AIPS NRAO AIPS HELP file for HLPEDITS in 31DEC24



As of Mon Jul 15 17:49:49 2024


HLPEDITS Run-time help for task EDITA (TY tables)

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FLAG TIME
This option allows you to flag (delete) the Tsys for a specific time.
Move the cursor to the time you wish to flag.  The vertical line will
follow it while the time and value of the Tsys nearest the cursor will
be displayed in the top left corner of the TV.  Once on the desired
time, hit button A or B to flag that time and loop for more, hit button
C to flag the time and return to the menu, and hit button D to return
to the menu with no further flagging.  As you flag a point, it is
changed in color in the editing and secondary area displays and may also
be changed in color in the plots of other antennas if those Tsys's are
also flagged..  Tsys's for other polarizations, IFs, and antennas may
also be flagged depending on the setting of the ALL vs ONE POLARIZ,
ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown at the bottom left of
the display).  Note that, if the display is so crowded that more than
one time is plotted at the indicated cursor position (in the horizontal
direction only), then a range of times is actually flagged.  This option
is available in expert mode with abbreviation Time and code letter T (or
t).  Use REPLOT to recompute and display the altered Tdif values.
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FLAG TIME RANGE
This option allows you to flag (delete) Tsys's from a range of times.
Move the cursor to the start or end time of the range you wish to flag.
The vertical line will follow while the time of the point under the
cursor will be displayed in the top left corner of the TV.  Hit button A
to switch to setting the other end of the time range.  Move the cursor
to the end point of the desired time range; the second line will follow.
Hit button A to switch between the begin and end times; hit button B to
flag the Tsys's in the specified range and loop to set another time
range; hit button C to flag the Tsys's and return to the menu; or hit
button D to return to the menu with no further flagging.  Tsys's for
other polarizations, IFs, and antennas may also be flagged depending on
the setting of the All vs ONE POLARIZ, ALL vs ONE IF, and ALL vs ONE
ANTENNA flags (shown at the bottom left of the display).  This option is
available in expert mode with abbreviation Rang and code letter R (or
r).  Use REPLOT to recompute and display the altered Tdif values.
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FLAG BELOW
This option allows you to flag (delete) the Tsys's having value below
a cutoff level.  Move the cursor to the lowest level you believe in your
data.  The horizontal line will follow while the value of the point
under the cursor will be displayed in the top left corner of the TV.
Hit button A or B to flag all Tsys's below the chosen level and loop to
do it again, hit button C to flag all Tsys's below the chosen level and
return to the menu; or hit button D to return to the menu with no
further flagging.  Tsys's for other polarizations, IFs, and antennas
may also be flagged depending on the setting of the ALL vs ONE POLARIZ,
ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown at the bottom left
of the display).  Note that the flagging is done on the basis of the
values of the selected Tsys type (Tsys or Tdif) of each polarization,
IF, and baseline individually.  This option is available in expert
mode with abbreviation Belo and code letter B (or b).    Use REPLOT to
recompute and display the altered Tdif values.
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FLAG ABOVE
This option allows you to flag (delete) the Tsys's having value above
a cutoff level.  Move the cursor to the highest level you believe in
your data.  The horizontal line will follow while the value of the point
under the cursor will be displayed in the top left corner of the TV.
Hit button A or B to flag all Tsys's above the chosen level and loop to
do it again, hit button C to flag all Tsys's above the chosen level and
return to the menu; or hit button D to return to the menu with no
further flagging.  Tsys's for other polarizations, IFs, and antennas
may also be flagged depending on the setting of the ALL vs ONE POLARIZ,
ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown at the bottom left
of the display).  Note that the flagging is done on the basis of the
values of the selected Tsys type (Tsys or Tdif) of each polarization,
IF, and baseline individually.  This option is available in expert
mode with abbreviation Abov and code letter A (or a).  Use REPLOT to
recompute and display the altered Tdif values.
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FLAG AREA
This option allows you to flag (delete) the Tsys's from a range of
times and a range of Tsys values.  Move the cursor to one corner of
the area you wish to flag.  The box outline will follow while the time
of the data sample nearest the cursor within the box time range and the
value corresponding to the cursor vertical position will be displayed in
the top left corner of the TV.  Hit button A to switch to setting the
opposite corner of the area.  Hit button A to switch between the
opposite corners; hit button B to flag the Tsys's in the specified
area and loop to set another area; hit button C to flag the Tsys's
and return to the menu; or hit button D to return to the menu with no
further flagging.  Tsys's for other polarizations, IFs, and antennas
may also be flagged depending on the setting of the ALL vs ONE POLARIZ,
ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown at the bottom left of
the  display).  Note that the flagging is based solely on the Tsys or
Tdif values in the polarization, IF, and baseline displayed in the
edit area.  When other polarizations, IFs, and baselines are also
flagged it is simply the same times as those selected within the box
in the edit area.  This option is available in expert mode with
abbreviation arEa and code letter E (or e).  Use REPLOT to recompute
and display the altered Tdif values.
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FLAG POINT
This option allows you to flag (delete) Tsys's one at a time by moving
the cursor to the Tsys and hitting buttons A or B.  If you hit button
C, the current point is deleted and the program returns to the menu.
Button D returns to the menu with no further deletion.  Tsys's for
other polarizations, IFs, and antennas may also be flagged depending
on the setting of the ALL vs ONE POLARIZ, ALL vs ONE IF, and ALL vs
ONE ANTENNA flags (shown at the bottom left of the display).  When
other polarizations, IFs, and baselines are also flagged it is simply
the same time as that selected by the cursor in the edit area.  The
cursor needs to be within 5 screen pixels of the Tsys and will take
the nearest sample if there is more than one within this radius.  This
mode is useful for isolated outliers in a crowded display, but is more
accurate in complex areas when used within a smaller frame.  This
option is available in expert mode with abbreviation pOin and code
letter O (or o).  This command flags only the selected point even if
multiple polarizations and/or IFs are displayed.    Use REPLOT to
recompute and display the altered Tdif values.
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FLAG QUICKLY
This option allows you to flag (delete) Tsys's one at a time by moving
the cursor to the sample (carefully keeping the left mouse button
untouched, i.e. up) and then clicking the left mouse button.  If you hit
buttons A, B, or C, the current point is deleted and the program returns
to the menu.  Button D returns to the menu with no further deletion.
Tsys's for other polarizations, IFs, and antennas may also be flagged
depending on the setting of the ALL vs ONE POLARIZ, ALL vs ONE IF, and
ALL vs ONE ANTENNA flags (shown at the bottom left of the display).
When other polarizations, IFs, and baselines are also flagged it is
simply the same time as that selected by the cursor in the edit area.
The cursor needs to be within 5 screen pixels of the Tsys and will
take the nearest sample if there is more than one within this radius.
This mode is useful for isolated outliers in a crowded display, but is
more accurate in complex areas when used within a smaller frame.  This
mode is very quick, but requires you to be very careful in your use of
the mouse and left mouse button.  This option is available in expert
mode with abbreviation Quik and code letter Q (or q).  This command
flags only the selected point even if multiple polarizations and/or
IFs are displayed.  Use REPLOT to recompute and display the altered
Tdif values.
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RESTORE TIME
This option allows you to un-flag (restore) the Tsys for a specific
time.  Move the cursor to the time you wish to restore  The vertical
line will follow while the time of the point nearest the cursor will be
displayed in the top left corner of the TV.  Hit button A or B to
restore the Tsys at that time and loop for more; hit button C to
restore the time and return to the menu; or hit button D to return to
the menu with no further restoration.  Tsys's for other polarizations,
IFs, and antennas may also be restored depending on the setting of the
ALL vs ONE POLARIZ, ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown
at the bottom left of the display).  Note that, if the display is so
crowded that more than one time is plotted at the indicated cursor
position (in the horizontal direction only), then a range of times is
actually restored.  Use REPLOT to recompute and display the altered
Tdif values.
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RESTORE AREA
This option allows you to un-flag (restore) the Tsys's from a range of
times and a range of Tsys values.  Move the cursor to one corner of the
area you wish to restore.  The box outline will follow while the time
of the data sample nearest the cursor within the box time range and the
value corresponding to the cursor vertical position will be displayed
in the top left corner of the TV.  Hit button A to switch to setting
the opposite corner of the area.  Hit button A to switch between the
opposite corners; hit button B to restore the Tsys's in the specified
area and loop to set another area; hit button C to restore the Tsys's
and return to the menu; or hit button D to return to the menu with no
further restoration.  Tsys's for other polarizations, IFs, and antennas
 may also be restored depending on the setting of the ALL vs ONE
POLARIZ, ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown at the
bottom left of the  display).  Note that the restoration is based solely
on the Tsys values in the polarization, IF, and baseline displayed
in the edit area.  When other polarizations, IFs, and baselines are also
restored it is simply the same times as those selected within the box in
the edit area.  Use REPLOT to recompute and display the altered Tdif
values.
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SMOOTH TIME RNG
This option allows you to smooth (time average) the Tsys's from a range
of times.  Move the cursor to one end of the time range you wish to
smooth.  The vertical line will follow while the time of the point
under the cursor will be displayed in the top left corner of the TV.
Hit button A to switch to setting the other end of the time range.  Move
the cursor to the end point of the desired time range; the second line
will follow.  Hit button A to switch between the begin and end times;
hit button B to smooth the Tsys's in the specified range and loop to
set another time range; hit button C to smooth the Tsys's and return
to the menu; or hit button D to return to the menu with no further
smoothing.  Tsys's for other polarizations, IFs, and antennas may also
be smoothed depending on the setting of the All POLARIZ, ALL IF, and
ALL ANTENNA flags (shown at the bottom left of the display).
Flagged Tsys's may receive "good" values in this process.  The Tsys is
smoothed even if the Tdif is displayed in the edit area.  Furthermore,
this operation may only be undone by the REREAD TIME RNG option.  See
ENTER SMOOTH PS for a description of the smoothing functions
available.  The basic 2-point smoothing is used solely to replace
flagged Tsys's.  Use REPLOT to recompute and display the altered Tdif
values.
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REREAD TIME RNG
This option allows you to re-read from the output file the Tsys's
from a range of times.  Move the cursor to one end of the time range you
wish to re-read  The vertical line will follow while the time of the
point under the cursor will be displayed in the top left corner of the
TV.  Hit button A to switch to setting the other end of the time range.
Move the cursor to the end point of the desired time range; the second
line will follow.  Hit button A to switch between the begin and end
times; hit button B to re-read the Tsys's in the specified range and
loop to set another time range; hit button C to re-read the Tsys's
and return to the menu; or hit button D to return to the menu with no
further re-reading.  Tsys's for other polarizations, IFs, and antennas
may also be re-read depending on the setting of the ALL vs ONE POLARIZ,
ALL vs ONE IF, and ALL vs ONE ANTENNA flags (shown at the bottom left
of the display).  The Tsys's are read from the output table.  Therefore,
if only one IF is in memory at a time, these re-read Tsys's may not be
the same as in the input table.  The display is updated as the Tsys's
are read.  Use REPLOT to recompute and display the altered Tdif values.
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ENTER VALUES
This option allows you to select points in the edit window and then type
on the terminal (main AIPS window) a new value for the Tsys of that
point.  A small plus sign appears in the edit window.  Move it to a
point and then press buttons A, B, or C.  The task will prompt you for
a new value which will be displayed on the TV if it fits in the current
plot.  If you hit button C (or D) the process stops, otherwise it
continues.  Use REPLOT to recompute and display the altered Tdif values.
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ENTER SMOOTH PS
This option allows you to type on the terminal (main AIPS window) the
type and parameter(s) of the smoothing function.  The current type and
parameter(s) are displayed at the lower left of the screen.  The process
of smoothing is based on two windows on the time axis.  The cursor is
used to set a time-range (t1-t2) to be smoothed.  Data from t1-W to
t2+W, where W is the smoothing function window, are passed into a
smoothing routine and the results used to replace the samples in the t1
through t2 range.  The functions are:

(1) 2PT   Replace Tsys at time t, if flagged, with the linearly
          interpolated value of the nearest sample above t and below t
          but within W/2 of t.
(2) 2PTH  Replace Tsys at time t with the average of the Tsys itself
          and the linearly interpolated value of the nearest sample
          above t and below t, but within W/2 of t.
(3) BOX   Replace Tsys at time t with the average of all Tsys's
          within W/2 of t.
(4) MWF   Replace Tsys at time t with the median of all Tsys's
          within W/2 of t.
(5) GAUS  Replace Tsys at time t with the weighted average of all
          Tsys's samples within W/2 of t, using a Gaussian function
          of abs(time-t) of FWHM of W2.
(6) EXP   Replace Tsys at time t with the weighted average of all
          Tsys's samples within W/2 of t, using a Exponential
          function of abs(time-t) of FWHM of W2.
(7) LINE  Replace Tsys at time t with the weighted average of all
          Tsys's samples within W/2 of t, using a linear function of
          abs(time-t) of FWHM of W2.

The ENTER SMOOTH PS asks you 2 or 3 questions: the first to set the type
which is case-insensitive but must be left justified, the second to set
W in integer seconds, and the third, if needed, to set the full-width at
half maximum for the Gaussian and linear weighting functions.  The
smoothing is done without regard for source.
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ENTER TSYS RNG
This option allows you to type on the terminal (main AIPS window) the
range of Tsys that will be plotted.  It asks you for two numbers, the
lower limit and the upper.  If the upper limit is > the lower limit,
every plot of Tsys will cover this range, leaving out any points outside
the range (so be careful).  If you type 0 x, where x <  0, then the
minimum of each plot will be 0 and the maximum will be self-scaling.
If you enter one or no numbers or if the second number is <= the first
(but not the 0 x, x < 0), each Tsys plot will be self-scaling.  The
new Tsys range, if selected, is displayed immediately on the TV unless
the HOLD TV LOAD option was selected.  In that case, the  status code
LOAD PENDING is shown and the DO TV LOAD option is displayed and must
be selected to see the new Tsys's.
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ENTER TDIF RNG
This option allows you to type on the terminal (main AIPS window) the
range of Tdif values that will be plotted.  It asks you for two numbers,
the lower limit and the upper.  If the upper limit is > the lower limit,
every plot of phase will cover this range, leaving out any points
outside the range (so be careful).  If you enter one or no numbers or
if the second is <= the first, all Tdis plots will be self-scaling.
The new Tdif range, if selected, is displayed immediately on the TV
unless the HOLD TV LOAD option was selected.  In that case, the status
code LOAD PENDING is shown and the DO TV LOAD option is displayed and
must be selected to see the new Tdif's.
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SET SCAN LENGTH
This option allows you to change the length in seconds of a "scan" which
is the time interval over which the running mean is determined for the
Tsys/-1 (aka Tdif) plots and editing.  The new Tsys/-1 data,
if selected, are displayed immediately on the TV unless the HOLD TV LOAD
option was selected. In that case, the status code LOAD PENDING is
shown and the DO TV LOAD option is displayed and must be selected to
see the new data.
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USE EXPERT MODE
This option allows you to disable the menu as a form of command input
and change to entering one-letter commands from the main AIPS window.
The commands must be left-justified and followed by a carriage return
and may be in either case.  Prompt line(s) appear in the window showing
4-letter abbreviations of the available commands with the one-character
code shown in upper case.  Enter H or h for a display of the codes and
their translation into menu items.  Enter X or x to exit the expert mode
and return to input via the menu.  Note that only some menu items are
available in this expert mode and the full help information (such as you
are now reading) is not available.
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DO TV LOAD
This option will cause the TV display to be updated completely.  It is
only displayed if you have previously selected the HOLD TV LOAD option.
The reason to do this is to delay the screen update while you change
more than one of its parameters, i.e., the Tsys's type, display range,
antenna to edit, and/or secondary antennas.  The status code LOAD
PENDING is shown as soon as you have made a change which has not been
displayed.  When you select the DO TVLOAD option, it is replaced with
the HOLD TV LOAD option.
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HOLD TV LOAD
This option will cause the TV display to remain unchanged until the DO
TV LOAD option is selected.  The DO TV LOAD option is displayed if you
have previously selected the HOLD TV LOAD option.  The reason to do this
is to delay the screen update while you change more than one of its
parameters, i.e., the Tsys's type, display range, antenna to edit,
and/or secondary antennas.  When you select this option, it is replaced
with the DO TV LOAD option.
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REPLOT
This option will redo the full TV plot.  It may be of use if the plot
has not updated as expected.  It is required to get a new computation
of Tdif  (Tsys /  - 1) after editing, smoothing, or restoration
operations.
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CHAR MULT
This option appears only when the task starts with characters that are
currently, or by default, larger than the minimum (7x9 pixels).  It
allows you to set the scaling factor to an integer between 1 and 5.  If
you enter a value outside this range, the character size is not changed.
The task tries to defend itself from menus that become too large for the
screen.
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EXIT
This option is used to exit the program.  If you have done any flagging
or smoothing, the Tsys's will be written back to the output TY table.
The output table will remain cataloged as the previous highest version
number plus one.
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ABORT
This option is used to exit the program.  The output TY table will be
destroyed.  Use this option if you have made no changes to the table, or
if you distrust the changes you may have made.
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NEXT POL/IF
If there are enough polarizations and IFs in the TY table, this option
lets you switch to the "next" correlator.  It selects the other
polarization (if there are 2) and also selects the next IF if the
initial polarization was the highest available.  Thus if there are R
and L polarizations, it goes from R/1 to L/1 to R/2 to L/2 to ...,
eventually circling back to R/1.  If CROWDED was true, this option
changes the display to a single correlator even if > 1 IF or
polarization was plotted when it was selected.  The new data are
displayed immediately on the TV unless the HOLD TV LOAD option was
selected.  In that case, the status code LOAD PENDING is shown and the
DO TV LOAD option is displayed and must be selected to see the new data.
This option is available in expert mode with abbreviation Quik and
code letter C (or c).
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SWITCH POLARIZ
If there are two polarizations in the Tsys table, this option lets you
switch between them to select the Tsys's to be displayed and used in
editing.  If CROWDED was true, then the display of both polarizations
at once is also selected by this SWITCH.  The Tsys's for the new
polarization are displayed immediately on the TV unless the
HOLD TV LOAD option was selected.  In that case, the status code
LOAD PENDING is shown and the DO TV LOAD option is displayed and must
be selected to see the new Tsys's.
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SWITCH ALL POL
This option lets you toggle between having the following flag, smooth,
and re-read commands apply to both polarizations and having them apply
only to the current polarization.  The status lines on the bottom left
of the TV screen reflect the current value of this option.
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ENTER IF
If you included more than one IF with adverbs BIF and EIF, this option
lets you select which one will be displayed and used in editing.  If
there are more than two IFs or CROWDED was true, you will be prompted
to type the number of the desired IF.    If CROWDED was true, you may
enter 0 to have all IFs displayed at the same time.  If there are just
two IFs (and CROWDED was false), the program simply switches to the
other one.  If flags are to be applied to a single IF, they are
applied to the IF selected with this option.  If all IFs were not read
into memory at the start of the job (due to lack of space), then the
Tsys's for the current IF are written to the output file (if any
flagging or smoothing might have been done) as the Tsys's for the new
IF are read in.  The Tsys's are immediately displayed on the TV
unless the HOLD TV LOAD option was selected.  In that case, the status
code LOAD PENDING is shown and the DO TV LOAD option is displayed and
must be selected to see the new Tsys's.
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SWITCH ALL IF
This option lets you toggle between having the following flag, smooth,
and re-read commands apply to all IFs, having them apply only to the
current IF, and having them apply to a range of IFs.  The last will
prompt you for the two IF numbers of a range of IFs.  If you only
enter one, then only that one IF will be flagged.  The status lines
on the bottom left of the TV screen reflect the current value of this
option.
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SWITCH ALL TIME
This option lets you toggle between having the following FLAG ABOVE and
FLAG BELOW commands apply to all times and having them apply only to the
times displayed in the current edit window (the time range of the
frame).
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SWITCH ALL SOURC
This option lets you toggle between having the following flag commands
apply to all sources and having them apply only to the selected sources.
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SWITCH ALL ANT
This option lets you toggle between having the following flag, smooth,
and re-read commands apply to all antennas and having them apply only to
the current antenna.  The status lines on the bottom left of the TV
screen reflect the current value of this option.
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ENTER ANTENNA
This option allows you to type on the terminal (main AIPS window) the
number of the antenna to be used for the main display and for editing.
The Tsys's for the new antenna are immediately displayed on the TV
unless the HOLD TV LOAD option was selected.  In that case, the status
code LOAD PENDING is shown and the DO TV LOAD option is displayed and
must be selected to see the new Tsys's.  The Tsys's for this primary
antenna are displayed over the current time frame in the editing area
and the Tdif's are displlayed in the secondary area.
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ENTER OTHER ANT
This option allows you to type on the terminal (main AIPS window) the
numbers of up  to ten other antennas to be displayed above the display
of the main editing and secondary windows.  These comparison displays
use the same time frame and parameter type as the editing window.  To
display fewer than ten other antennas, simply hit Enter after listing
those that you do want.  You may have no comparison windows if you want
to see the largest possible display of the main editing window (hit
Enter with no non-zero values for this option).  The Tsys's for the
new secondary antennas are immediately displayed on the TV unless the
HOLD TV LOAD option was selected.  In that case, the status code
LOAD PENDING is shown and the DO TV LOAD option is displayed and must
be selected to see the new Tsys's
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NEXT ANTENNA
This option lets you change to the next antenna in SNEDT's internal list
for your primary antenna.  The list of other antennas is not changed
unless the new antenna occurs there.  In that case, the new antenna is
removed from the list and a new higher numbered antenna is added at the
end of the list.  The edit and secondary viewing areas will now contain
data from the new primary antenna.  The data for the new antennas are
immediately displayed on the TV unless the HOLD TV LOAD option was
selected.  In that case, the status code LOAD PENDING is shown and the
DO TV LOAD option is displayed and must be selected to see the new data.
This option is available in expert mode with abbreviation Nant and code
letter N (or n).
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PLOT ALL TIMES
This option allows you to select the full time range of the Tsys's as
the range to be displayed in all windows.  The Tsys's for the new
time range are immediately displayed on the TV unless the HOLD TV LOAD
option was selected.  In that case, the status code LOAD PENDING is
shown and the DO TV LOAD option is displayed and must be selected to
see the new Tsys's.
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SELECT FRAME
This option allows you to select the time range in the Tsys's to be
displayed in the editing window using the TV cursor.  The Tsys's are
first re-displayed using the full time range in the Tsys's (unless
the full time range was already displayed).  Move the cursor to one end
of the desired time range.  Hit button A or B to switch to setting the
other time limit.  Note that you are allowed to make the time range as
large or small as you want.  Displays that have more than one time
plotted in a single horizontal TV pixel are harder to edit accurately
but will be quicker than having to do multiple frames when accuracy is
less essential.  Hit buttons A or B to switch to the other limit, hit
buttons C or D to select the frame and return to the menu.  The screen
is updated immediately, unless the HOLD TV LOAD option was selected.  In
that case, the status code LOAD PENDING is shown and the DO TV LOAD
option is displayed and must be selected to see the new Tsys's.  This
option is available in expert mode with abbreviation Fram and code
letter F (or f).
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NEXT FRAME
This option causes the current frame to change to the next higher time
range.  The "frame" is that time range in the Tsys's available for
editing in the edit window.  The width of the frame is not changed.  The
boundaries of the new current frame are shown in the top plot.  The
screen is updated immediately, unless the HOLD TV LOAD option was
selected.  In that case, the DO TV LOAD option is displayed and must be
selected to see the new Tsys's.
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PREVIOUS FRAME
This option causes the current frame to change to the next lower time
range.  The "frame" is that time range in the Tsys's available for
editing in the edit window.  The width of the frame is not changed.  The
boundaries of the new current frame are shown in the top plot.  The
screen is updated immediately, unless the HOLD TV LOAD option was
selected.  In that case, the status code LOAD PENDING is shown and the
DO TV LOAD option is displayed and must be selected to see the new Tsys's.
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TV ZOOM
This option allows you to set the zoom factor and center to blow up the
data plot for more accurate cursor positioning.  The display is actually
shown in zoom only during flagging, un-flagging and re-reading
operations (where zoom may help you point more accurately) and during
the setting of the zoom.  The cursor position controls the zoom center,
buttons A and B increment the zoom, button C decrements the zoom, and
Xbutton D ends the zoom setting and returns to the menu.  Instructions
appear on the terminal.  Note that selecting a small frame is more
accurate than simply blowing up a crowded display.
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OFF ZOOM
This option resets any zoom factors and zoom center.  The display is
actually shown in zoom only during flagging, un-flagging and re-reading
operations (where zoom may help you point more accurately) and during
the setting of the zoom.
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SHOW TSYS
This option specifies that Tsys values are to be displayed on the TV
and used in the editing.  The screen is updated immediately, unless the
HOLD TV LOAD option was selected.  In that case, the status code LOAD
PENDING is shown and the DO TV LOAD option is displayed and must be
selected to see the new Tsys's.  This option is available in expert
mode with abbreviation Quik and code letter S (or s).
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SHOW TSYS/-1
This option specifies that Tdif values are to be displayed on the TV
and used in the editing.  The screen is updated immediately, unless the
HOLD TV LOAD option was selected.  In that case, the status code LOAD
PENDING is shown and the DO TV LOAD option is displayed and must be
selected to see the new Tdif's.  This option is available in expert
mode with abbreviation Quik and code letter D (or d).
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AIPS