[alma-config] pointing error

[Leonia Kogan]

HI,

I have carried out the simmulation of observations of two different
classes of sources (cluster of compact sources and expanded source-M51)
with two configurations (doughnut and ring) with pointing error of the
antennas.

The simmulation confirms the Mark's precaution that pointing error can
aggravate the image quality very seriously.

The result of the simmulation coincides in principle with the Morita's 
simmulation.

Comparing the effect of the pointing error on the image quality for the
two configurations we are coming to the conclusion:

The configuration that gives better image without pointing error remains 
be better with the same pointing error.
 
The pointing error aggravates the image quality more seriously for the
better quality image  without pointing error.

For some sources the difference of the image quality for different
configurations can become very small in presence of the pointing
error.

So the Holdaway's precaution is partially right although there is no inversion. His statement can be paraphrased :

"The pointing error can destroy a difference between configurations in
the sence of the image quality. Take any configuration and get equally
bad image quality."

We can discuss the details of the simmulation.
I am preparing the memo.

Leonia