AIPS HELP file for FRPLT in 31DEC22
As of Tue Sep 26 17:51:42 2023
FRPLT: Task to plot fringe rate spectra.
USERID User number - ignored
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
QUAL -10.0 Source qualifier -1=>all
CALCODE Source code ' '=>all
SELBAND Bandwidth to select (kHz)
SELFREQ Frequency to select (MHz)
FREQID Freq. ID to select.
UVRANGE UV range to be plotted
TIMERANG Time range to be plotted
STOKES Stokes type to select.
BIF 0.0 100.0 Lowest IF number 0=>all
EIF 0.0 100.0 Highest IF number 0=>all
BCHAN 0.0 2048.0 Lowest channel number 0=>all
ECHAN 0.0 2048.0 Highest channel number 0=>all
SUBARRAY 0.0 1000.0 Subarray, 0=>all
ANTENNAS Antennas to select
BASELINE Baselines with ANTENNAS
DOACOR -1.0 1.0 Include autocorrelations?
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 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 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.
SHIFT Position shift:
RA, Dec (arcsec)
0 => no shift
APARM Control information:
1: pre-average interval (sec)
= 0 => 2 sec
2: = 0 => self-scale
> 0 => fixed scale
3: min. amplitude
4: max. amplitude
5: min. phase (degrees)
6: max. phase
7: plot type
= 0 fringe rate spectrum
= 1 visibility vs time
8: zero padding for FFT
0, 1 => no padding
2 => N zeroes
3 => 2N zeroes etc.
9 > 0 => plot several IF's
together as though one
long spectrum (see HELP)
10 = 1 => phase only,
= 2 => ampl only
CODETYPE 'A&P ', 'AMP ', 'PHAS',
'R&I ', 'REAL', 'IMAG'
other => 'A&P '
POLPLOT Option to display various
combinations of polzns to
plot: see help for allowed
values; other => this option
is not used.
SOLINT If SOLINT > 0 then it enables
the user to make multiple
plots per pass of FRPLT.
It defines the time interval
for each individual plot.
Task will start at TIMERANG
and make a plot for every
SOLINT minutes. If SOLINT
= -1 will do the same but
will step by scans if NX
table is present.
NPLOTS 0.0 9.0 Number of plots per page
BPARM More control information:
1: If = 1 divide by 'channel
0' before plotting data.
0 => do not divide.
2: Start chn. of 'channel 0'
(0 => determined by FRPLT)
3: Stop chn. of 'channel 0'
(0 => determined by FRPLT)
4: ignore spectrum when ampl.
channel 0 < BPARM(4) Jy
5: Xmin if APARM(2) > 0
6; Xmax if APARM(2) > 0
10: =1 => don't write header
info when writing to outfile
useful for appending several
spectra into a single outfile
[see EXPLAIN FRPLT]
OUTTEXT Filename in which to write
spectrum. Default = ' ' =
do not write spectrum.
LTYPE -410.0 410.0 Type of labeling: 1 border,
2 no ticks, 3 - 6 standard,
7 - 10 only tick labels
<0 -> no date/time
FACTOR Scale plus signs by FACTOR
BADDISK 0.0 9999.0 Disks to avoid for scratch
DOTV -1.0 1.0 > 0 Do plot on the TV, else
make a plot file
GRCHAN 0.0 8.0 Graphics channel 0 => 1.
Use: Plots fringe-rate spectra over specified periods of time either
on the TV or in a plot file. The data to be plotted can be
selected using a variety of criteria e.g. UVRANGE, TIMERANG,
and/or by selecting data from various baselines using the
ANTENNAS and BASELINE adverbs. Calibration and flagging can be
applied to the data before the spectrum is generated. The
program will work with single-source data files, or
multi-source files. Multiple plots may be placed on a page
using the adverb NPLOTS. Multiple IFs and/or polarizations may
be plotted as one long spectrum (correctly separated and
labeled). The data can be averaged over a range of frequency
channels within a given IF before the fringe rate spectrum is
generated. The FFT can be padded optionally with zeroes and is
computed with uniform weighting. The data can also be
pre-averaged over time.
The fringe frequency range of the plot is controlled be the
time range specified for the time interval. The start time may
be adjusted for the actual start time of the data (SOLINT > 0)
but the end time will be the lesser of the start time + SOLINT
and the specified end time. When time samples in the interval
do not contain data samples, the data are interpolated. It is
probably not good to have the end time well past the actual end
of the selected data. This invents data - use APARM(8) to have
finer sampling via zero-padding of the FFT. Note too that
SOLINT=-1 sets the time range to that time range in the index
(NX) table and is not adjusted for the actual times of the data
samples within the scan. The X-axis range is, by default, set
by the number of samples in the time interval and will change
slightly if the number of times included changes. You may
force a fixed X-axis range if desired (primarily to compare two
or more plots).
USERID.....Input file user number. Ignored
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 list. If the data is a multi-source file, FRPLT
will form the spectrum for the first source specified. If
the data is a single source file no source name need be
QUAL.......Only sources with a source qualifier number in the SU
table matching QUAL will be used if QUAL is not -1.
CALCODE....Sources may be selected on the basis of the source code:
' ' => any source code selected
'* ' => any non blank code
'-CAL' => blank codes only (no calibrators)
anything else = source code to select.
NB: The CALCODE test is applied in addition to the other
tests, i.e. SOURCE and QUAL, in the selection of sources
to be included.
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, 0=> all
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, 0=> all
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 which
case the task will request that you use FREQID.
UVRANGE....Range (min, max) of projected baselines to include
0,0 => all baselines (units: klamda)
TIMERANG...Time range of the data to be selected. In order: Start
day, hour, min. sec, end day, hour, min. sec. Days
relative to ref. date. start >= stop means get the start
and or stop times from the data themselves.
STOKES.....The desired Stokes type of the output data:
'LR','HALF' (=RR,LL), 'FULL' (=RR,LL,RL,LR)
BIF........First IF to plot. 0=>all.
EIF........Highest IF to plot. 0=>all higher than BIF
BCHAN......First channel to select. 0=>all.
ECHAN......Highest channel to select. 0 => max
If ECHAN>BCHAN then the data are averaged over the range
of frequency channels BCHAN-ECHAN within a given IF
before the fringe rate spectrum is generated.
SUBARRAY...Subarray number to select. 0=>all.
ANTENNAS...A list of the antennas to be plotted. If any number is
negative then all antennas listed are NOT to be plotted
and all others are.
BASELINE...Baselines between antennas named in ANTENNAS and those
named in BASELINE are selected. There are four possible
combinations of ANTENNAS and BASELINE:
1. ANTENNAS = 0; BASELINE = 0.
All possible baselines are selected.
2. ANTENNAS <>0; BASELINE = 0.
a)All ANTENNAS > 0
Baselines including an antenna in the ANTENNAS list
b)Some ANTENNAS < 0
All baselines NOT including an antenna in the ANTENNAS
list are selected;
3. ANTENNAS = 0; BASELINE <> 0.
a)All BASELINE > 0
Baselines including an antenna in the BASELINE list
b)Some BASELINE < 0
All baselines NOT including an antenna in the BASELINE
list are selected;
4. ANTENNAS <> 0; BASELINE <> 0.
a)All ANTENNAS>0 and all BASELINE>0
Baselines between antennas named in ANTENNAS and those
named in BASELINE are selected.
b)Some ANTENNAS<0 .OR. some BASELINE<0
Baselines between antennas named in ANTENNAS and
those named in BASELINE are DE-selected, all others
DOACOR.....> 0 => Include auto-correlations. If NPLOTS > 0, this
will include autocorrelation "baselines" as well as the
cross-correlations. If NPLOTS <= 0, DOACOR > 0 will
include only autocorrelations in the single plot. DOACOR
<= 0 will include only cross-correlations.
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
multisource 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 appply. <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
(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
BPVER......Specifies the version of the BP table to be applied (if
DOBAND > 0). 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
SHIFT......Desired position shift in the tangent point coordinates
in arcseconds to be made before plotting. The new
tangent point coordinates will be
RA' = RA + SHIFT(1) / cos(DEC) and
DEC' = DEC + SHIFT(2)
where all coordinates are in arcseconds.
APARM(1) sets the pre-average time interval to be used
before the FFT. Vector averaging is performed. If
APARM(1) = 0 then the pre-average time interval is equal
If APARM(2) is equal to 0 the axes of the plot will be
self-scaled. If APARM(2) is greater than 0 the scales are
set by the user using APARM(3) to APARM(6) and BPARM(5)
and BPARM(6) for the X axis (Hz or seconds)
APARM(3) = the minimum amplitude to be plotted.
APARM(4) = the maximum amplitude to be plotted.
Self-scaled if APARM(3) >= APARM(4).
APARM(5) = the minimum phase to be plotted.
APARM(6) = the maximum phase to be plotted.
Self-scaled if APARM(5) >= APARM(6).
N.B. phase is assumed to lie in the range -180.0 to 180.0
degrees. When NPLOTS > 1, user-scaled plots are shown
next to each other, while self-scaled plots "waste" space
with axis labeling.
APARM(7) selects the plot type.
0=> fringe rate spectrum;
1=> Visibility ampl/phase vs time.
The visibilities can be examined with APARM(7)=1 to check
for missing data before generating the fringe rate spectrum.
APARM(8) defines the zero padding to be used in the FFT.
0,1=> no padding; 2=> N zeroes added; 3=> 2N zeroes added
APARM(9) <= 0 will plot each IF and polarization
= 1, the spectra of the selected IF's will be
plotted side by side in the same frame.
= 2, the spectra of the selected polarizations
will be plotted side by side in the same
> 2, the spectra of the selected IFs and then
polarizations will be plotted side by side
in the same frame.
APARM(10) = 0 Do the normal full complex transform
= 1 Convert the complex data to amplitude 1.0
(i.e. examine phase issues only)
= 2 Convert the complex data to real (amp, 0)
(i.e. examine amplitude issues only)
CODETYPE...Selects which parameters are plotted from 'A&P',
'AMP ','PHAS','R&I','REAL','IMAG'. Others => 'A&P'
POLPLOT....An option to display the ratio of various correlated
values. Allowed combinations are: 'RL/RR', 'RL/LL',
'LR/RR', 'RL/LL', 'RR/LL', 'LL/RR', 'VH/VV', 'VH/HH',
'HV/VV', 'HV/HH', 'VV/HH', 'HH/VV', 'Q/I', 'U/I', 'V/I'
other => this option is not used.
The visibility data (not the relevant plots) are divided
before producing the plot. This turns off the multiple
polarization plotting (but not multiple IFs) of APARM(9).
SOLINT.....If SOLINT > 0 then the user can make multiple plots per
pass of FRPLT. All other parameters will be obeyed. FRPLT
will start at TIMERANG, make a plot covering the range
TIMERANG + SOLINT, etc. The units of SOLINT are minutes.
If SOLINT = -1 then FRPLT will make scan as the time step
starting at scan nearest to the start time specified in
TIMERANG and finishing at the scan end closest in time
to the stop time specified in TIMERANG.
If TIMERANG is all zero then
every scan will be averaged and plotted. This function is
predicated, of course, on there being an NX table in order
to determine the scan boundaries. The data must be in time
order for SOLINT not 0.
NPLOTS.....This adverb is used to control whether FRPLT plots multiple
spectra per page. If NPLOTS = 0 it will produce one plot
and all selected data will be averaged together to produce
that plot. The only exception is when SOLINT is non-zero in
which case data within the specified average intervals are
averaged and plotted, the task will then loop back for the
next time interval. If NPLOTS >= 1 then each baseline
will be plotted in a separate frame on the page.
NPLOTS cannot be greater than 9 - or the labels are
BPARM......(1) = 1 => divide the line data by 'channel 0'.
Channel 0 is a 'VLAism' for the vector
averaged centre 75 percent of the observing band.
If BPARM(1)=1 then DOCALIB must be -1.
(2) > 0 specifies the first channel used to form
'channel 0'. Normally 'channel 0' is the center
75 percent of the band, setting this BPARM will
override the default.
(3) > 0 specifies the last channel used to form
(4) Drop all spectra for which the amplitude of
channel 0 is < BPARM(4) in Jy. This prevents
visibilities near nulls from contributing to
averages their very noisy ratios.
(5,6) if APARM(2) > 0, BPARM(5) and BPARM(6) set the X
axis minimum and maximum when BPARM(5) < BPARM(6).
= 0 , 0 -> self scale
(10) = 1 => don't write header info when writing to the
OUTTEXT. Normally, each spectrum which is written to
the outfile specified by OUTTEXT is prefaced by a text
describing the spectrum. Setting BPARM(10) = 1
prevents writing this preface. This would be useful if
it is desired to write multiple spectra to the outfile
and then plot them with minimal human intervention.
Note that even the column identifiers are not written
to the OUTTEXT. The columns of the output file are:
channel#, IF, polarization, frequency, velocity,
[Run FRPLT with BPARM(10) = 0 to check that this
description of the outfile format is current]
** Unfortunately, the resulting file may not be
properly sorted in either frequency OR velocity. This
should be done manually outside of AIPS; under UNIX
'sort -n +3 OUTTEXT' will produce frequency sorted
OUTTEXT....The name of a disk file into which the raw
spectrum to be plotted is written.
LTYPE......Labelling type, see HELP LTYPE for details:
1 = border, 2 = no ticks, 3 or 7 = standard, 4 or 8 =
relative to ref. pixel, 5 or 9 = relative to subimage
(BLC, TRC) center, 6 or 10 = pixels. 7-10 all labels
other than tick numbers and axis type are omitted.
Less than 0 is the same except that the plot file
version number and create time are omitted.
Add n * 100 to alter the metric scaling.
FACTOR.....FACTOR scales the plus signs used to mark samples. All
plot types are plotted with plus signs and all but phase
are also plotted with connected lines. Set FACTOR < 0 to
have the plus signs omitted from non-phase plots. FACTOR
> 100.0 causes a scaling of (FACTOR-100.0) to be used and
the connecting lines to be omitted. 0 <= FACTOR < 0.4
-> FACTOR=1 and -0.4 < FACTOR < 0 -> FACTOR=-1.
BADDISK....A list of disks on which scratch files are not to
be placed. This will not affect the output file.
DOTV........> 0 => plot directly on the TV device, otherwise
make a plot file for later display on one or
more devices (including the TV if desired).
GRCHAN......Graphics channel (1 - 7) to use for line drawing.
0 => 1.