AIPS HELP file for UVFLG in 31DEC21
As of Sun May 16 19:33:45 2021
UVFLG: Task to Flag selected UV data on disk.
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
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
BASELINE Baselines with ANTENNAS
STOKES Stokes' parameters
OUTFGVER Flag table version number
Used w single-source too
APARM 1:flag elevations>APAR(1) deg
0 => do not flag due to
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
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
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.
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
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
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. This option supports
moving sources if there is a PO table with their
coordinates as a function of time.
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. This option supports moving sources if there
is a PO table with their coordinates as a function of time.
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. This option does not
support moving sources even if a PO table is present.
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
'WILD' => unflag all that match REASON ignoring all other
adverbs and interpreting REASON as containing
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)
UVFLG: Task to Flag selected UV data on disk.
Related Programs: CLIP, PRTUV, UVPLT, UVCOP, PRTAB
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
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
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
where MYAREA is an environment variable set before
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
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
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
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 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.
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.
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.
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.
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
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;
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.