[daip] [!7044]: AIPS - Old VLBA/Global VLBI data formats

[NRAO Helpdesk]

Data Analysts updated #7044
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          Department: AIPS Data Reduction (was: VLA/GBT/VLBA Archive and Data Retrieval)
       Staff (Owner): Amy Mioduszewski (was: Data Analysts)

Old VLBA/Global VLBI data formats
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           Ticket ID: 7044
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/7044


Dear support,
I am interested in re-calibrating some old VLBI data of the galaxy Arp 220. I found two projects, GL015 and GL021 in the archive which would be interesting to calibrate. The data contain both continuum data as well as "zoom line IFs" correlated with higher spectra resolution to image masers. I have calibrated later data as well, and in those cases there has been one UVFITS file in the archive containing all continuum data, which is what I am interested in. However, for these old epochs I find about a 100 different files in the archive. I tried downloading these and reading them into AIPS with concatenating in FITLD. It works partially, but gets a bit messy with data split in different files, which then has to be combined in different ways in AIPS. Before I spend too much time down this road, I wanted to ask: is there any easier way to handle these old data? Or, is there a guide somewhere for what tasks to run to get the data in the proper order? So far, AIPS has made me touch FITLD, SPLIT, VBGLU, MATCH, MULTI, DBCON etc. just to load the data. While it looks good in some ways, I'm sceptical about the result in other ways, so I thought I better ask to see if there is some common wisdom regarding these old data, or if I'm on my own experimenting with AIPS tasks. 

Best regards,
Eskil, PhD candidate

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