA,
VSOP,
LBA
and
NONE
(the
default).
Note
that
for
Mark
II
scheduling
(now
obsolete),
any
site
scheduled
will
be
assumed
to
have
Mark
II
equipment.
The
main
non-obvious
option
above
is
VLBA4,
which
is
a
VLBA
DAR
but
with
a
Mark
IV
formatter
installed.
This
will
have
VLBA
BBC’s
and
IF
switching,
but
Mark
IV
formatting
characteristics.
The
RDBE
and
DBBC
are
digital
systems
containing
FPGA
chips
that
can
support
multiple
personalities.
Those
personalities
are
specified
in
the
setup
file
since
they
can
change
between
schedules,
or
even
scans.
The
personalities
are
specified
with
DBE
setup
file
parameter.
The
RDBE2
option
is
the
same
as
the
RDBE
except
that
the
presence
of
2
RDBE
units
is
assumed
allowing
twice
as
many
channels
with
the
DDC
personality.
To
use
2
RDBEs
with
one
MARK5C
unit
required
the
use
of
the
VDIF
format
which
is
not
yet
available
for
the
PFB
personality.
Also
the
PFB
personality
puts
out
a
fixed
2
Gbps
which
is
twice
the
capacity
of
the
current
MARK5C
recorders.
-
DBBCVER:
- Gives the version of the DBBC. Currently supported versions are:
-
ASTRO
is
the
default
DBBCVER.
It
has
4
IFs,
with
the
following
fixed
patching:
ifa=bbc01
to
bbc04;
ifb=bbc05
to
bbc08;
ifc=bbc09
to
bbc12;
ifd=bbc13
to
bbc16.
-
GEO
has
2
IFs
with
the
following
fixed
patching:
ifa=bbc01
to
bbc08;
ifb=bbc09
to
bbc16.
-
HYBRID
has
3
IFs
with
the
following
fixed
patching:
ifa=bbc01
to
bbc04;
ifb=bbc05
to
bbc08;
ifc=bbc09
to
bbc16.
-
RECORDER:
- Gives the type of tape recorder(s) present Valid options are: VLBA, MKIV, VLBA4, MKIII, S2,
K4, K5, VERA, VSOP, MARK5A, MARK5B, MARK5C, and NONE (the default). The VLBA4 option is for
VLBA recorders which have been modified for 16 Mbps per track operation and can be
equipped with 2 recording heads. They are usually associated with MKIV or VLBA4
DARs.
-
NBBC:
- Tells SCHED how many BBC’s or VC’s are at the site.
-
NDRIVES:
- Gives the number of tape drives at the sites. Most have only 1 but all VLBA sites, for
example, have 2. This can be overridden for a schedule using the NDRIVES parameter
in the tape initialization information. Note that, even with Mark5A disks, this may
need to be set to 2 to allow 512 Mbps recording, which requires two heads or two
drives to give 64 tracks. NDRIVES should be the maximum number of drives at the
station. If less are in service, the tape initialization input, NDRIVES can be used to
specify the smaller number. For S2 sites, NDRIVES should be the number of individual
recorders.
-
NHEADS:
- Gives the number of recording head blocks on each VLBA or MKIV drive. This will be useful
mainly for MKIV (and VLBA4) which will at some point have 2.
-
DISK:
- Used to indicate that a disk based recording system is available at the station. Which system to
use depends on the value of the MEDIA parameter in the tape initialization information. For VLBA
systems, commands for both RECORDER and DISK can be included in the control file. Valid
arguments to DISK for now are restricted to MARK5A, MARK5B, LBADR and NONE (the
default).
-
MEDIADEF:
- Gives the default recording system to use. It can be overridden by MEDIA in the TAPEINI
section. The options are TAPE and DISK. This is meant to facilitate VLBA operations during the
transition from tape to disk.
Horizon:
-
HOR_AZ:
-
Up
to
200
azimuths
at
which
horizon
elevations
are
given
in
HOR_EL.
-
HOR_EL:
-
Up
to
200
elevations
for
the
horizon
at
the
azimuths
specified
by
HOR_AZ.
SCHED’s
down,
rise,
and
set
notes
will
take
these
horizons
into
account.
They
will
also
be
used
in
the
optimization
mode.
Mount details and performance:
-
MOUNT:
-
The
type
of
mount.
SCHED uses
this,
along
with
the
axis
limits
and
rates,
to
calculate
slew
times.
The
understood
options
are
ALTAZ,
EQUAT,
XYEW
and
XYNS.
Note
that
XYNS
is
for
an
XY
axis
system
with
the
fixed
axis
in
the
north-south
direction
(for
example,
Fairbanks).
XYEW
is
for
the
other
orientation
(for
example,
Hobart).
-
AXISTYPE:
-
The
axis
type
as
recorded
in
the
VLBA
correlator
data
base.
There
are
different
keywords
here
than
for
MOUNT.
Some
day
this
should
be
cleaned
up.
Can
be
put
in
the
locations
catalog.
Will
go
to
the
VEX
file.
-
AXISOFF:
-
The
axis
offset
in
meters.
Can
be
put
in
the
locations
catalog.
Will
go
to
the
VEX
file
for
correlation.
-
AX1LIM:
-
The
slew
limits
for
the
first
axis
which
is
usually
azimuth,
hour
angle
or
X.
The
units
are
degrees
for
azimuth
or
X
and
hours
for
equatatorial
mounts.
There
are
up
to
3
pairs
of
numbers
giving
the
lower
and
upper
limits
for
3
different
parts
of
the
sky.
This
is
required
to
describe
the
limits
for
the
140’
at
Green
Bank
and
for
XY
antennas
such
as
Hobart.
Only
the
first
set
will
be
used
for
altaz
antennas.
For
altaz
antennas,
the
zero
for
azimuth
is
to
the
north
and
positive
is
clockwise
looking
down
on
the
antenna.
For
XY
antennas,
positive
is
to
the
north
or
east.
-
AX2LIM:
-
The
slew
limits
for
the
second
axis
which
is
usually
elevation,
declination,
or
Y.
The
units
are
degrees
in
all
cases.
There
are
3
pairs
of
numbers
which
define
the
three
parts
of
the
sky
over
which
the
3
pairs
of
AX1LIMs
apply.
The
ranges
for
altaz
antennas
should
not
overlap,
although
they
can
touch.
For
XY
antennas,
overlaps
are
ok.
-
AX1RATE:
-
The
slew
rate
for
the
first
axis
in
degrees
per
minute
for
all
mount
types.
-
AX2RATE:
-
The
slew
rate
for
the
second
axis
in
degrees
per
minute.
-
AX1ACC:
-
The
acceleration
for
the
first
axis
in
degrees
per
second
squared
for
all
mount
types.
If
one
value
is
given,
it
is
assumed
to
apply
to
both
acceleration
and
deceleration.
If
two
values
are
given,
the
first
is
for
acceleration
and
the
second
for
deceleration
(although
for
the
calculations,
they
are
interchangeable).
-
AX2ACC:
-
The
acceleration
for
the
second
axis
in
degrees
per
second
squared.
If
one
value
is
given,
it
is
assumed
to
apply
to
both
acceleration
and
deceleration.
Scan timing information:
-
TSETTLE:
-
The
time
in
seconds
(or
mm:ss
etc)
to
add
to
the
slew
time
for
dwell
time
scheduling
to
determine
when
the
antenna
is
ready
to
observe.
This
will
include
any
computer
overhead,
and
time
to
make
calibration
observations.
Acceleration
and
deceleration
will
be
calculated
explicitly
if
the
above
acceleration
parameters
are
provided
in
the
station
catalog.
-
MINSETUP:
-
The
minimum
interval
between
scans
when
using
dwell
time
scheduling.
If
the
slew
time
plus
the
settling
time
drops
below
MINSETUP,
MINSETUP
will
be
used
as
the
interval
between
scans.
This
is
required
because
some
antennas
have
a
minimum
scan
setup
time
but
the
actions
that
take
that
time
can
overlap
with
the
slew.
When
the
slew
is
long,
the
extra
time
does
not
need
to
be
added.
-
TSCAL:
-
Lets
SCHED know
when
the
station
measures
system
temperatures.
Arguments
are
text
of
4
characters.
The
viable
options
so
far
are
“gap”
and
“cont”
that
indicate
the
system
temperature
measurements,
or
at
least
cal
measurements,
are
done
in
the
gap
between
scans
or
continuously
during
observing.
The
VLBA
uses
an
80Hz
cal
switch
and
measures
cal-on
and
cal-off
powers
from
which,
using
a
known
cal
temperature,
the
system
temperature
can
be
derived.
Typical
field
system
controlled
stations
fire
the
cal
once
at
the
start
of
a
scan
and
measure
the
on
and
off
power.
SCHED
will
warn
if
there
is
inadequate
time
to
do
this
if
TSCAL=GAP,
but
not
when
TSCAL=CONT.
This
facility
is
still
not
fully
installed
as
of
Nov.
5,
2008.
-
MAXSRCHR:
-
The
maximum
number
of
sources
per
hour.
This
is
originally
intended
to
enable
enforcement
of
the
limit
in
the
number
of
slews
per
hour
on
the
Mark1
telescope
at
Jodrell.
They
are
very
worried
about
fatigue
and
will
refuse
to
run
fast
switching
schedules.
The
default
is
1.E6
which
should
be
more
than
anyone
would
try
to
schedule.
-
TLEVSET:
-
This
is
a
time
to
be
added
to
the
slew
calculation
to
allow
for
the
set-and-remember
power
level
adjustments
that
happen
on
the
VLBA
(RDBE)
or
VLA
the
first
time
a
particular
setup
is
seen.
Like
MINSETUP,
the
time
can
overlap
with
slews
so
functionally,
this
parameter
acts
exactly
like
MINSETUP
but
only
for
the
first
scan
with
a
particular
setup.
The
VLBA
needs
15
seconds.
The
VLA
needs
60
seconds.
As
of
Nov.
2012,
the
VLA
actually
needs
this
every
time
there
is
a
slight
frequency
change
(like
new
Doppler
shift),
but
we
will
try
to
get
that
changed
to
be
only
for
more
major
changes.
Note
that,
if
the
first
scan
with
a
setup
is
non-recording,
non-pointing,
and
non-phasing,
the
scan
itself
will
be
accepted
as
the
level
setting
(DUMMY
on
the
VLA)
scan.
This
allows
for
explicit
insertion
of
DUMMY
scans.
Below is a sample entry from the RDBE based version of the standard station catalog. The full catalog
a can be examined here for the version that uses MARK5A at the VLBA and here for the RDBE based
version.
STATION=VLBA_MK STCODE=Mk CONTROL=VLBA
DBNAME = MK-VLBA
MOUNT=ALTAZ AX1LIM=-90,450 AX2LIM=2.25,90 AX1RATE=86.8 AX2RATE=28.3
AX1ACC=0.75 AX2ACC=0.25
TSETTLE=6 TLEVSET=5 MINSETUP=5 DAR=RDBE NBBC=16
DISK=MARK5C MEDIADEF=DISK TSCAL=CONT
! MK From 150 K Ts line by Beasley and Medcalf Aug 1992.
HOR_AZ = 0, 5, 10, 15, 20,120,125,130,135,140,145,150,155,160,
165,170,175,185,190,195,200,205,210,215,220,255,260,270,
275,280,285,290,295,300,305,310,315,320,325,330,335,340,
345,350,355,360
HOR_EL = 5, 4, 3, 3, 2, 2, 4, 5, 5, 4, 4, 6, 8, 8,
11, 12, 13, 13, 11, 11, 9, 7, 5, 3, 2, 2, 3, 3,
5, 6, 8, 10, 12, 14, 12, 11, 9, 10, 11, 10, 12, 14,
12, 9, 7, 5
/