AIPS HELP file for GETJY in 31DEC24
As of Wed Apr 24 1:14:11 2024
GETJY: Task to determine source flux densities.
INPUTS
INNAME Input UV file name (name)
INCLASS Input UV file name (class)
INSEQ 0.0 9999.0 Input UV file name (seq. #)
INDISK 0.0 9.0 Input UV file disk unit #
SOURCES Source list to find fluxes
SOUCODE Source "Cal codes"
CALSOUR Cal sources for calibration
QUAL -10.0 Source qualifier -1=>all
CALCODE Calibrator code ' '=>all
BIF 0.0 100.0 Lowest IF number 0=1
EIF 0.0 100.0 Highest IF number
TIMERANG Time range of solutions.
ANTENNAS Antennas to use
SUBARRAY 0.0 1000.0 Subarray, 0=>all
SELBAND Bandwidth to select (kHz)
SELFREQ Frequency to select (MHz)
FREQID Freq. ID to select.
SNVER Input SN table, 0=>all.
HELP SECTION
GETJY
Task: Determines flux densities from CALIB solution (SN) tables,
enters the results in the source (SU) table, and corrects the
amplitudes of the solutions in the SN tables. There is a limit
of 500 sources including the calibration sources. Before
running GETJY:
1) SETJY should be run to insert the flux densities of the
primary flux density calibrators into the SU table.
2) SETJY should also be run to set some flux (1.0 will do) for
any secondary calibrator for which you intend to use a model.
3) CALIB should be run on all primary and secondary flux
density calibrators. Separate runs may be needed for
different sources if UVRANGE and/or ANTENNAS need to be
different or if some sources have models.
After running GETJY:
4) If you have numerous IFs (spectral windows), run SOUSP to
see if the solutions are reasonable and perhaps to
substitute the fitted flux and spectral index for the
individual, per-IF fluxes.
5) Run CLCAL to apply the SN tables to a specified CL table.
NOTE: GETJY may be run multiple times without adversely affecting
either the SN or SU tables. Some users have models for sources other
than those provided with AIPS. To use such a model, it is recommended
that you first run SETJY to set some total flux in the SU table. Then
the model will be scaled to that flux and GETJY may be used to adjust
that scale after CALIB. If you do not set a non-zero flux for such
calibrators, CALIB will use the flux contained in the model but GETJY
will assume 1.0 and the result after GETJY will be erroneous. You can
use SETJY after CALIB to put the total flux of your model as reported
in CALIB into the SU table before GETJY. That should work.
The averaging methods were changed on October 12, 2009:
(1) First the antenna gains for the calibration sources are averaged
separately for each antenna, polarization, and IF. The averaging
is now done by robust methods in which outliers do not contribute
to the average or rms. The number of gain samples contributing to
these averages (summed over antenna, polarization, and IF) is
reported along with the total number of calibration source
samples. Any samples more than six times the rms from the mean
are counted over antenna, polarization, and IF and are then
reported.
(2) Then, one source at a time, the antenna gains are averaged
robustly separately for each antenna, polarization, and IF. The
total number of such samples, the number contributing to the
averages, and the number more than six rms away from the mean are
counted over all antennas, polarizations, and IFs.
(3) The ratio of the source gain to the average calibrator gain in
each antenna and polarization is averaged separately for each IF
using robust methods. The number of samples possible in each
average, the number used, and the number more than six rms away
from the mean are counted over all IFs. The apparent flux in each
IF is reported along with the formal error using both the robust
rms and an rms computed over all samples. The formal error is the
rms of the average over antennas and polarizations divided by the
square root of the number of samples used in the robust mean minus
one.
(4) Following all source fluxes, the counts in the second and third
averages are reported separately for each source.
Adverbs:
INNAME.....Input UV file name (name). Standard defaults.
Multisource files only.
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.
SOURCES....List of sources whose flux densities are to be
determined. '*' or '' => all; a "-" before a
source name means all except ANY source named.
SOUCODE....Sources may be selected on the basis of the
calibrator code given in the SU table.
' ' => any calibrator code selected
'* ' => any non blank code (cal. only)
'-CAL' => blank codes only (no calibrators)
anything else = calibrator code to select.
NB: The SOUCODE test is applied in addition to the
other tests, i.e. SOURCES and QUAL, in the
selection of sources to process.
CALSOUR....List of calibrators to use to determine source
flux densities. The flux densities of these
sources should have been entered into the SU table
using SETJY before running CALIB. '*' or '' = all;
a "-" before a calibrator name means all except
ANY calibrator named.
QUAL.......Only sources with a source qualifier number in the
SU table matching QUAL will be used if QUAL is not
-1. QUAL affects the selection of both the list of
sources and the list of calibrators.
CALCODE....Calibrators may be selected on the basis of the
calibrator code given in the SU table.
' ' => any calibrator code selected
'* ' => 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 calibrators.
CALCODE affects only the selection of calibrators.
BIF........Lowest IF number to process, 0=>1.
EIF........Highest IF number to process, 0=>all.
TIMERANG...Time range of the data to be considered. In order:
Start day, hour, min. sec,
end day, hour, min. sec. Days relative to ref.
date. TIMERANG is only used in the determination
of the source flux densities. Solutions at all
times are corrected by the determined flux
densities.
SUBARRAY...Subarray number to use. 0=>all.
Only data in subarray SUBARRAY are used to
determine flux densities and only solutions in this
subarray are corrected.
ANTENNAS...A list of the antennas to use. If any number
is negative then all antennas listed are NOT
desired and all others are. All 0 => use all.
ANTENNAS is only used to determine the source flux
densities; solutions for all antennas are
corrected.
SELBAND....Bandwidth of data to be selected. If more than
one IF is present SELBAND is the width of the
first IF required. Units = kHz. For data which
contain multiple bandwidths/frequencies the task
will insist that some form of selection be made
by frequency or bandwidth.
SELFREQ....Frequency of data to be selected. If more than
one IF is present SELFREQ is the frequency of the
first IF required. Units = MHz.
FREQID.....Frequency identifier to select (you may determine
which is applicable from the OPTYPE='SCAN' listing
produced by LISTR). If either SELBAND or SELFREQ
are set, their values override that of FREQID.
However, setting SELBAND and SELFREQ may
occasionally result in an ambiguity. In that
case, the task will request that you use FREQID.
SNVER......Selected SN table(s). If SNVER > 0 then only SN
version SNVER is used. If SNVER <= 0 then all SN
tables are selected.
EXPLAIN SECTION