AIPS HELP file for TYSMO in 31DEC24
As of Tue Apr 23 9:47:08 2024
TYSMO: Task which smooths/filters system temperature tables
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 ' '=>all.
DOBTWEEN -1.0 1.0 > 0 -> smooth all sources
together; else separate them
SELBAND Bandwidth to select (kHz)
SELFREQ Frequency to select (MHz)
FREQID Freq. ID to select, 0=>all
BIF 0.0 100.0 Lowest IF number 0=>all
EIF 0.0 100.0 Highest IF number 0=>all
TIMERANG Time range to use.
ANTENNAS Antennas to correct.
SUBARRAY 0.0 9999.0 Subarray; 0 => all.
FLAGVER -1.0 Apply flag table first?
0 => highest, -1 => no
INEXT 'TY' or 'SY' or choose
INVERS Input ?Y table; 0=>highest
OUTVERS Output ?Y table; 0=>new
APARM Range of allowed T's or P's
DOSCALE -1.0 1.0 > 0 => MWF values are
normalized by their median
CPARM Clip wrt median filter
SAMPTYPE Smoothing function
BPARM Smoothing parameters
CUTOFF 0.0 Cutoff for functional forms
DOBLANK Blanked value interpolation
BADDISK 0.0 9999.0 Disks to avoid for scratch
HELP SECTION
TYSMO
Task: This task edits and smooths a TY or SY table. For TY tables,
the antenna and system temperatures are clipped to be in
reasonable ranges. For SY tables, the Pdif (noise tube on -
noise tube off) and Psum (Pon+Poff) columns and their ratio
(Psum/Pdif/2*Tcal = Tsys) are clipped to be in reasonable
ranges. Then they are time smoothed. Blanked values will be
interpolated or not under control of DOBLANK. In TY tables.
for some telescopes, Tsys and Tant are what they are labled to
be. For the VLA, Tsys is the nominal sensitivity and Tant is
some form of system temperature. The SY table is an EVLA
concept and contains Pdif, Psum, and PostGain columns. At the
synchronous detector, the measured power is Pon with the noise
tube on and Poff with the noise tube off and PostGain is any
gain that follows this detector. Then Pdif = PostGain * (Pon -
Poff) and Psum = PostGain * (Pon + poff). The ratio, Psum/Pdif
is twice the Tsys divided by the noise tube Tcal.
Note that TYAPL with SY tables requires valid values for Pdif,
Psum, and the post-detector gains. If you are replacing flagged
SY table values with smoothed values you should do this for all
three data types whether your data are 3-bit or 8-bit.
DOBTWEEN controls whether values from different sources are
smoothed separately or together. Unless all sources have
similar strength and similar spill-over and the like, use
DOBTWEEN <= 0. This is especially important when the observing
run includes observations of the Sun. For solar data, you
should also note that not all antennas have "solar cals". Do
not use Psys in smoothing and clipping since those antennas will
be completely flagged due to the absence of a proper cal.
For each IF, TYSMO reports the number of times that Psum <=
Pdif as "improper SY records. Then it uses 3 columns to report
the number of samples flagged by the clip set by APARM, the
number of samples flagged after the median-window filer set by
CPARM, and the number of samples already flagged in the output
of the MWF. The last could arise is a significant number of
consecutive samples have been clipped or flagged in some way
prior to the MWF. There are separate lines for Pdif, Psum,
Psys, and Pgain. Finally the number of SY table records changed
by this flagging is reported.
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....list of sources to process: '*' = all;
a "-" before a source name means all except ANY source
named.
DOBTWEEN...> 0 => smooth all TY/SY values regardless of source.
<= 0 => smooth only TY/SY values from the same source.
Well-separated calibrators may have different spill-over
and background temperatures, so one would not want to
smooth them together. This can be achieved via doing one
source at a time, but DOBTWEEN allows one to do all
sources at once - at least if the choice is a simple
one. If you do Pgain, you really must set DOBTWEEN = 0.
FREQID.....Frequency identifier to select (you may determine which
is applicable from the OPTYPE='SCAN' listing produced by
LISTR).
BIF........First IF to process. 0=>all.
EIF........Highest IF to process. 0=>all higher than BIF
TIMERANG...Time range of the data to be used. In order:
Start day, hour, min. sec, end day, hour, min. sec.
Days relative to reference date.
ANTENNAS...A list of the antennas to be modified. If any number is
negative then all antennas listed are NOT to be modified.
All 0 => use all.
SUBARRAY...The subarray to modify. 0 -> all.
FLAGVER....< 0 => do NOT apply a flag table to the SY/TY table
0 => apply the highest numbered FG table to the SY/TY
table INVERS as it is copied to OUTVERS
> 0 => apply FG version FLAGVER to the SY/TY table INVERS
as is copied to OUTVERS
INEXT......'SY' or 'TY' else select whichever is present and die if
both are present.
INVERS.....input version number of the TY/SY table to smooth.
0 => Highest.
OUTVERS....output version of TY/SY table to write.
0 => create new table (recommended)
APARM......Data can first be clipped on the actual values:
(1) => min Tsys or Pdif 0 => zero
(2) => min Tant or Psum 0 => zero
(3) => min Psum/Pdif/2*Tcal = Tsys 0 => zero
(4) => min Pgain 0 => zero
(6) => max Tsys or Pdif 0 => very large
(7) => max Tant or Psum 0 => very large
(8) => max Psum/Pdif/2*Tcal = Tsys 0 => very large
(9) => max Pgain 0 => very large
Note - you will need very differnt values for clipping
solar data and regular-source data. Use SOURCES to limit
each run on the SY table to the Sun or to normal
sources.
DOSCALE....> 0 => the data in each scan is normalized by the median
of those data so that CPARM(6) - CPARM(9) are
relative numbers
<= 0 => CPARM(6) - CPARM(9) are absolute numbers in the
appropriate data type.
CPARM......Data can then be clipped by comparison with a median
window filter. The width of the Median window is
specified in CPARM(1, 2, 3, or 4). The maximum allowed
deviation is given in CPARM(6, 7, 8, or 9).
0 => all values are OK.
(1) => smoothing time for Tsys or Pdif (minutes),
(2) => smoothing time for Tant or Psum (minutes),
(3) => smoothing time for Psum/Pdif/2*Tcal = Tsys (min)
(4) => smoothing time for Pgain
(6) => max deviation for Tsys or Pdif
(7) => max deviation for Tant or Psum
(8) => max deviation for Psum/Pdif/2*Tcal = Tsys
(9) => max deviation for Pgain
SAMPTYPE...The type of smoothing to follow clipping (if any)
'BOX ' = boxcar smoothing (default)
'MWF ' = Median window filter
'GAUS' = Gaussian
'EXP ' = Exponential
'LINE' = Linear (1 - abs(t-t0)/sigma)
'2PT ' = Two-point
'2PTH' = Two-point + "Hanning"
BPARM......Parameters for smoothing function: note that we cannot
smooth Tsys in SY tables since that is the ratio of the
two measured quantities.
Function support full-width width in minutes
(1) => support time for Tsys or Pdif, (0 -> skip)
(2) => support time for Tant or Psum, (0 -> skip)
(4) => support time for Pgain, (0 -> skip)
Added parameter (FWHM) for GAUS, EXP, LINE in minutes
(6) => smoothing FWHM time for Tsys or Pdif,
(7) => smoothing FWHM time for Tant or Psum,
(9) => smoothing FWHM time for Pgain,
In all cases, the substitution for blanked and good
solutions is governed by DOBLANK (see below)
CUTOFF.....Cutoff for GAUS, EXP, LINE. The sum of the weighting
function in the support region must exceed CUTOFF for the
smoothed value to be regarded as valid. Be careful, a
value of 1.5 means that the sample itself must be good
and the sum over other good samples in the support range
must exceed 0.5. < 1.e-6 => 1.e-6.
DOBLANK....Blanked value interpolation:
> 0: replace previously blanked values with smoothed
values, leave previously good values unchanged.
= 0: replace previously blanked and previously good
values with smoothed values.
< 0: replace previously good values with smoothed values,
leave previously blanked values blanked.
BADDISK....A list of disks on which scratch files are not to be
placed. This will not affect the output file.
EXPLAIN SECTION