AIPS NRAO AIPS HELP file for UVFLG in 31DEC18



As of Sun Jul 22 6:34:31 2018


UVFLG: Task to Flag selected UV data on disk.

INPUTS

INNAME                             UV data (name).
INCLASS                            UV data (class).
INSEQ             0.0    9999.0    UV data (seq. #).  0 => high
INDISK            0.0       9.0    Disk unit #.  0 => any
INTEXT                             Text file name.
SOURCES                            Sources selected/deselected
CALCODE                            Calibration code
QUAL                               Qualifier: -1 => any
SUBARRAY                           Subarray number 0=>all.
                                   Elevation is flagged: 0=>1
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.
BCHAN            -1.0    9999.0    First frequency channel
ECHAN            -1.0    9999.0    Last channel 0=>all
BIF              -1.0    9999.0    First IF 0=>1
EIF              -1.0    9999.0    Last IF 0=>all
ANTENNAS                           Antennas
BASELINE                           Baselines with ANTENNAS
STOKES                             Stokes' parameters
OUTFGVER                           Flag table version number
                                      Used w single-source too
APARM                              1:flag elevations>APAR(1) deg
                                   2:flag elevations1
                                     0 => do not flag due to
                                       this reason
                                   4:>0 => Print source, time,
                                      baseline,  U,V of expected
                                      zero fringe rate (U=0)
                                     0 => do not print
                                   5: > 0 flag for shadowing
                                      shadow diameter in m
                                   6: flag for cross-talk
                                     (see help) BL in m
                                   7: Number lines to print if
                                      INTEXT is used 0 -> 100
OPCODE                             'FLAG','UFLG', 'REAS', 'WILD'
REASON                             Reason (24 char.)
DOHIST            -3.0      1.0    > 0 -> add to history

HELP SECTION

UVFLG
Type:  Task
Use:   Data can be flagged or unflagged by modifying a flag (FG)
       table.  This is done for both multi- and single-source data
       sets.  If many flagging criteria are to be supplied at once,
       they can be entered in a text file which is then read by
       UVFLG.

       There are three ways to remove one or more flags from the FG
       table.  OPCODE='REAS' compares only the reason given in the FG
       table with adverb REASON.  If they match, then the flag record
       is deleted.  OPCODE = 'WILD' is like REAS except that REASON
       may be typed with wild-card characters and full wild-card
       matching of the flag reason will be done.  OPCODE='UFLG' uses
       all adverbs including REASON (as does 'FLAG') but UFLG allows
       for special values of adverbs which say that a record does not
       have to match that parameter in order to be deleted.  For
       example, if BIF=-1, any value of the start IF in a flag record
       will be deleted if the other adverbs match.  If BIF is anything
       else, the start IF in the flag record must match the value of
       BIF in order for the flag record to be deleted.

       UFLG is rather demanding.  You may also use task TAFLG.  Set
       OPTYPE='>', APARM=0; BPARM=1,0; and then set BCOUNT and ECOUNT
       to the range of FG table row numbers you wish to flag.  See
       EXPLAIN for more examples of UFLG.
Adverbs:
  USERID.....User number. 0 => current, 32000 => any user.
  INNAME.....UV file name (name).       Standard defaults.
  INCLASS....UV file name (class).      Standard defaults.
  INSEQ......UV file name (seq. #).     0 => highest.
  INDISK.....Disk unit #.               0 => any.
  INTEXT.....Name of the text file containing flagging instructions.
             Adverb values are entered in a text file with
             descriptions of data to be flagged separated by a '/'.
             There can be up to 40000 selection criteria in the edit
             file.  See EXPLAIN UVFLG.
             If INTEXT is used, then adverbs such as TIMERANG, BIF,
             EIF.. are ignored. Only flagging by elevation and pulse
             cal works together with INTEXT.
             NOTE that each flag command of INTEXT is independent of
             all other commands.  The only adverbs that are remembered
             are DTIMRANG and TIMEOFF, which cannot, once set, be
             reset to zero.
  SOURCES....List of sources in a raw data file to be selected.  If
             any names begins with a '-' all sources listed are
             deselected (i.e. all others are).
             Special rule for UFLG: SOURCES = '-', ... means ignore
             source name, CALCODE, and QUAAL when deciding to unflag.
  CALCODE....Sources may be selected on the basis of the calibrator
             code in addition to the name:
                  '    ' => any calibrator code selected
                  '*   ' => any non blank code (cal. only)
                  '-CAL' => blank codes only (no calibrators)
                  anything else = calibrator code to select.
             Special rule for UFLG: see SOURCES.
  QUAL.......Restrict to sources matching this qualifier: -1 => any
  SUBARRAY...The subarray desired for the operation. 0=> all.
             0 => 1 for PC table flagging.
  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.
             -1 => ignore FREQID on UFLG
  TIMERANG...The specified time range.
     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 = 0 => Stop IAT = Start IAT
             Both = 0 => all times
             stop IAT = start IAT not 0, flag +/- 0.5 sec of
                        the stated time
             Times are NO LONGER altered from the user input
             except as stated above.  Remember that some
             displays of time are integerized, i.e., a displayed
             17 could be anywhere from 16.5 to 17.5.  You must
             now supply any desired rounding down (Start IAT)
             and up (Stop IAT) if you enter both times.
             Start IAT < 0 => ignore Start IAT on UFLG, unchanged on FLAG
             Stop  IAT < 0 => ignore Stop IAT on UFLG, can be trouble
             on FLAG
  BCHAN......The first frequency channel selected.
             -1 => ignore BCHAN on UFLG, 0 -> 1
  ECHAN......The last frequency channel selected.
             -1 => ignore ECHAN on UFLG, <=0 -> 0 on FLAG (means max)
  BIF........The first IF selected; -1 => ignore on UFLG, 0 -> 1
  EIF........The last IF selected; -1 => ignore on UFLG, 0 -> max
  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.  Applies to elevation flagging as a
             list of antennas to be flagged.  All 0 means do not care
             on UFLG - it will UFLG flags with specific antennas
             expressed in the flag.
  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.  See EXPLAIN UVFLG for examples.  Does not
             apply when doing elevation flagging.
  STOKES.....Specifies the Stokes types to be flagged
             Recognized values are 'I', 'Q', 'U', 'V', 'IQU',
             'IQUV', 'IV', 'RR', 'LL', 'LR', 'RL',
             'HALF'(=RR,LL), 'FULL' (=RR,LL,RL,LR)
             'CROS'(=RL,LR), '    '=>all stokes' types.
             Alternatively, the "mask" to be applied can be recognised
             e.g. "1001" for flag RR and LR.
             On UFLG, STOKES = '----' means do not pay attention to
             the Stokes-level flagging pattern.
  OUTFGVER...Specifies the version of the flagging table into which
             the flags are written (0 => highest, or 1 if no FG table
             exists) for all data sets.
  APARM......Flagging may be done on one of elevation, shadowing,
             pulse-cal issues, or the data specified in the other
             adverbs:

             Single and multisource flagging (unflagging) on elevation
             is possible using APARM(1) and APARM(2).  These specify
             the range in elevation in degrees over which data are to
             be flagged (unflagged).  APARM(1) >= APARM(2) => no
             flagging on elevation.  If APARM(1) = 0 and APARM(2) > 0,
             APARM(1) is set to -90.  Adverbs BCHAN, ECHAN, BIF, EIF,
             and BASELINE do not apply.  Normal values for APARM would
             be something like APARM = -90,10.

             If elevation flagging is not requested, you may choose to
             flag data based on shadowing of one antenna by another in
             the array.  APARM(5) gives the minimum baseline in meters
             before shadowing is thought to occur (e.g. 25 for the
             VLA).  If APARM(5) > 0, you may also set APARM(6) to the
             minimum baseline in meters below which cross-talk is
             likely to occur.  This deletes the single baseline which
             may cause shadowing if it shortens more but not the other
             baselines to the (pre)-shadowed antenna.  This would be
             meant to omit possible cross-talk when one antenna starts
             to see another in its near-in sidelobes.  Note that it is
             possible to 'UFLG' shadowing as well as 'FLAG' shadowing.

             Spurious fringes appear due to pulse cal injection, if
             the fringe rate is close to zero. These spurious fringes
             are self-averaged by the fringe rate stopping procedure
             if the fringe rate is not close to zero.  The time
             interval required to suppress the spurious fringes is
             calculated by Kogan int VLBA Test Memo No 58, 1998. This
             time interval depends on suppression factor (APARM(3))
             The greater the suppression factor the longer the
             flagging time interval will be.  The desired suppression
             factor is determined by APARM(3)>1.  The value of the
             suppression factor should be selected experimentally
             considering pcal tones output less than rms of noise.
             APARM(4)>0 allows to print source, time, baseline, and
             U,V of expected zero fringe rate (U=0) at the first line
             for each scan.  The following lines (for each scan) are
             the flagging intervals for each IF.

             All other flag selections are applied simultaneously. For
             example, setting a specific time range will cause only
             data below the elevation cutoff in that time range to be
             flagged (or unflagged). Elevation flagging can be
             combined to similar effect with antenna, baseline,
             Stokes, IF and channel selection.

               If all APARM=0 the flagging(unflagging) does not depend
             on elevation or shadowing, i.e. all data satisfying the
             other conditions are flagged or unflagged.

             APARM(7) controls the echoing of flags in INTEXT.  <0 =>
             no lines are echoed, =0 => 100 lines echoed, > 0 =>
             APARM(7) lines echoed.

  OPCODE.....Tells whether to flag or unflag the data.
             'FLAG' => flag the data,
             'UFLG' => unflag with adverbs including REASON
                       Note that the adverbs must match the flag or be
                       set to special "ignore this adverb" values.
                       Defaults are not applied for UFLG.
             'REAS' => unflag all that match REASON ignoring all other
                       adverbs
             'WILD' => unflag all that match REASON ignoring all other
                       adverbs and interpreting REASON as containing
                       wild-card characters
             other => 'FLAG'
  REASON.....Reason for flagging the data, up to 24 characters.
             ' ' on 'UFLG' means any reason; ' ' not allowed on 'REAS'
             If APARM(1) and APARM(2) are set and REASON is left blank
             then 'ELEVATION RANGE EXCLUDED' is used as a REASON
             If APARM(3) is set and REASON is left blank then 'small
             fringe rate' is used as a REASON
             On OPCODE 'WILD' this adverb is handled under special
             "wildcard" rules.  These rules determine which test
             strings (e.g. reasons in the FG table) match the
             user-specified string.  Except for '*', '?', and trailing
             blanks (when an * is present), all characters specified
             in REASON must exactly match the corresponding characters
             in the test string.  A '?' in REASON matches any single
             character in the test string.  An '*' in REASON matches
             0 or more characters in the test string.  Thus, REASON =
             '*' matches any test string.  reason = 'A?B*D' matches
             'ASBD', 'A BXYZD D', and 'A3B45678901D', but does not
             match 'ABCD' or 'ASBCDE'.
  DOHIST.....True means add the individual flags in the history file,
             else just record the use of UVFLG.  (True is > 0)

EXPLAIN SECTION

UVFLG:  Task to Flag selected UV data on disk.
Documentor: E.B.Fomalont
Related Programs: CLIP, PRTUV, UVPLT, UVCOP, PRTAB

                       PURPOSE

     UVFLG is a general-purpose editing task.  The user specifies a
time range, an antenna or correlator and a polarization channel etc.
Entries are made in the flagging ('FG') table.  The contents of the FG
file can be examined with AIPS task PRTAB and plotted with FGPLT.

As of AIPS version 15JUL95 UVFLG will accept two different formats of
the ascii files. The new format described below was introduced to
allow the ascii flagging files generated by the VLBA monitor system to
be read into AIPS FG tables with no user editing being required.
Previously users had to modify the day numbers to be 0-relative and
change the antenna names to their equivalent numbers read from the AN
table.  UVFLG can read both the new and the old format files in a
manner transparent to the users.

      The time syntax in AIPS is different than that in the DEC-10.
Time zero is defined as midnight of the first day in the data base and
four numbers are needed for the start time and end time of any edit.
These times are inserted in TIMERANG.

     If both the Start and Stop IAT times are zero, then all data in
the file are flagged.  All data within 0.5 seconds of the time range
specified will be flagged if the two times are equal (or the stop time
given is zero while the start time is not 0).  TIMES ARE NO LONGER
ADJUSTED BY UVFLG.  YOU MUST PROVIDE ANY ROUNDING DOWN AND UP TO
ACCOUNT FOR THE ACCURACY OF THE DISPLAYS FROM WHICH YOU DETERMINED THE
TIMES TO BE FLAGGED.  Remember that the numbers entered into AIPS are
floating point, so you can enter, particularly seconds, in decimal
fraction form.

INTEXT
     If more than one set of data are to be flagged a text file can be
read.  If INTEXT is used, then adverbs such as TIMERANG, BIF, EIF..
are ignored.  Only flagging by elevation and pulse cal works together
with INTEXT.

  ********************************************************************
      NOTE that each flag command (entry) of INTEXT is independent
      of all other commands.  The only adverbs that are remembered
      are DTIMRANG and TIMEOFF, which cannot, once set, be reset
      to zero.
  ********************************************************************
    Examples:
         INTEXT='disk$res:[username]flag.dat'     (VMS)
         INTEXT='myarea:flag.dat'                 (Unix)
            where MYAREA is an environment variable set before
            starting AIPS:
             percentsetenv MYAREA /mnt/username
This table will be read using a version of the Caltech KEYIN routine
and is free format; a "!" denotes that the rest of the line is a
comment, a " /" denotes the end of the entry.
    Adverbs are entered with the same name as in AIPS but with no
minimum match.  The '=' sign is optional and all expressions must be
enclosed in parentheses '(' and ')'. Elements of an array MUST be
separated by commas. Only one entry should be made on a given line of
the editing table although a given entry may span several lines.
Adverb values are initialized to their null values before each entry
in the table is read.  Up to 40000 editing entries may be made for
single source files; there is no limit for multi-source files.  Note
however, that if multiple baselines are specified, each will count as
one of the 40000 entries.

     The adverbs which may be entered in this table are:
SOURCES, SUBARRAY, TIMERANG, BCHAN, ECHAN, BIF, EIF, ANTENNAS,
BASELINE, STOKES, OPCODE, REASON, and FREQID.  Two additional keywords
may appear BFREQ giving the begin frequency in MHz of a flag and EFREQ
giving the end frequency of a flag in MHz.  If one of these is used,
both must be used and BCHAN, ECHAN, BIF, and EIF must not be used.
This allows a text file to list, for example, known RFI frequencies to
flag different data sets with a variety of IF and channel
configurations.

    In addition, a parameter TIMEOFF can be given which is the number
of seconds to add to the timerange to convert it to IAT times.  The
current value to correct UTC to IAT is about +24.0 sec.  In addition,
a parameter DTIMRANG can be given which is the number of seconds to
increase TIMERANG from each side i.e to subtract DTIMRANG from the
left border of TIMERANG and add DTIMRANG to the right border of
TIMERANG.  Note that CALCODE and QUAL are not included in the INTEXT
option directly.  Instead the adverb values are used for each flagging
command.  It is recommended to use blank and -1.

NEW FORMAT: UVFLG will now also accept adverbs ANT_NAME and
BAS_NAME in place of ANTENNAS and BASELINE. The original adverbs
are still valid though.

     In the following example entry in a RUN table all data on
day 1 between 01:00:00 and 01:05:00 IAT involving antenna 7 and
FREQID 3 is to be flagged:

! Flag Antenna 7 1/1:0:0 to 1/1:5:0; all IFs and frequencies,
! any vis. number in a single source data file:

 TIMERANG=1,1,0,0, 1,1,5,0 ANTENNAS=7 FREQID=3 /

NEW FORMAT is used whenever ANT_NAME is used in the flag command and,
in the new format, this entry might be typed as:

 TIMERANG=242,1,0,0, 242,1,5,0 ANT_NAME='KP' FREQID=3 /

where KP is antenna 7 in the data, 242 is the day number of the
observations.  The NEW format is assumed when ANT_NAME='xxx' is
specified (an antenna name inside quotes) in the current command.
The OLD format is assumed for times in all other commands.

     In the following example, for a multi-source data file,
Antenna 10, left circular polarization, is flagged for all
times on sources 3CXYZ and 0000-900 because the antenna is the
wrong color:

 ANTENNAS=10 SOURCES='3CXYZ','0000-900' STOKES 'LL'
 REASON='ANTENNA WRONG COLOR' /

Note: commas are not allowed between ADVERBS and there should
also be at least one blank before each "/" used to delimit an
entry.

SOURCES
     For multi-source data sets a list of sources may be specified.
If any of the names listed begin with a "-" then all sources listed
are deselected, i.e. the described operation will be performed on all
OTHER sources.  The "-" sign will be ignored in the consideration of
the source name.

ANTENNAS, BASELINE
  Antennas to be flagged are specified in array ANTENNAS.  If
any antenna number is negative the absolute value will be used
and all antennas listed will be deselected, i.e. the descriped
operation will be done on all OTHER antennas.

NEW FORMAT: The adverb ANT_NAME can replace ANTENNAS in the
new format. Following ANT_NAME will be the left-justified
name (<= 8 characters) and placed in quotes. If using ANT_NAME
there can be no deselection as described above. Only one
ANT_NAME can be specified per entry.  Time ranges on any flag command
that uses ANT_NAME must be in the NEW format, otherwise they are in
the OLD format.

     Baselines are specified with the BASELINE adverb.  If
BASELINE contains non zero elements then all baselines between
all antennas specified in ANTENNAS and those specified in
BASELINE are selected.  If ANTENNAS contains a negative entry
then all the specified operation will be carried out on all
baselines OTHER than those explicitly named.

NEW FORMAT: The adverb BAS_NAME can replace BASELINE in the
new format. Following BAS_NAME will be the left-justified
name (<= 8 characters) and placed in quotes.

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.


STOKES
     The Stokes type of the data to be flagged can be specified
as on of the following: 'I', 'Q', 'U', 'V', 'IQU', 'IQUV',
'IV', 'RR', 'LL', 'LR', 'RL', 'HALF'(=RR,LL) and 'FULL'
(=RR,LL,RL,LR),  '    '=>all stokes' types.  A given polarization for
antenna flagging can be specified by 'RR' or 'LL'.  Note that
specification of 'RL' or 'LR' will flag 'RL' AND 'RR' or 'LR' AND 'LL'
respectively.  To flag a particular fringe e.g.'RL', specify this
using the appropriate mask - in this case '0010'.  The order of the
mask bits is RR, LL, RL, LR.

OPCODE
     If OPCODE='FLAG' the specified data is to be flagged either by
entries in the flagging table.  If OPCODE='UFLG' then the flagging
table entries are set to be deselected if they match the specified
entry.  NOTE change: UFLG now unflags only records that match the
adverbs exactly, although many have magic values which implies that
they can be ignored.  Previously (before July 2008) if there were ANY
overlap in the specifications of data to be unflagged and an entry in
the flagging table then the entire table entry is flagged (deselected,
turned off).  Thus, if some range of the specifications in the table
entry are to remain flagged, these portions should be reflagged.  UFLG
is now much more demanding.  OPCODEs 'REAS' and 'WILD' (REAS with
wild-card conventions) do UFLG examining only the reason recording
with the flag.  Any that match are deselected.


REASON
     Entries made in a flagging table can be labeled with a reason
that the data was flagged.  OPCODE='REAS' can then be used to deselect
entries in the flagging table with this reason, ignoring all other
adverbs, thereby effectively unflagging the data.  The entry may be up
to 24 characters long.  REASON can also be used with OPCODE='UFLG' and
the other adverbs to unflag data selectively.


Added July 2008: UFLG example

Consider the following flag table (an edited PRTAB output from a VLBA
flag table):

 So  Su   FQ  Ant      timerange    IF   Ch   flgs   Reason

  1   1    1    6     0/14:09:58.0   1    1   1111   System idle
                0     0/14:10:02.6   4   16
  1   1    1    5     0/14:09:58.6   1    1   1111   Subreflector error
                0     0/14:10:04.5   4   16
  1   1    1    7     0/14:09:58.6   1    1   1111   Antenna off source
                0     0/14:10:08.5   4   16
  1   1    1   11     0/14:09:58.6   1    1   1111   Subreflector error
                0     0/14:10:04.6   4   16
  1   1    1    1     0/14:09:58.6   1    1   1111   Subreflector error
                0     0/14:10:04.5   4   16
  1   1   -1   13     0/14:10:11.7   1    1   1111   MIN ELEVATION 10 DEG
                0     0/14:11:25.1   0    0
  2   1    1    9     0/14:11:28.6   1    1   1111   Source change in progres
                0     0/14:11:36.5   4   16
  2   1    1    1     0/14:11:28.6   1    1   1111   Antenna off source
                0     0/14:11:37.5   4   16
  2   1    1    6     0/14:11:28.6   1    1   1111   Subreflector error
                0     0/14:11:34.6   4   16
  2   1    1    4     0/14:11:49.2   1    1   1111   Antenna off source
                0     0/14:11:54.2   4   16
  1   1    1    3     0/14:14:58.6   1    1   1111   Source change in progres
                0     0/14:15:05.5   4   16
  1   1    1    7     0/14:14:58.6   1    1   1111   Source change in progres
                0     0/14:15:06.5   4   16
  1   1    1    8     0/14:14:58.6   1    1   1111   Subreflector error
                0     0/14:15:04.5   4   16
  1   1    1    4     0/14:15:21.2   1    1   1111   Antenna off source
                0     0/14:15:27.2   4   16
  2   1    1    6     0/14:16:28.6   1    1   1111   Antenna off source
                0     0/14:16:38.5   4   16
  2   1    1    3     0/14:16:28.6   1    1   1111   Subreflector error
                0     0/14:16:34.5   4   16
  2   1    1    3     0/14:16:28.6   1    1   1111   Source change in progres
                0     0/14:16:35.5   4   16
  2   1    1    9     0/14:16:47.5   1    1   1111   Antenna off source
                0     0/14:16:53.5   4   16
  1   1    1    2     0/14:19:58.3   1    1   1111   Antenna off source
                0     0/14:20:04.3   4   16
  1   1    1    5     0/14:19:58.6   1    1   1111   Antenna off source
                0     0/14:20:09.5   4   16
  1   1    1    6     0/14:19:58.6   1    1   1111   Antenna off source
                0     0/14:20:09.5   4   16
  1   1    1    2     0/14:20:04.3   1    1   1111   Antenna off source
                0     0/14:20:28.3   4   16
  2   1    1    1     0/14:21:28.6   1    1   1111   Source change in progres
                0     0/14:21:35.5   4   16
  2   1    1    7     0/14:21:28.6   1    1   1111   Subreflector error
                0     0/14:21:35.6   4   16
  2   1    1    5     0/14:21:28.6   1    1   1111   Antenna off source
                0     0/14:21:38.5   4   16
  2   1   -1    9     0/14:21:34.4   1    1   1111   MIN ELEVATION 10 DEG
                0     0/14:24:57.7   0    0
  1   1    1   11     0/14:24:58.6   1    1   1111   Source change in progres
                0     0/14:25:05.5   4   16
  1   1    1    5     0/14:24:58.6   1    1   1111   Subreflector error
                0     0/14:25:04.5   4   16
  1   1    1    6     0/14:24:58.6   1    1   1111   Antenna off source
                0     0/14:25:09.5   4   16
  1   1    1    9     0/14:25:17.5   1    1   1111   Antenna off source
                0     0/14:25:23.5   4   16
  2   1    1    5     0/14:26:28.6   1    1   1111   Source change in progres
                0     0/14:26:35.5   4   16
  2   1    1    6     0/14:26:28.6   1    1   1111   Antenna off source
                0     0/14:26:38.5   4   16
  2   1    1    8     0/14:26:28.6   1    1   1111   Subreflector error
                0     0/14:26:34.5   4   16
  2   1    1   11     0/14:28:43.5   1    1   1111   Antenna off source
                0     0/14:28:49.5   4   16
  4   1    1    3     0/15:26:08.5   1    1   1111   Source change in progres
                0     0/15:26:15.5   4   16
  4   1    1    8     0/15:26:24.5   1    1   1111   Ellipsoid posn error
                0     0/15:26:29.5   4   16

To deselect the Ellipsoid flag(s) without deleting the others:

1. The easiest thing to do is
      OPCODE = 'WILD'; REASON = 'Ellipsoid*
   Note the lack of close quote on REASON and lack of any command
   after it on the line.  This command will deselect all antennas that
   have this reason (and all sources etc etc).

2. To limit the deselection to antenna 8 with this reason
      OPCODE = 'UFLG'; ANTEN=8,0; BASELI=0
      SOURCES = '-',' '; STOKES='----';
      SUBARRAY=1; FREQID=1; TIMER=-1; BIF=-1; EIF=-1;
      BCHAN=1; ECHAN=16
      REASON = 'Ellipsoid posn error
  where REASON, BCHAN, ECHAN, SUBARRAY, FREQID, ANTEN, and BASELINE
  are given valid values that must match and SOURCE, STOKES, BIF, EIF
  and TIMERANG are given "I don't care values" and do not have to
  match.  The STOKES, BIF, and EIF could be specified, but the SOURCE
  would require listing all sources in the data to be specified and
  the TIMERANGE would be hard to manage without the -1 code.

AIPS