[daip] IM2UV Size Constraints

[landon at inaoep.mx]

Hi, I'm just wondering if you recieved my email last Thursday, March 3rd as I
have been having problems with my account the past few days. If so, sorry to
bother you. If not, here it is.

Thanks, 
-Landon Halloran






_______________________________________________________________________________

Hi Amy,

 Thank you sincerely for the help! 
 Just to clarify (or possibly complexify) the problem:

      I have a 3x3x512 pixel cube that was made from 9 single-dish observations
 (at (arcseconds w/ reference to central observation)=(-16,-16), (-16,0),
 (-16,16), (0,-16), etc.). Applicable channels of this cube have been averaged
 together in the frequency axis to make a smaller cube that is compatible with
an
 interferometer cube with the same pointing center. I have divided the
 interferometer map by its applicable beam to properly weight longer spacings.
 Now I want to convert my SD map to the UV plane, reweight longer spacings,
 transform back to the image plane, and then combine the SD and IF maps with
 IMERG. This is where the problem arises.
      I must interpolate, with LGEOM, the SD map to dimensions that are a power
 of 2 in order to get IM2UV to work. I interpolated by a factor of 16 (to make a
 map with a pixel size of 1", equal to that of the IF map) and made a 32x32
pixel
 image. This is the image I have sent to you. IM2UV will not operate on this
 image. I have also created a map interpolated by a factor of 64 (128x128pix).
 IM2UV will work on this map; however, I need to cut all spacings longer than
7.4
 kilolambda and only 4 of the resulting visibilities fall in this range. Also,
 they have amplitudes in excess of 50Jy, while the IF visibililities are at
about
 the 1Jy level.
      I'm sure I have sufficiently complexified the problem (sorry!), but
 possibly there is a method I could use to accomplish my goal that bypasses
 IM2UV.

      Any help you have is greatly appreciated!

 Thank a lot,
 -Landon Halloran





 Quoting Amy Mioduszewski <amiodusz at aoc.nrao.edu>:

 > Hi Landon,
 > 
 > Hmmmmmm, maybe it doesn't like the "GLS" axis.  The header looks
 > odd to me but there is no obvious thing that would make IM2UV
 > croak.  I think we are down to you putting the image somewhere
 > that I get it so I can test IM2UV here.  I've done some tests on
 > images I have and IM2UV works fine on them, but they were all
 > produced by AIPS.
 > 
 > Cheers,
 > 
 > Amy
 > 



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