[alma-config] Compact heterogeneous arrays

[Min Yun]

My worry exactly, but someone might insist on cross-correlating the
small dishes with larger ones -- I can argue both ways.  Exactly
what the ultracompact array is and what its intent and operation needs
are to be better defined.  For example, should they be reconfigurable?
If not, we could just stick them in the middle of the current 
configuration designs, perhaps on a higher pedestal as you suggeste.
If it were to operate as an independent high frequency array, then
it would make sense to place it physically apart from the main array.

I would like to raise this issue at the
ASAC meeting this week, and I would like to ask Morita-san to
give a presentation at the Tucson meeting concerning this
concept.  If Morita-san can give us an early preview as what the
current concept is, that might help us to work out some of the
details in advance.




					-- Min

p.s. If such an array is part of ALMA, surely this will require a
subarray capability of its own at all times, and this means the
standard operation mode of ALMA would be at least 3 subarrays at
all times, with 4 or 5 subarray operation quite often.  This has
a major implication to the to the system design, and this needs
to be communicated clear to the rest of the project!


> Message-ID: <85AB8CB6EF94D211BC8400105AA28F2918F09E at MERCURY.roe.ac.uk>
> From: Adrian Webster <asw at roe.ac.uk>
> To: "Alma Config (E-mail)" <alma-config at cv3.cv.nrao.edu>
> Subject: [alma-config] Compact heterogeneous arrays
> Date: Mon, 6 Mar 2000 15:41:21 -0000 
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> I think that if there is to be an array of small dishes, perhaps half the
> size of the main 12m ALMA dishes, they cannot possibly be sited in with the
> compact configuration for the larger dishes. Quite apart from likely
> incompatibilities in the stations, the smaller dishes will surely stand only
> half as high above the ground and will be heavily shadowed by their large
> neighbours. The two types of compact configuration will have to be sited
> some distance apart.
> 
> ...........................................
> 
> Adrian Webster,
> Institute for Astronomy,
> Department of Physics and Astronomy,
> University of Edinburgh,
> Royal Observatory,
> Blackford Hill,
> Edinburgh EH9 3HJ,
> Scotland.
> asw at roe.ac.uk
> tel: 0131-668-8391
> fax: 0131-668-8416
> 
> ...........................................
>