[daip] New Ticket - [!WEG-138951]: combining D and C array data in the UV plane

[Danielle M Lucero]

New Ticket: combining D and C array data in the UV plane

I have two calibrated HI data sets which I would like to combine before continuum subtraction.  These sets are:

(1) AM874: C array data: 31 channels of width 20.81 km/s for a total bandwidth of 645.11 km/s; Center velocity 1464.456 km/s  (Archive data)

(2) AY161: D array data: 63 channels of width 20.78 km/s for a total bandwidth of 1309.14 km/s; Center velocity 1210.000 km/s (My data)

M87 is in the field of these observations.  It is fairly easy to remove the continuum due to M87 in the D array data, but very difficult in the C array data as M87 lies far outside the primary beam.   

It is not possible to manipulate either or both of the data sets so that they will have he same number of channels of equal width.  This is because of the bandwidth difference.  Does this make it impossible to combine them in the UV plane? 

Also, the center frequencies/velocities are not the same.  I could run CVEL on the C array data.  This would effectively fix the center velocity of that data set to channel 28 instead of channel 16 (I think).  I have actually tried these various things and then tried running DBCON.  I continuously get an error message which says that the frequency data bases are not compatible.  Do you know of a better/correct method?

Perhaps I should just fight with the M87 radio continuum subtraction in each set and then combine in the image plane later? I have in my position a deep D Array continuum image of M87 (observations are centered on M87).  Should I just use clean components from that image to try and subtract the continuum?  

Danielle Lucero

Ticket Details
===================
Ticket ID: WEG-138951
Department: AIPS Data Processing
Priority: Default
Status: Open
Link:  https://help.nrao.edu/staff/index.php?_m=tickets&_a=viewticket&ticketid=785