; IBLED ;--------------------------------------------------------------- ;! Interactive BaseLine based visibility EDitor ;# TASK UV VLBI CALIBRATION EDITING TV-APPL INTERACTIVE ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 1997, 1999-2004, 2006-2010 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- IBLED LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC IBLED Task to edit data baseline-by-baseline using the TV 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 # DOCAT -1.0 2.0 Catalog work file ? IN2SEQ 0.0 Sequence number of work file IN2DISK 0.0 9.0 Disk on which to write work file, 0 => any DOHIST -3.0 1.0 Record flags in history file SOURCES Source list CALCODE Calibrator code ' '=>all Source model to plot: IN3NAME CLEAN map name (name) IN3CLASS CLEAN map name (class) IN3SEQ 0.0 9999.0 CLEAN map name (seq. #) IN3DISK 0.0 9.0 CLEAN map disk unit # IN3VER -1.0 46655.0 CC file version # NMAPS 0.0 4096.0 No. CLEAN map files NCOMP # comps to use for model. 1 value per field FLUX Lowest CC component used. TIMERANG Time range to include STOKES Stokes type to display SELBAND Bandwidth to select (kHz) SELFREQ Frequency to select (MHz) FREQID Freq. ID to select. BIF 0.0 1000.0 Lowest IF number 0=1 EIF 0.0 1000.0 Highest IF number BCHAN 0.0 8192.0 Lowest channel number 0=>1 ECHAN 0.0 8192.0 Highest channel number ANTENNAS Antennas to edit. BASELINE Baselines with ANTENNAS UVRANGE 0.0 UV range in kilolambda SUBARRAY 0.0 1000.0 Subarray, 0 => all Cal. info for input: DOCALIB -1.0 101.0 > 0 calibrate data & weights > 99 do NOT calibrate weights GAINUSE CAL (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 0 => high < 0 no flagging on input Used w single-source too OUTFGVER 0.0 Output FG 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. Task enrichment parameters: DPARM (1) 0 => display amplitude 1 => display phase, can change interactively (2) if > 0, include autocorrelation data (3) if > 0 will average IFs selected with BIF to EIF (4) input data interval in secs. <=0 -> 10 PLEASE SET 4 & 5 ! (5) data averaging time in secs: <=0 => >= 10 (6) If > 1, plot error bars, can change interactively (7) Min value to plot, can be changed interactively. 0 => use min. in data (8) Max value to plot, can be changed interactively. 0 => use max. in data (9) If > 1, don't plot whole visibility function along the top of the screen, can change interactively BADDISK Disks to avoid for master and scratch files ---------------------------------------------------------------- IBLED Type: Task Use: To edit visibility data interactively. This task is complementary to TVFLG and will be mainly useful for editing data from interferometers with a relatively small number of baselines (e.g. VLBI experiments). The visibility function for a single baseline is displayed on the TV device and the user has various editing options (all under a menu-like control interface) available to flag bad data. There are also various display and data selection options available in the menu. For multi-source data a flagging (FG) table is written;, for single-source data the flagging information is applied at the end of the editing sessions. IBLED is for editing continuum data from one or more IFs. Multiple spectral channels may be averaged in the master file used for display and editing, while multiple IFs may be averaged together or kept separate. These averagings as well as an option time averaging may be used to find the ratio of the vector- to scalar-averaged amplitudes. This will be 1.0 for stable data of high signal-to-noise and near 0 for signal-free data. This ratio may be displayed and used in editing in addition to the displays and uses of the vector-averaged amplitude and phase. If the IFs are kept separate, one may also display and edit the ratio in amplitude or difference in phase of one IF to a second. 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. DOCAT......True (>0) means to use a cataloged file for the "master file". It creates a new one or uses an old one, depending on the value of IN2SEQ. One can run IBLED a number of times using the same master file, before applying the final list of flag commands to the input data file. (The master file is destroyed when the flag commands are applied or, if DOCAT <= 0, on EXIT.) If DOCAT = 2 and IN2SEQ = 0, then the program returns to the user immediately, prepares the cataloged master file, and then exits. The program must be rerun with an appropriate, non-zero value of IN2SEQ to flag the data. This option allows the user to do other things while creating a large master grid file. IN2SEQ.....Sequence number of cataloged master grid file. 0 => create new one, else use existing one of seq number = IN2SEQ. NOTE: to use this option, all of the adverbs must have the same value as when the old grid file was created. IN2DISK....Disk on which to write the catalogued work file, 0 => choose a disk, avoiding those in BADDISK. DOHIST.....> 0 => record task execution and flagging info in the history file (this can be a lot!). <= 0.0 means to omit the flagging info and < -1.5 means to omit the execution information as well. SOURCES....List of sources to be displayed. ' '=> all; if any starts with a '-' then all except ANY source named. CALCODE....Sources may be selected on the basis of calibrator code: ' ' => any calibrator code selected '* ' => any non blank code (cal. only) '-CAL' => blank codes only (no calibrators) anything else = calibrator code to select. IN3NAME....Source model file name. If selected, a plot of the model amplitude will appear as an overlay in the lower frame. This can be selected or de-selected using the "PLOT MODEL" option on the left-hand menu. The model will not be plotted for phase or de-correlation data. Models made with either value of DO3DIMAG in IMAGR are supported. IN3CLASS...Source model file class IN3SEQ.....Source model file sequence number IN3DISK....Source model disk number IN3VER.....CC file version # for source model file For a multi-source file, the flux of the clean components selected for the model are summed and scaled to the source flux found in the SU table. If that flux is zero, no scaling is done. NMAPS......Number of image files to use for model. For multi-scale models, set NMAPS = NFIELD * NGAUSS to include the Clean components of the extended resolutions. If more than one file is to be used, the NAME, CLASS, DISK and SEQ of the subsequent image files will be the same as the first file except that the LAST 3 or 4 characters of the CLASS will be an increasing sequence above that in IN2CLASS. Thus, if INCLASS='ICL005', classes 'ICL005' through 'ICLnnn' or 'ICnnnn', where nnn = 5 + NMAPS - 1 will be used. Old names (in which the 4'th character is not a number) are also supported: the last two characters are '01' through 'E7' for fields 2 through 512. In old names, the highest field number allowed is 512; in new names it is 4096. NCOMP......Number of Clean components to use for the model, one value per field. If all values are zero, then all components in all fields are used. If any value is not zero, then abs(NCOMP(i)) (or fewer depending on FLUX and negativity) components are used for field i, even if NCOMP(i) is zero. If any of the NCOMP is less than 0, then components are only used in each field i up to abs(NCOMP(i)), FLUX, or the first negative whichever comes first. If abs(NCOMP(i)) is greater than the number of components in field i, the actual number is used. For example NCOMP = -1,0 says to use one component from field one unless it is negative or < FLUX and no components from any other field. This would usually not be desirable. NCOMP = -1000000 says to use all components from each field up to the first negative in that field. NCOMP = -200 100 23 0 300 5 says to use no more than 200 components from field 1, 100 from field 2, 23 from field 3, 300 from field 5, 5 from field 6 and none from any other field. Fewer are used if a negative is encountered or the components go below FLUX. FLUX.......Only components > FLUX in absolute value are used in the model. TIMERANG...Time range of the data to be displayed. In order: Start day, hour, min., sec, end day, hour, min., sec. in days relative to reference date. STOKES.....The desired Stokes type of the data for display and editing. It is probably a good idea to view the data without Stokes conversion, i.e., STOKES = ' '. However, there may be times when conversion to, say, STOKES = 'IQUV' may make sense. Note that a flag of Stokes I flags both RR and LL. The value of STOKES controls the default set of polarizations (correlators) to be flagged. However, you may enter interactively any desired and reasonable set. 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 overide that of FREQID. However, setting SELBAND and SELFREQ may result in an ambiguity. In that case, the task will request that you use FREQID. BIF........Lowest IF to grid. Note that unless you have requested the selected IF's to be averaged together (see DPARM(3)) then the first IF displayed on the TV will be BIF, other IF's can then be displayed interactively by selecting them from the menu. ************************************************** NOTE to VLA users: IF=1 corresponds to the VLA AC ifpairs and IF=2 corresponds to the BD ifpairs. ************************************************** EIF........Highest IF to grid. 0 => highest. BCHAN......First channel to AVERAGE together. 0 => 1. ECHAN......Last channel to AVERAGE. 0 => highest. ANTENNAS...A list of the antennas to edit. If any number is negative then all antennas listed are NOT desired and all others are. All 0 => edit all. BASELINE...Baselines to be edited, use BASELINE and ANTENNAS. Eg. baselines 1-6,1-8, 2-6 and 2-8 use ANTENNAS=1,2; BASELINE=6,8. UVRANGE....Range of projected spacings to be gridded in 1000's of wavelengths. 0 => 1, 1.E10 SUBARRAY...Subarray number to grid. 0 => all. If you have multi-source data with more than one source at a time, then you will need to specify the SUBARRAY and do one of them at a time. 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 Cal. table to apply to the data if DOCALIB=1. Refers to a CL table for multi-source data or an SN table for single-source. 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 for reading the data. FLAGVER = -n => no flagging on input. OUTFGVER...Flag table version to be used on output for both single- and multi-source data sets. If OUTFGVER is <= 0 or greater than FGmax (the previously highest FG version number), then a new FG table will be created for the new flags with version FGmax+1. This new table will also contain the flags applied on input (if any) from FG version FLAGVER. If OUTFGVER specifies a pre-existing FG version, then the input flags are not copied even if OUTFGVER and FLAGVER are not equal. 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 corrected. (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 corrected. BPVER......(multi-source) specifies the version of the BP table to be applied. 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 SMOOTH(2). DPARM......(1) = 0 => display amplitudes for editing = 1 => display phases for editing These can be interactively toggled within the task. (2) if > 0, autocorrelation data will be calibrated and averaged into the master file (3) if > 0 will average IFs BIF through EIF. (4) Normal integration time found in the data. PLEASE PROVIDE THIS NUMBER. 0 => 10 seconds to the routine that reads in the data averaging and calibrating them. Then a new integration time will be used based on the averaged data of the first baseline. (5) Data samples within DPARM(5) seconds are averaged after calibration. This averaging along with averaging over IFs and/or spectral channels provides the estimate of the decorrelation. IT IS BEST TO SET THIS VALUE. If DPARM(5) <= 0, the task will average the data to 10 seconds and then read through the averaged data of the first baseline and set the sampling to the minimum interval found (>= 10 seconds). (6) if > 1 then IBLED will assume that the weights associated with the data are correctly scaled so as to be easily related to true error bars and will plot them as such. The default is not to plot error bars and to represent each datum with the same size vector on the TV. This can be changed interactively. (7) Minimum amplitude (Jy) (or phase (degrees)) to be displayed. (8) Maximum amplitude (Jy) (or phase (degrees)) to be displayed. Both DPARM(6) and (7) can be set interactively also. (9) If = 0 => plot the whole of the visibility function for the particular baseline across the top of the TV. Normally a baseline will have more data points than there are pixels across the TV so IBLED will only plot part of the data in the main editing frame, however it is useful to be able to see the whole visibility function while only editing part of it, this option enables the user to do that. If DPARM(9) = 1 then the whole visibility function will not be plotted. This can be changed interactively. (10) BADDISK....List of disks to avoid for BOTH scratch files and the master file (if OUTDISK = 0). ---------------------------------------------------------------- IBLED has three main steps: (1) The data are selected and calibrated using all of the usual calibration adverbs and options. Then they are averaged over spectral channels BCHAN through ECHAN, over IFs BIF through EIF (if DPARM(3) > 0), and over DPARM(5) seconds of time. The resultant visibilities are written to a "master file" which is cataloged temporarily or (semi) permanently on disk INDISK2 with class IBLEDR. Each visibility record in this file consists of a weight, vector-averaged amplitude, vector-averaged phase, and "decorrelation" index (ratio of vector-averaged to scalar-averaged amplitude). For autocorrelation data, the amplitude is the real part (with sign) and the decorrelation is the rms in the real part. This master file can be used in one or, if DOCAT > 0, more than one session of step (2) below to prepare flag commands which are stored in an FC table attached to the master file. (2) The session(s) in which the user interacts with his data arranging the TV display and then selecting which data are to be flagged. The data are plotted with time along the X axis plotting one point per TV pixel and skipping 20 pixels between scans. Therefore, the time axis is quite non-linear. Tick marks are placed at integer hour points along the X axis and the end points labeled to provide you with some idea of the times. All interactive editing operations provide detailed displays of the currently selected time and visibility. The main editing area may not be large enough to contain all the data. In this case, a smaller "frame" of data is selected and you may alter the selected frame to gain access to all of your data. A small plot at the top of the screen shows all of the data, potentially with a fairly crowded X (time) axis. (3) The actual flagging of the data and writing of the history file. A flag table is written for multi-source files and the uv data themselves are flagged for single-source files. This should be done when exiting if you have not cataloged the master file (i.e. DOCAT <= 0) or when you are fully satisfied with your flag commands. When the flags are applied to the input data set, the master file is deleted. The interactive session is driven by a menu which is displayed on the same screen as the data. Move the cursor to the desired operation (noting that the currently selected one is highlighted in a different color on many TVs) and press button A, B, or C to select the operation. Press button D for a short explanation of the selected operation. The first column contains options to alter the display of the data and the choice of which data are flagged ultimately. The second column has 7 interactive modes for selecting data to be flagged, 2 operations on the FC table itself, and 10 operations which cause the display to be changed. When the menu is displayed, one or more lines of status information are displayed at the bottom of the screen. The line that is always present shows the type of data displayed and which Stokes and whether one or all sources, IFs, and channels will be flagged by the next flag commands. If all baselines to on or both of the displayed antennas will be flagged and/or if the points are currently plotted with error bars, a second line reflecting this fact will be displayed. If the Stokes type, the first or second IF, or the error bar type will change on the next LOAD, then another line is displayed saying "NEXT LOAD SHOWS" these new things. Finally, if some data are omitted from the plot due to user-selected plot scaling, then another line appears warning of this fact. The plot of the data is labeled along the vertical axis by normal labeled tick marks and the units, while the horizontal axis has ticks at integer hours and time strings at both ends of the plotted data. The line at the top of the plot identifies the data currently displayed. The left-hand menu section begins with 3 operations to alter the TV display zoom and color transfer functions. The zoom is useful for greater accuracy in selecting data to be flagged. Then there are 3 options to set the range of amplitude, phase, and decorrelations which are actually plotted. These default to the full range in the current data, and can be set back to default by entering 0 0. The next two options ask you to enter the desired IF number and Stokes type for the next display, but do not actually change the display. Use any of the redisplay options in the second menu (LOAD is simplest) to update the display. The next option allows you to specify a second IF number. When that is not 0 and not the same as the first IF, IBLED plots the amplitude ratio or phase difference of the first IF and the second IF. The next 5 options switch the binary states of several flags: the first controls the plotting of the full data set in the small plot at the top, the second controls the vertical bars plotted about the data switching betwen error estimates and a small constant, and the rest control whether one or all spectral channels, IFs, and sources are flagged by the following flag commands. The next option allows you to set the Stokes which will be flagged by the following flag commands (see below). And the final 2 options allow you to switch between flagging only the displayed baseline and flagging all antennas to one or both of those displayed. The last two menu items actually reflect the station names for the two antennas and change as you change baselines. The menu looks like: ------------------- | OFF ZOOM | To turn off any zoom magnification | OFF ENHANCEMENT | To turn of black & white and pseudo-color enhancements (usually top plot only) | TVFIDDLE | To do interactive zoom, pseudo-color contours, or black and white enhancement | ENTER AMP RANGE | To type in the intensity range to be used for plotting amplitudes (Jy or ratio) | ENTER PHS RANGE | To type in the phase range to be used for plotting phases (degrees) | ENTER DCR RANGE | To type in the decorrelation range to be used to plot decorrelation (0-1 or ratio) | ENTER IF | To enter on the terminal the desired IF to be displayed next. | ENTER STOKES | To enter on the terminal the STOKES type to be displayed next. | RATIO 2ND IF | To enter on the terminal the IF to divide into the first IF to display ratios of data . 0 turns off this option. | SHOW TOP PLOT | To toggle switch to display complete data for current baseline along top of screen | PLOT MODEL | To toggle between displaying and not displaying the model visibility (when selected by adverbs) | PLOT ERROR BARS | To toggle switch to plot error bars or a small constant bar - works only with fully calibrated data weights. | SWTCH 1-CH FLAG | To toggle between flagging all spectral channels and only BCHAN-ECHAN. | SWTCH 1-IF FLAG | To toggle between flagging all IFs or only the one shown (or BIF-EIF if averaged). | SWTCH 1-SO FLAG | To toggle between flagging all sources in any time range and only those displayed. | SET STOKES FLAG | To enter on the terminal the 4-character string which will control which correlators (polarizations) are flagged. Note: this parameter applies only to flag commands prepared after it is set. It should be changed whenever a different Stokes is displayed. See also below. | FLAG station1 | To toggle switch between flagging all data to this antenna and only station2. | FLAG station2 | To toggle switch between flagging all data to this antenna and only station1. ------------------- The all-channel flag remains true if the full range of channels in the input data set are averaged in the data being flagged. The all-IF flag remains true if the full range of IFs in the input data set are averaged in the data being flagged. The right-hand menu section begins with 8 flagging operations: to flag one time at a time, to flag a range of times, to flag an area in the intensity-time plane, to flag all points above some intensity or below some intensity, to flag all points more than x times the rms from the mean, to flag all points above or below a user-drawn curve in the intensity-time plane, and lastly, to flag all times in all frames for the displayed data. During the first 7 operations the current position selected by the cursor is displayed in the upper left hand corner of the TV with source name, time, flux, and (optionally) error. Lines or boxes are also drawn in the TV to indicate the area being selected for flagging. During interactive flagging, button A switches between corners or end times except for FLAG TIME where it does the flagging and FLAG INTERACTIV where it marks a point. Button B does the flagging and loops for more except for FLAG INTERACTIV where it marks another point on the curve. Button C also does the flagging, but the program then returns to the main menu rather than prompting for more flagging selections. Button D exits back to the menu without doing any additional flagging. When a flagging command is generated, any flagged data currently displayed are erased (only from the lower plot) and some number of records are written into the FC table. Note that one can flag only those data in the current frame using the intensity type in the current display (plus other IFs, Stokes, etc. as chosen by the flagging control commands). You must visit other frames in order to flag them. The last flag operation, FLAG ALL TIME, is not interactive and simply flags all data for the displayed baseline (or antenna) for all times in all frames. The next two operations in the right-hand menu allow you to list the flag commands already in the FC table and to undo any of them. The UNDO FLAGS peration prompts you for a list of flags to be undone by number (get these from LIST FLAGS) with 0 ending the list. When a flag is undone, all cells in the master file which were first flagged by that command are restored to use, except for those also flagged by some later command. This is done automatically by IBLED without the special commands required by TVFLG. After an UNDO FLAGS operation, the TV is reloaded, potentially with new plot scales. The next 10 operations in the right-hand menu also cause the display to be updated immediately if needed. The first three select the type of data to be displayed and used in flagging; the next four change the current frame (portion of the current baseline) being displayed and edited; the next two change the current baseline, and the last forces an update of the screen including the top plot in case some of the changes (e.g. flagged points, new IF or Stokes selection, etc.) have not been fully reflected in the displays. The SELECT FRAME uses the top plot to select the desired frame interactively and can work only when the top plot is displayed. The last option in this menu selection is to EXIT, optionally applying an flagging commands to the input data set. The menu looks like: ------------------- | FLAG TIME | To flag single visibility points | FLAG TIME RANGE | To flag all data in a range of times | FLAG AREA | To flag a rectangular area in the flux-time plane | FLAG ABOVE | To set a lower limit and flag all data above over a selected range of times | FLAG BELOW | To set an upper limit and flag all data below over a selected range of times | FLAG ABOUT MEAN | To set a time range within which the mean and rms are determined and then flag all data outside the range MEAN +/- x * RMS, where the user is asked to specify x and to confirm the flagging. | FLAG INTERACTIV | To define a piecewise-linear curve and then flag all data above or below it | FLAG ALL TIME | To flag all times in all frames at once | LIST FLAGS | To list selected range of flag commands | UNDO FLAGS | To remove flags by number from FC table and undo that flagging in the data | SHOW AMPLITUDE | To reload the TV displaying amplitudes | SHOW PHASE | To reload the TV displaying phases | SHOW DECORRELAT | To reload the TV displaying decorrelation index | SELECT FRAME | To select the visibility set to be displayed interactively from the top plot | FIRST FRAME | To display the first set of visibilities | NEXT FRAME | To display the next set of visibilities | PREVIOUS FRAME | To display the previous set of visibities | SELECT BASELINE | To display a new baseline by entering the desired antenna pair on the terminal | NEXT BASELINE | To display the first set of visibilties from the next baseline | PREV BASELINE | To display the first set of visibilties from the previous baseline | LOAD | To reload the TV with the current flags and parameters, checking the scale | EXIT | To resume AIPS and, optionally, enter the flags in the data ------------------- Before the flags are entered in the data, IBLED asks the user whether or not he actually wishes to do this. You must respond yes or no. If the master file is not cataloged (DOCAT <= 0), then your flags will be lost if you do not say yes. If the master file is cataloged and you intend to do more flagging on this particualr set of data, then you should answer no. Then, you can resume later without having to compute a new master file and will have the option to undo previous IBLED flag commands. Once the flags are applied to the input data set, they are much harder to undo and the master file is destroyed since it no longer accurately represents the input data. The subject of Stokes flags deserves more discussion. In their simplest form, they are a string of four 1's and 0's with the 1's represeenting the correlators to be flagged and the 0's those that are not altered. These strings always represent correlators in their basic groupings and orders - I/Q/U/V or RR/LL/RL/LR or XX/YY/XY/YX - even if the current data set only has, say, LL data. IBLED allows you to enter Stokes flags in this form, but also allows more mnemonic forms as well. If I, Q, U, and/or V data are displayed, then the strings i, Q, U, V, IQU, IQUV, and IV are also accepted. If RR, LL, RL, and/or LR data are displayed, then the strings RR, LL, RL, LR, HALF, NOLL, NORR, RRLL, and RLLR are accepted (HALF = RRLL = 1100, NOLL = 1011, NORR = 0111). If XX, YY, XY, and/or YX data are displayed, then the strings XX, YY, XY, YX, HALF, NOYY, NOXX, XXYY, and XYYX are accepted (HALF = XXYY = 1100, NOYY = 1011, NOXX = 0111). FULL is always accepted as 1111. Inside IBLED, these strings apply to the Stokes form(s) chosen for editing and display, which, because of the STOKES input adverb, are not necessarily those of the input data set. If they are of different forms then a translation must take place. The only such translation that is likely to occur is when the user edits in I/Q/U/V a data set in RR/LL/RL/LR. In this case, any flag of I and/or V flags both RR and LL and any flag of Q and/or U flags both RL and LR. IBLED attempts to support the other translations as well. ----------------------------------------------------------------