[daip] [!15876]: AIPS - How to change antenna weight with the AIPS task "WTMOD" ?

[NRAO Helpdesk]

Drew Medlin updated #15876
--------------------------

          Department: AIPS Data Reduction (was: General Queries)
       Staff (Owner): Amy Mioduszewski (was: -- Unassigned --)

How to change antenna weight with the AIPS task "WTMOD" ?
---------------------------------------------------------

           Ticket ID: 15876
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/15876
                Name: Cheng-Yu Kuo
       Email address: cykuo at mail.nsysu.edu.tw
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): Amy Mioduszewski
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template group: Default
             Created: 19 March 2020 06:34 AM
             Updated: 19 March 2020 06:34 AM
           Reply due: 23 March 2020 06:34 AM (3d 22h 11m)
      Resolution due: 13 December 2022 05:00 PM (999d 9h 37m)
        Dear Dr. Greissen :
    This is Chengyu Kuo from Taiwan. I am currently working on calibrating EHT data with AIPS. In our present approach of polarization leakage calibration in the EHT collaboration, we attempt to downweigh (or increase the weight) the ALMA visibility data by a factor of 10 to 100 before running LPCAL to solve for D-terms. I try to do so with the AIPS task "WTMOD". However, with the information provided by the help file, I still could not be fully sure what I am doing is correct. For example, if I want to set the weights to be one for antennas except for ALMA, and we want to downweigh ALMA by a factor of 10, what I am doing now is to set ANTWT in WTMOD to be ANTWT 0.1 1 1 1 1 1 (we have six antennas for leakage calibration). Is this correct ?   
   The helpfile information for the ANTWT parameter is a bit hard to understand. In particular, the meaning for "weight_out" is obscure to me. Could you please clarify what this parameter does and how we can actually downweigh the visibility data for a particular antenna in the way we attempt ?  Thank you !
regards
chengyu   


------------------------------------------------------
Staff CP:  https://help.nrao.edu/staff
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listmgr.nrao.edu/pipermail/daip/attachments/20200319/3dc8bcc9/attachment.html>