[daip] UVCON problem

[Leonia Kogan]

Niruj,

Before I run UVCON with your inputs and data let me give you some advises:

1.Use CMETHOD='GRID' if you use image as input model
   It may not be so crucial
2.Use DOSDIMAG=0, if you do not want to consider W term
   It is not crucial but...
3.You write the result is not sensible. To say if result is sensible or 
not, I'd restore the image using UVCON calculated UV data (using IMAGR 
at AIPS for example) and compare it with the model.
4. Pay attention that UVCON does not pay attention on Dec of the model 
given at the model image. Instead UVCON put the model into declination 
given at aparm(3). Actually this is a good feature of UVCON
5. XY must be at the right hand coordinate system, although it may be 
wrong at the light of recent change to match with UVMOD :)


And finally the error which I see at the input file:

YOU IGNORE THE FIRST COLUMN, (as I see at the file LOFAR2010) which 
determines the coordinate system corresponded to the following X,Y,Z...
Even if your XYZ are given at the equatorial coordinate system (the 
first column=0) you must put '0' into the first column but not blank!!!!
I guess your XYZ are given at the local horizon coordinate system (z=0)
Therefore the first column must be equal '1'

Leonid Kogan




Niruj Mohan Ramanujam wrote:
> 
> 
> Hi,
> 
> I am trying to create a uv dataset from an external image using UVCON 
> and the result didnt seem sensible. Hence I made an image which is a 
> single point source (in one pixel) with noise and that has problems too. 
> In summary
> 
> I have attached the input antenna file, UVCON input, the input image, 
> and the UVPL outputm which is obviously crazy.
> 
> 1. If i run UVCON with a SMODEL =1,0, it runs perfectly well and gives 
> me sensible uv data
> 2. If I input the image, even if the flux is only in one pixel, and i 
> changed the cdelt to 0.1", with the uv data resolution being >6", I 
> still get very strange uv data.
> 
> Can you please let me know if I am doing something wrong or is there a 
> bug ?
> 
> regards
> Niruj
> 
> 
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