AIPS HELP file for VLACALIB in 31DEC24
As of Mon Oct 14 8:19:59 2024
VLACALIB: Procedure to run CALIB and LISTR for VLA calibration.
INPUTS
Use RUN VLAPROCS first!!!
INNAME UV file name (name)
INCLASS UV file name (class)
INSEQ 0.0 9999.0 UV file name (seq. #)
INDISK 0.0 9.0 UV file disk drive #
Data selection (multisource):
CALSOUR Calibrator sources
CALCODE Calibrator code '*'=>all cal.
QUAL -10.0 Calibrator qualifier -1=>all
TIMERANG Time range to use.
ANTENNAS Antennas to solve for. 0=all
UVRANGE Range of uv distance for full
weight, 0 outside.
REFANT Reference antenna
DOCALIB -1.0 2.0 If >0 calibrate data
= 2 calibrate weights
GAINUSE CL table to apply, 0=> latest
FLAGVER Flagtable version 0=> highest
DOBAND -1.0 10.0 If >0 apply bandpass cal.
Method used depends on value
of DOBAND (see HELP file).
BPVER Bandpass table version
SNVER SN table to write, 0=> create
new table
MINAMPER Min. amplitude closure error
MINPHSER Min. phase closure error
FREQID Unique frequency code
DOPRINT >0 Print messages to a file
or to the printer.
OUTPRINT Printer disk file to save
HELP SECTION
VLACALIB
Procedure: This procedure is designed to simplify determining
antenna based calibration for calibrating VLA data from
external calibrator sources. It accepts a subset of the
input adverbs for CALIB and uses the default values for
the rest. After running CALIB the solution table (SN)
produced is printed by LISTR, if DOPRINT>=0. Note that
if DOPRINT>=0 then depending on your window size you may
have to press return a second time for the procedure to
continue.
PRIMARY FLUX CALIBRATOR MODELS will be automatically
downloaded and used if: 1) CALSOUR is set to ONLY the
flux calibrator; 2) UVRANGE and ANTENNAS are 0; and
3) a model exists (seem CALDIR for a list of current
models).
Before attempting to use VLACALIB the RUN file
VLAPROCS must be run to define the adverbs used and to
read in the procedure. This is done by:
>RUN VLAPROCS
and only needs be done once.
Adverbs:
INNAME.....Input UV file name (name). Standard defaults.
INCLASS....Input UV file name (class). Standard defaults.
INSEQ......Input UV file name (seq. #). 0 -> highest.
INDISK.....Disk drive # of input UV file. 0 -> any.
CALSOUR....List of sources for which calibration constants
are to be determined, i.e. the calibrator sources
All ' ' = all sources; a "-" before a source name.
means all except ANY source named.
Note: solutions for multiple sources can only be
made if the sources are point sources at their
assumed phase center and with the flux densities
given in the source (SU) table.
For primary flux calibrator models to be used
CALSOUR must be set to ONLY the that calibrator.
See EXPLAIN.
CALCODE....Calibrators may be selected on the basis of the
calibrator code:
' ' => any calibrator code selected
including non-calibrators.
'* ' => any non blank code (cal. only)
'-CAL' => blank codes only (no calibrators)
anything else = calibrator code to select.
NB: The CALCODE test is applied in addition to the
other tests, i.e. CALSOUR and QUAL, in the
selection of sources for which to determine
solutions.
QUAL.......Only sources with a source qualifier number in the
SU table matching QUAL will be used if QUAL is not
-1.
TIMERANG...Time range of the data to be used. In order:
Start day, hour, min. sec,
end day, hour, min. sec. Days relative to ref.
date.
ANTENNAS...A list of the antennas to have solutions
determined. If any number is negative then all
antennas listed are NOT to be used to determine
solutions and all others are. All 0 => use all.
For primary flux calibrator models to be used
this MUST be 0. See EXPLAIN.
UVRANGE....The range of uv distance from the origin in
kilowavelengths over which the data will have
full weight; outside of this annulus in the uv
plane the data will be given a weight of 0.
For primary flux calibrator models to be used
this MUST be 0. See EXPLAIN.
REFANT.....The desired reference antenna for phases.
DOCALIB....If true (>0), calibrate the data using information in the
specified Cal (CL) table for multi-source or SN table for
single-source data. If > 1.5, also calibrate the weights
(new for VLA, normal for VLBI). Applied before
determining new solutions. The calibration data in
the CL table version specified by GAINUSE will be used.
GAINUSE....version number of the CL table to apply to the data.
0 => highest.
FLAGVER....specifies the version of the flagging table to be applied.
0 => highest; <0 => no flagging to be applied.
SNVER......The version of the SN table to write the solutions
to. If =0, a new SN table is generated. Prior
to 15OCT95, SNVER was fixed =1 so that solutions
were always written to SN #1. If 0 is selected and
VLACALIB is run multiple times, be careful to
remove those SN tables which contain unacceptable
solutions before applying calibration (vis CLCAL..)
MINAMPER...If > 0 then the values of any amplitude closure errors
whose abs. percentage value exceeds MINAMPER will be
printed. Any whose average over all baselines exceeds
MINAMPER/10 will be printed (1 per cal time).
MINPHSER...If >0 then the values of any phase closure errors whose
value exceeds MINPHSER degrees will be printed. Any whose
average over all baselines exceeds MINPHSER/10 will be
printed (1 per cal time).
FREQID.....Frequency selection. Defaults to 1. This is what
is required in most continuum cases.
DOPRINT....If > 0 print inputs to VLACALIB and performs a LISTR (see
EXPLAIN VLACALIB) to either the printer or to a
file specified in OUTPRINT. Note that if this value is
positive you may have to hit return for the procedure
to continue running after it does the INPUTS command.
OUTPRINT...Disk file name in which to save output. ' ' => print
to printer - When OUTPRINT is not blank, outputs are
printed to a file. Multiple uses of the same
are concatenated.
EXPLAIN SECTION
VLACALIB: Procedure to run CALIB with fewer inputs and
possibly print the results with PRTMSG and LISTR.
Documenter: Amy Mioduszewski
Related Programs: CALIB, LISTR, PRTMSG, CALRD
STEPS in VLACALIB:
Note that if DOPRINT<=0 then only step 2 is performed.
1. If DOPRINT>0 then
a. clear AIPS messages using CLRMSG
b. put inputs of VLACALIB into AIPS messages
(using INPUT VLACALIB)
c. clear CALIB messages using CLRMSG
2. Load flux calibrator models, under certain conditions.
See below.
3. RUN CALIB, with VLACALIB inputs and:
APARM 4, 0, 0, 0, 0, 2;
SOLMODE 'A&P';
CPARM 0, 0, MINAMPER/10, MINPHSER/10, 1, 0
4. If DOPRINT>0 then print AIPS and CALIB messages
using PRTMSG to the selected printer or to the file
stated in OUTPRINT.
5. If DOPRINT>0 then run LISTR with VLACALIB inputs and:
OPTYPE 'gain'
INEXT 'SN'
BIF 1; EIF 2
STOKES 'HALF'
DPARM 5, 1, 0
If you would like to run with DOPRINT=1 but would still like to
keep your AIPS and CALIB messages. Start AIPS in another window
to create another POPS number (when you run AIPS and see an
"AIPS 2" or "IMAGR2"; 2 is the POPS number) and run VLACALIB in
that window. Only the messages from that POPS number will be
deleted.
PRIMARY FLUX CALIBRATOR MODELS
Most of the primary flux calibrators (3C286, 3C48, 3C138 and 3C147),
have models of there structure. These should be used if they exist
(use verb CALDIR for a list of models), to this end calibrator models
have been added to VLACALIB. VLACALIB will automatically load a
calibrator model (if it exists) and use it if:
1) CALSOUR is set to ONLY the flux calibrator
2) ANTENNAS is 0
3) UVRANGE is 0
If you do not want to use calibrator models the easiest way to turn
this off is to set UVRANGE to something large (e.g. UVRANGE=0 100000)
if you don't need to limit it for the calibration.
The models are named Name_Band.Model.* e.g., 3C286_X.MODEL.1 and will
be loaded to the INDISK.