AIPS HELP file for QUACK in 31DEC24
As of Fri Apr 26 7:44:54 2024
QUACK: Flags specified portion of scans of UV data
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 #
STOKES Limit flagging by Stokes
BIF 0.0 90.0 Limit flagging to BIF-EIF
EIF 0.0 90.0 Limit flagging
SOURCES Sources selected/deselected
SUBARRAY Subarray number 0=>all.
SELBAND Bandwidth to flag (kHz)
SELFREQ Frequency to flag (MHz)
FREQID Freq. ID to flag. -1=>all.
0=> first Freq. ID.
TIMERANG Time: start day,hr,min,sec
stop day,hr,min,sec.
ANTENNAS Antennas to flag
BASELINE Baselines with ANTENNAS
FLAGVER Flag table version number
0 => highest
OPCODE 'END ', 'BEG ', 'ENDB'
'TAIL'; ' ' => 'BEG '
REASON Reason (24 char.)
APARM (1) => Cutting time (min)
from end (ENDG) 0 => 2
(2) => Cutting time (min)
from beg/end (BEGB/ENDB)
0 => 0.1
(3) Back start of flagging
<0 => no padding (0 seconds)
0 => 0.5 seconds [default]
>0 => APARM(3) seconds
BADDISK Disks to avoid for scratch
HELP SECTION
QUACK
Task: This task will flag selected portions of scans in a
multi-source UV data set. All data EXCEPT the last APARM(1)
minutes can be flagged using OPCODE='END ' for a selected
set of scans. Alternately the first/last APARM(2) minutes in
each selected scan may be flagged using OPCODE='BEG '/'ENDB'.
One can also delete APARM(2) minutes of data following the end
of each scan, for those systems that may not get the word to
all telescopes at the same time, using OPCODE='TAIL'.
Flagging info is entered in the specified FG table and is based
on the scans defined in the NX table. If no NX table is
present, one can be created using task INDXR.
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.
STOKES.....Limit flags to specified Stokes value. ' ' = '1111'
Allowed values for RR/LL.. are 'FULL', 'HALF', 'RR',
'LL', 'RL', 'LR', 'RRLL', 'RLLR', and any combination of
4 1s and 0s (e.g. '1011' to delete all R polarizations).
BIF........Limit flag to IF beginning with BIF; 0 -> 1.
EIF........Limit flag to range BIF through EIF. 0, < BIF -> max.
SOURCES....List of sources in the data file to be flagged.
If any names begins with a '-' all sources listed
are deselected (i.e. all others are).
SUBARRAY...The subarray desired for the operation. 0=> all.
SELBAND....Bandwidth of data to be flagged. 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 flagged. If more than
one IF is present SELFREQ is the frequency of the
first IF required. Units = MHz, 0=> all
FREQID.....Frequency identifier to flag (you may determine
which is applicable from the OPTYPE='SCAN' listing
produced by LISTR. If either SELBAND or SELFREQ
are set their values overide 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. 0=> program will
select the first in the FQ table, -1=> flag all
FREQID values. Note this useage is slightly
different from that in other tasks.
TIMERANG...The specified time range; scans whose central time
is in this range will be affected.
1 = Start IAT day (day 0 = first day in data base)
2 = Start IAT hour
3 = Start IAT minute
4 = Start IAT second
5 = Stop IAT day (day 0 = first day in data base)
6 = Stop IAT hour
7 = Stop IAT minute
8 = Stop IAT second
stop IAT = start IAT = 0 =>, all times
ANTENNAS...A list of the antennas to be flagged. If any number is
negative then all antennas listed are NOT to be flagged
and all others are.
BASELINE...If any elements of BASELINE are non zero then all
baselines between antennas named in ANTENNAS and those
named in BASELINE are specified. If ANTENNAS contains a
negative value then all baselines NOT specified are
selected.
Examples:
If ANTENNAS = 1,2,3 and BASELINE = 4,5 then baselines
1-4, 2-4, 3-4, 1-5, 2-5 and 3-5 are selected.
If ANTENNAS = -1,2,3 and BASELINE = 4,5 then ALL baselines
EXCEPT 1-4, 2-4, 3-4, 1-5, 2-5 and 3-5 are selected.
FLAGVER....The version of the flagging (FG) table in which to
make the entries.
0 => highest, or 1 if no FG table exists
OPCODE.....Tells type of flagging:
'END ' => flag all but APARM(1) min from end of
scan.
'BEG ' => flag first APARM(2) min of each scan
'ENDB' => flag last APARM(2) min of each scan
'TAIL' => flag APARM(2) min after each scan
' ' => 'BEG '
REASON.....Reason for flagging the data, up to 24 characters. This
string will be inserted in the FG table and may be used
by UVFLG to unflag this data if you later decide to do
so. ' ' => 'QUACK dd-mmm-yy hh:mm:ss' where the date and
time is filled in.
APARM......(1) => Cutting time (min) from end (ENDG) of each
scan to keep, the rest is flaged. 0 => 2
(2) => Cutting time (min) from beginning or end of each
scan to flag. 0 => 0.1
(3) Back start (forward stop) of flagging to include
the scan edge.
<0 => no padding (0 seconds)
0 => 0.5 seconds [default]
>0 => APARM(3) seconds
A value about a fourth of the integration time of the
integration time will protect from inaccuracies in
the times due to floating-point formats.
See EXPLAIN for details of the actual flag times used.
BADDISK....The disk numbers to avoid for scratch files (sorting
tables mostly).
EXPLAIN SECTION
A note on the exact times used. Assume that a particular scan is said
in the NX table to run from T0 to T1 (T0 = TIME - 0.5* DTIME,
T1 = TIME + 0.5*DTIME where TIME and DTIME are in the NX table). Also
define
TB = APARM(1)
TE = APARM(2)
CC = APARM(3)
Then
OPCODE 'END ' flags from T0 - CC through T1 - TB
'BEG ' T0 - CC T0 + TE
'ENDB' T1 - TE T1 + CC
'TAIL' T1 + CC T1 + TE
The first three do just the specific source, the last does all
sources.