[alma-config] Compact heterogeneous arrays

[morita]

Dear Min,

yes, Japanese comunity is still discussing to built
smaller dishes for a ultra compact array.
But, according to current discussion in LMSA advisory 
committee, the first priority of our contribution to 
enhanced ALMA is to make a number of 12 m antennas.  
Due to limitation of human power and budjet, it would be 
difficult to design and to build both 12 m dishes and 
8 m dishes, simultaneously.  Ishiguro san is still
searching some possibility to make 8 m dishes on same
antenna mount of 12 m dishes.  But, he said it is
still not easy to do.

Maybe, this discussion will continue for a while in
several meetings (ALG, ASAC, LMSA advisory committee ...).
At the moment, I am not sure I can show you any Japanese 
definite plan of the ultra compact array.

About the merits of such a ultra compact array, Al showed
us a good summary in his email.   People in Japanese 
comunity want to see more realistic simulations.
It is important to compare mosaicing imaging of homogeneous
array + single dish image with that of heterogeneous array
+ single dish including antenna pointing errors, beam
shape errors, etc.

I am now in Tucson and just preparing to make such 
simulations with Mark Holdaway.  But, we have only 
2 weeks until the Tucson meeting, so, it is difficult to
show you some results ....

Koh-Ichiro