[alma-config]reconfiguration order, configuration subsets

[Mark Holdaway]

> Two things we should start to consider in the configuration design.
> Neither should not be left to chance, but rather included from the
> outset and specified as part of the configuration design. 
> 
> 1) In moving from one configuration to another, which specific antennas
> should be moved and in what order?
> 
> 2) ALMA construction and comissioning will take several years. During
> this time, ALMA will conduct interim science operations with a subset of
> the antennas. Under these conditions, which stations should be occupied
> to produce optimum quality images? 

While it is good to think this stuff out in advance, these things will
likely change as we go.

At the VLA, the N-S stretched hybrid arrays were, I believe, an
afterthought discovered in the early days of operation.

(Make your list "Three things", including plans for how to make
N-S stretched hybrid arrays, which will be intimately entangled with
the order of the moves.)

Similarly, the use of the VLA C array with a few of the innermost D array
stations was a new thing.

The Nobeyama, ATCA, and IRAM arrays were built with many pads that
are now NOT used.

So, while I think it is good to design much of the use strategy
at this time, we should be open to unplanned uses of the array.



One other point which we could discuss at this time is a philosophy of
multi-configuration observing (PoMCO -- OK, I'm being silly with the
'nym), which has still eluded us in spite of repeated declarations of its
importance.  But even if we DID have a multiconfiguration use policy, we
likely wouldn't enforce it, except perhaps for trivial things like: "if
multiple configurations are used, their resolutions must differ by at
least a factor of X".  Then again, the main motivation behind a PomCO was
to help in the configuration design process; a PoMCO may be irrelevant at
this point. 

	-Mark