AIPS HELP file for TI2HA in 31DEC24
As of Fri Jul 26 18:41:43 2024
TI2HA: Task to change times to hour angles
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 name
QUAL -10.0 Calibrator qualifier -1=>all
CALCODE Calibrator code ' '=>all
STOKES Stokes of output
TIMERANG Time range to use
SELBAND Bandwidth to select (kHz)
SELFREQ Frequency to select (MHz)
FREQID Freq. ID to select.
SUBARRAY 0.0 1000.0 Sub-array, 0=>all
BIF Low IF number to do
EIF Highest IF number to do
BCHAN 0.0 First channel included
ECHAN 0.0 last channel included
DOCALIB -1.0 101.0 > 0 calibrate data & weights
> 99 do NOT calibrate weights
GAINUSE CL (or SN) table to apply
DOPOL -1.0 10.0 If >0.5 correct polarization.
PDVER PD table to apply (DOPOL>0)
BLVER BL table to apply.
FLAGVER Flag table version
DOBAND -1.0 10.0 If >0.5 apply bandpass cal.
Method used depends on value
of DOBAND (see HELP file).
BPVER Bandpass table version
SMOOTH Smoothing function. See
HELP SMOOTH for details.
OUTNAME Output UV file name (name)
OUTCLASS Output UV file name (class)
OUTSEQ -1.0 9999.0 Output UV file name (seq. #)
OUTDISK 0.0 9.0 Output UV file disk unit #.
DOARRAY -1.0 1.0 > 0 => subtract 5 days from
times for subarray number
FQCENTER >= 0 -> center frequency axis
REFANT > 0 => all hour angles wrt
REFANT, else IANT1 each vis
BADDISK Disks to avoid for scratch
HELP SECTION
TI2HA
Task: This task will copy an entire data set replacing the IAT time
with the hour angle (biased by one day to avoid negatives).
The hour angle is for the lower numbered antenna IN EACH DATA
SAMPLE. Thus, the data will not be exactly in "time" order on
output and should be sorted. For VLA data, you may specify an
reference antenna and then all hour angles will be wrt that
antenna and so the output data set should be in time order.
This may not be a good idea for VLB data sets.
If the data are already in hour angle form, they will simply be
copied.
WARNING: data from the EVLA (WIDAR correlator) will have hour
angles wrt Greenwich rather than the center of the VLA. You
must not combine pre-Widar data with Widar data after TI2HA.
The output should be used for self-calibration with great care,
since times from multiple days can be confused. The task works
on single-source data sets only because of the importance of
correct times to multi-source data handling. INNAME may point
to a multi-source data set, so long as only one source is
selected for the output. This task is envisioned as allowing
users to average data taken at the same times and with the same
arrays over multiple days. The averaging can then be done
(after a UVSRT or MSORT) with UBAVG, UVAVG, or AVER.
The output of TI2HA is normally concatenated and averaged with
data from identical subarrays taken on other days compiling
deep integrations. There is a RUN file RUN STUFFER which
compiles a procedure STUFFR to assist with this process
(stuffing multiple data sets into a smaller combined data set).
If you insist on doing it yourself:
When combining various data sets, run DBCON before running
TI2HA while using DOARRAY=-1. Then run TI2HA with DOARRAY=1.
If you run TI2HA on the separate data sets, then DBCON will use
the observation dates to adjust the times to be relative to the
one in the output header - which you probably do not want. To
stop this do on one of the uv files KEYWORD='DATE-OBS'; GETHEAD
and then do PUTHEAD on all of the others.
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.
SOURCES....Source to be copied. ' '=> all; if any starts with
a '-' then all except ANY source named.
QUAL.......Qualifier of source to be copied. -1 => all.
CALCODE....Calibrator code of sources to copied. ' '=> all.
STOKES.....Specifies which STOKES parameters are written in the
output data set: ' ' => 'FULL'
'I','Q','U','V', 'IV', 'IQU', 'IQUV'
'RR','LL', 'RL', 'LR', 'RRLL', 'RLLR', 'RLRL'
'VV','HH', 'VH', 'HV', 'VVHH', 'VHHV', 'VHVH'
'HALF', 'CROS', and 'FULL' have sensible interpretations
depending on the Stokes present in the data. The last in
each of the 3 rows above == 'FULL'. Note that many
combinations of polarizations in the input and values
above are not supported.
TIMERANG...Time range of the data to be copied. In order: Start day,
hour, min. sec, end day, hour, min. sec. Days relative to
ref. date.
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 result in an ambiguity. In that case, the task
will request that you use FREQID.
SUBARRAY...Sub-array number to copy. 0=>all.
BIF........First IF to include. 0 -> 1.
EIF........Last IF to include. 0 -> max.
BCHAN......First channel to copy. 0=>all.
ECHAN......Highest channel to copy. 0=>all higher than BCHAN
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. Also calibrate the weights unless
DOCALIB > 99 (use this for old non-physical weights).
GAINUSE....version number of the CL table to apply to multi-source
files or the SN table for single source files.
0 => highest.
DOPOL......If > 0 then correct data for instrumental polarization as
represented in the AN or PD table. This correction is
only useful if PCAL has been run or feed polarization
parameters have been otherwise obtained. See HELP DOPOL
for available correction modes: 1 is normal, 2 and 3 are
for VLBI. 1-3 use a PD table if available; 6, 7, 8 are
the same but use the AN (continuum solution) even if a PD
table is present.
PDVER......PD table to apply if PCAL was run with SPECTRAL true and
0 < DOPOL < 6. <= 0 => highest.
BLVER......Version number of the baseline based calibration (BL) table
to apply. <0 => apply no BL table, 0 => highest.
FLAGVER....specifies the version of the flagging table to be applied.
0 => highest numbered table.
<0 => no flagging to be applied.
DOBAND.....If true (>0) then correct the data for the shape of the
antenna bandpasses using the BP table specified by BPVER.
The correction has five modes:
(a) if DOBAND=1 all entries for an antenna in the table
are averaged together before correcting the data.
(b) if DOBAND=2 the entry nearest in time (including
solution weights) is used to correct the data.
(c) if DOBAND=3 the table entries are interpolated in
time (using solution weights) and the data are then
corrected.
(d) if DOBAND=4 the entry nearest in time (ignoring
solution weights) is used to correct the data.
(e) if DOBAND=5 the table entries are interpolated in
time (ignoring solution weights) and the data are then
corrected.
IMAGR uses DOBAND as the nearest integer; 0.1 is therefore
"false".
BPVER......Specifies the version of the BP table to be applied
0 => highest numbered table.
<0 => no bandpass correction to be applied.
SMOOTH.....Specifies the type of spectral smoothing to be applied to
a uv database . The default is not to apply any smoothing.
The elements of SMOOTH are as follows:
SMOOTH(1) = type of smoothing to apply: 0 => no smoothing
To smooth before applying bandpass calibration
1 => Hanning, 2 => Gaussian, 3 => Boxcar, 4 => Sinc
To smooth after applying bandpass calibration
5 => Hanning, 6 => Gaussian, 7 => Boxcar, 8 => Sinc
SMOOTH(2) = the "diameter" of the function, i.e. width
between first nulls of Hanning triangle and sinc
function, FWHM of Gaussian, width of Boxcar. Defaults
(if < 0.1) are 4, 2, 2 and 3 channels for SMOOTH(1) =
1 - 4 and 5 - 8, resp.
SMOOTH(3) = the diameter over which the convolving
function has value - in channels. Defaults: 1,3,1,4
times SMOOTH(2) used when input SMOOTH(3) < net
SMOOTH(2).
OUTNAME....Output UV file name (name). Standard defaults.
OUTCLASS...Output UV file name (class). Standard defaults.
OUTSEQ.....Output UV file name (seq. #). 0 => highest unique
OUTDISK....Disk drive # of output UV file. 0 => highest with
space for the file.
DOARRAY....Times are often altered by DBCON by adding
5*(subarray#-1). If DOARRAY>0 and the time is suitable,
this offset will be subtracted before the hour angle is
determined. If DOARRAY>0, the baseline code with each
sample will be changed to drop the subarray indicator if
the time is changed. Only one AN file will be copied if
DOARRAY>0.
FQCENTER...> 0 => Change frequency axis reference pixel to
Nchan / 2 + 1
else => do not change reference pixel
REFANT.....> 0 use this antenna number to compute all hour angles
= 0 use the lower numbered antenna of each visibility
pair to define the hour angle.
BADDISK....The disk numbers to avoid for scratch files (sorting
tables mostly).
EXPLAIN SECTION