[daip] [!8690]: AIPS - Factor in CONVL

[Hansung Gim]

Hansung Gim updated #8690
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Factor in CONVL
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           Ticket ID: 8690
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/8690
           Full Name: Hansung Gim
               Email: hgim at astro.umass.edu
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): -- Unassigned --
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 18 July 2016 06:41 PM
             Updated: 18 July 2016 06:41 PM
                 Due: 20 July 2016 06:41 PM (2d 0h 0m)
      Resolution Due: 26 July 2016 06:41 PM (8d 0h 0m)



Dear a related person

  I am trying to convolve the image with larger Gaussian beam. When I look at the explanation of CONVL, it is described that "factor" should be set (new beam area)/(old beam area). My original image has a beam size of 1.47"x1.42". I would like to convolve this with the Gaussian of beam size 6"x6". I set the factor of 17.25 (=6x6/(1.47x1.42)). However, I have seen that the RMS noise of the new image goes up by a factor of 3. As I understand, the convolution with the larger beam size makes the RMS noise go down. I think, there are something I have missed. Could you let me know what factor should be ? 


Best Wishes,
Hansung Gim



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