WBR Step 7C: Apply Your Calibration

After you have calibrated your calibrators, you are going to want to apply this calibration to your source data-- the object you actually care about imaging.

First, you need to make a CL table that interpolates the amplitude/phase solutions found every ~30 minutes for the phase calibrator to your source data. You can use CLCAL or VLACLCAL to do this. Let's say your sources are "PHS_CAL' and 'COOL_GAL', and you have a lovely SN table for 'PHS_CAL' which you determined using the steps in Section 6. Then your inputs to CLCAL will look like this:

AIPS 1: CLCAL     Task to manage SN and CL calibration tables
AIPS 1: Adverbs     Values                 Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: INNAME     'NICE_DATA'            Input UV file name (name)
AIPS 1: INCLASS    'L BAND'                Input UV file name (class)
AIPS 1: INSEQ         2                    Input UV file name (seq. #)
AIPS 1: INDISK        1                    Input UV file disk unit #
AIPS 1: SOURCES    'PHS_CAL'              Source list to calibrate
AIPS 1:            'COOL_GAL'  *rest ' '
AIPS 1: SOUCODE    ' '                     Source "Cal codes"
AIPS 1: CALSOUR    'PHS_CAL'              Cal sources for calibration
AIPS 1:            *rest ' '
AIPS 1: QUAL         -1                    Source qualifier -1=>all
AIPS 1: CALCODE    ' '                     Calibrator code '    '=>all
AIPS 1: TIMERANG   *all 0                  Time range to calibrate
AIPS 1: SUBARRAY      0                    Subarray, 0=>all,
AIPS 1: ANTENNAS   *all 0                  Antennas selected, 0=> all
AIPS 1: SELBAND      -1                    Bandwidth to select (kHz)
AIPS 1: SELFREQ      -1                    Frequency to select (MHz)
AIPS 1: FREQID       -1                    Freq. ID to select.
AIPS 1: OPCODE     ' '                     Operation 'MERG','CALI',
AIPS 1:                                    'CALP'; ' ' => 'CALI'
AIPS 1: INTERPOL   '2PT'                   Interpolation function,
AIPS 1:                                    choices are: '2PT','SIMP',
AIPS 1:                                    'AMBG','CUBE','SELF','POLY',
AIPS 1:                                    'SELN'; see HELP for details
AIPS 1: CUTOFF        0                    Interpolation limit in
AIPS 1:                                    time (min); 0=> no limit.
AIPS 1: SAMPTYPE   ' '                     Smoothing function
AIPS 1: BPARM      *all 0                  Smoothing parameters
AIPS 1: ICUT          0.1                  Cutoff for functional forms
AIPS 1: DOBLANK       0                    Blanked value interpolation
AIPS 1: DOBTWEEN      0                    > 0 -> smooth all sources
AIPS 1:                                    together; else separate them
AIPS 1: SMOTYPE    ' '                     Data to smooth
AIPS 1: SNVER         0                    Input SN table, 0=>all.
AIPS 1: INVERS        0                    Upper SN table vers in a
AIPS 1:                                    range.  0=>SNVER
AIPS 1: GAINVER       1                    Input Cal table 0=>high
AIPS 1: GAINUSE       2                    Output CAL table 0=>high+1
AIPS 1: REFANT        8                    Reference antenna 0=>pick.
AIPS 1: BADDISK    *all 0                  Disks to avoid for scratch

Now CL table #2 has all the info you need to calibrate your data!

Next, you want to apply this calibration and split your 'COOL_GAL' data off into a single source file. For this, use SPLIT.

AIPS 1: SPLIT     Task to split multi-source uv data to single source
AIPS 1: Adverbs     Values                 Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1:                                    also works on single files.
AIPS 1: INNAME     'NICE_DATA'            Input UV file name (name)
AIPS 1: INCLASS    'L BAND'                Input UV file name (class)
AIPS 1: INSEQ         2                    Input UV file name (seq. #)
AIPS 1: INDISK        1                    Input UV file disk unit #
AIPS 1: SOURCES    'COOL_GAL'             Source list
AIPS 1:            *rest ' '
AIPS 1: QUAL         -1                    Source qualifier -1=>all
AIPS 1: CALCODE    ' '                     Calibrator code '    '=>all
AIPS 1: TIMERANG   *all 0                  Time range to copy
AIPS 1: STOKES     ' '                     Stokes type to pass.
AIPS 1: SELBAND      -1                    Bandwidth to select (kHz)
AIPS 1: SELFREQ      -1                    Frequency to select (MHz)
AIPS 1: FREQID       -1                    Freq. ID to select.
AIPS 1: BIF           0                    Lowest IF number 0=>all
AIPS 1: EIF           0                    Highest IF number 0=>all
AIPS 1: BCHAN         0                    Lowest channel number 0=>all
AIPS 1: ECHAN         0                    Highest channel number
AIPS 1: SUBARRAY      0                    Subarray, 0=>all
AIPS 1: DOCALIB       2                    > 0 calibrate data & weights
AIPS 1:                                    > 99 do NOT calibrate weights
AIPS 1: GAINUSE       2                    CL (or SN) table to apply
AIPS 1: DOPOL        -1                    If >0 correct polarization.
AIPS 1: BLVER         -1                    BL table to apply.
AIPS 1: FLAGVER       0                    Flag table version
AIPS 1: DOBAND       -1                    If >0 apply bandpass cal.
AIPS 1:                                    Method used depends on value
AIPS 1:                                    of DOBAND (see HELP file).
AIPS 1: BPVER         1                    Bandpass table version
AIPS 1: SMOOTH     *all 0                  Smoothing function. See
AIPS 1:                                    HELP SMOOTH for details.
AIPS 1: OUTCLASS   'SPLIT'                 Output UV file name (class)
AIPS 1: OUTSEQ        0                    Output UV file name (seq. #)
AIPS 1: OUTDISK       0                    Output UV file disk unit #.
AIPS 1: DOUVCOMP     -1                    1 (T) => compressed data
AIPS 1: APARM      *all 0                  Control information:
AIPS 1:                                      1 = 1 => avg. freq. in IF
AIPS 1:                                               multi-channel out
AIPS 1:                                        = 2 => avg. freq. in IF
AIPS 1:                                               single channel out
AIPS 1:                                        = 3 => avg IF's also
AIPS 1:                                      2 = Input avg. time (sec)
AIPS 1:                                      3 > 0 => Drop subarrays
AIPS 1:                                      4 > 0 => calibrate weights
AIPS 1:                                      5 = 0 pass only xc data
AIPS 1:                                        = 1 pass xc and ac data
AIPS 1:                                        = 2 pass only ac data
AIPS 1:                                      6 > 0 add full source name
AIPS 1:                                            to header
AIPS 1: NCHAV         0                    Number of chan. to average.
AIPS 1:                                    (used if APARM(1) = 1)
AIPS 1:                                    <= 0 -> ALL
AIPS 1: CHINC         0                    Channel incr. between output
AIPS 1:                                    channels (used if APARM(1)=1)
AIPS 1: ICHANSEL   *all 0                  Array of channel start, stop,
AIPS 1:                                    and increment numbers and IF
AIPS 1:                                    number to be used when
AIPS 1:                                    averaging in frequency.
AIPS 1:                                    (used if APARM(1) = 2, 3)
AIPS 1: BADDISK    *all 0                  Disks to avoid for scratch

The most important things to have set here are DOCAL = 2 and GAINUSE=2. If you have done other fancy things like a baseline-dependent calibration or a bandpass calibration, you can also apply those here.

SPLIT will make a file with just the calibrated data for your source of interest. You'll need to flag this single-source file, and then you'll be ready to image!