[alma-config] Re: simulation

[morita]

Dear Leonia,

thank you for your comments about my simulations.
 
> 1. I suppose that your simulation does not include mosaic. If it does then
>    skip this comment.
>    You consider the case when the image(model) size is bigger than the primary
>    beam. Of cource the big effect of the antenna pointing error can be expected
>    at this case.
>    On the other hand if the image(model) size is bigger than the primary
>    beam than mosaic should be used. So this case is not practical for
>    the single pointing observation.

Yes, my simulations are not for mosaicing observations.
As I wrote in the report, it is often the case that source sizes 
are comparable to or a little bit larger than the primary beam for 
many observations with the Nobeyama Millimter Array for example.  
That is because mosaicing observations are time consuming job.

Anyway, I am conducting similar simulations using different source model
of which size is less than FWHM of the primary beam.  I am getting
similar
results and maybe I can tell you about these results in next week.

> 
> 2. The synthesyzed beam given at figure 5 shows negative side lobes as big
>    as ~10%. This looks strange for me. I shown in my paper that negative side
>    lobes can not be more than 1/(N-1) for snapshot observation and for
>    natural weighting, where N is number of antennas. I think they should be
>    even less for non snapshot observation.
>    May be you do not use natural weighting?

I am using the uniform weight, because we often use it for high 
S/N cases to get better resolution.  
I will do with the natural weight also.  
But, to do this, I must expand the size of the spiral array about 
25-30 %, because the beam width of the synthesized beam with the 
natural weight is 25 - 30% wider than that with the uniform weight 
for the spiral array.  
For the ring array, those are almost same.
I think this is one of good characteristics of the ring array.

Regards,
Koh-Ichiro