[daip] [!8047]: AIPS - Polarization calibtation of ancient/archival L-band data in AIPS

[James Higdon]

James Higdon updated #8047
--------------------------

Polarization calibtation of ancient/archival L-band data in AIPS
----------------------------------------------------------------

           Ticket ID: 8047
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/8047
           Full Name: James Higdon
               Email: jhigdon at georgiasouthern.edu
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): -- Unassigned --
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 15 February 2016 09:28 PM
             Updated: 15 February 2016 09:28 PM
                 Due: 17 February 2016 09:28 PM (2d 0h 0m)
      Resolution Due: 23 February 2016 09:28 PM (8d 0h 0m)



Dear Helpdesk,

      I am trying to measure polarization at L-band using archival (1995) data. Naturally, I'm using AIPS for the task. I have followed the Cookbook's suggestions to the letter (including Appendix A.2): Normal antenna based calibration (SETJY, VLACALIB, GETJY, VLACLCAL)
followed by a 3-step polarization calibration dance:  a) PCAL using 3C138,  b) RLDIF, and c) CLCOR, where I had just previously entered the tabulated E-field polarization PA for 3C138 (i.e., AIPS> j=1:20;clcorp(j)=-18 - clcorp(j);end).  

     Following the Cookbook, I am instructed to apply the position angle correctios *only* to the left-circular polarization, i.e.,

AIPS 1: CLCOR     Task which applies various corrections to CL tables.
AIPS 1: Adverbs     Values                 Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: INNAME     'N3646-CD'              Input UV file name (name)
AIPS 1: INCLASS    'L BAND'                Input UV file name (class)
AIPS 1: INSEQ         1                    Input UV file name (seq. #)
AIPS 1: INDISK        1                    Input UV file disk unit #
AIPS 1: SOURCES    *all ' '                Source list ' '=>all.
AIPS 1: STOKES     'L'                     Stokes type to process
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           1                    Lowest IF number 0=>all
AIPS 1: EIF           1                    Highest IF number 0=>all
AIPS 1: TIMERANG   *all 0                  Time range to use.
AIPS 1: ANTENNAS   *all 0                  Antennas to correct.
AIPS 1: SUBARRAY      0                    Subarray;  0 => 1.
AIPS 1: GAINVER       0                    Input CL table 0=>high
AIPS 1: GAINUSE       0                    Output CL table: not =
AIPS 1:                                    GAINVER -> high+1
AIPS 1: OPCODE     'POLR'                  Operation code.
AIPS 1: CLCORPRM     54.0659     79.1149   Parameters (see HELP CLCOR).
AIPS 1:             -18         -18         -18         -18
AIPS 1:             -18         -18         -18         -18
AIPS 1:             -18         -18         -18         -18
AIPS 1:             -18         -18         -18         -18
AIPS 1:             -18         -18
AIPS 1: BADDISK    *all 0                  Disks to avoid for scratch
AIPS 1: INFILE     *all ' '                OPCODE = 'ANTP' or 'ANTC':
AIPS 1:                                     list of times and relevant


------------------------------------------------------
Staff CP:  https://help.nrao.edu/staff