[mmaimcal]Re: reconfiguring

[John Conway]

Hi,

 There is a question of how much flexibility in response
to proposal pressure one wants.  I myself was never 
a fan of changing the scheduling scheme on a week 
to week basis in response to proposal pressure.
In my memo 283 I present what I had in mind. I
considered that there would be differnt types of
expt, some requiring an exact resolution others with 
looser requiements the more exacting ones would 
be scheduled first. In this way in a zoom array you 
could get the option of exactly the same resolution 
at different line transitions  (which you didn't have 
with fixed  arrays 2 or 3 apart in resolution). 
The felxibility in sheduling was based on -WHEN-
a experiment was scheduled in the move 
schedled, NOT by changing the move schedule 
itself.

I was thinking that one MIGHT  change the overall
cycle scheme every cycle or two in response to 
the statistics of proposals pressure, Thus if 
after 9 months or 18months it seemed that the statitsics
showed a   certain array size was less popular then 
for the coming 9 month schedule one would schedule there 
to be  2 moves days our of every 3 through 
that array size rather than 1 out of every 3  
- and then move slower through the popular arrays, while 
maintaining the overall cycle time - something like that.
Even in this scheme I did not envision allowing the whole 
configuration cycle time to be ajustable in 
reponse to proposal pressure. I think it would 
be good to consider the overall cycling with repect to 
seasons, try to optimise it and then keep it fixed
no matter how much internal flexibilty is 
introduced within the cycle.

Of course if people think it would be desirable to 
have more interaction between proposal pressure and the 
reconfiguration cycle- then I guess it can be built in but 
it gets complicated fast.

   John









On Wed, 11 Dec 2002, Mark Holdaway wrote:

> 
> 
> > > how can we make a reconfiguration scheme which will
> > > be flexible enough to respond to changes in proposal pressure,
> > > while maintaining certain properties we are happy with
> > > (ie, seaonal cycling).
> > 
> > yep - this is the key.  but, i don't know that we have to make a scheme
> > to begin with that is necessarily flexible intrinsically.  the
> > flexibility is built into the pad layout, in many ways, which was
> > the big reason (in my mind, at least) why the 'zoom-spirals' won out
> > over the nested donuts...
> > 
> 
> A principle which can guide flexibility:
> 
> to let the time spent in each configuration be proportional to observing
> pressure (or high quality observing pressure).
> 
> We have two knobs to turn:
> 	- speed of reconfiguration
> 	- amount of time spent on end points
> 
> We start with OUR reconfiguration scheme (whatever that is), and
> then adjust the two knobs in responce to proposal pressure, perhaps
> in a week-by-week decision process (ie, if there is a large backlog
> of projects, the site director could choose to slow down 
> reconfiguration; if there are gaps in ALMA's use because there are no
> projects at that LST and that resolution and those prevailing weather
> conditions, it is time to move antennas faster).
> 
> If this flexible approach is chosen, then we have no reproducable cycling 
> through seasons, it just comes out the way it comes out.... and we may
> move faster through summer than winter.
> 
>    -Mark
> 
> 
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