[mmaimcal]Reconfiguration

[John Conway]

> 
> > 4) Are there times of year we definitely 
> > DON'T want to be in the compact or extreme 
> > arrays (the Bolivian winter pehaps) we can schedule 
> > one of the intermediate arrays for this (since they 
> > occur every 4.5 months anyways its not too much loss).
> > If we work such factors in this would argue for 
> > a rational fraction between  cycle time and 1 year 
> > and for a particular phasing of that cycle.
> 
> My opinion: all configurations need to share in the Bolivian
> winter, just as all configurations should share in the good times
> (at this point, you should picture an array of antennas drinking
> vodka and dancing -- don't ask me, I dislike vodka myself).
>

I  don't neccessarily agree that being 
fair to all arrays is the right criteria (but you may be
right but I'm not sure) - a counter argument would be to say  that the 
onjective should be to maximise the science return and that might 
be best served by making sure that the compact array never hits 
the worst of a Bolivian winter. With an exact 9 month schedule as  given
above and 6  weeks in the compact array then we can arrange that we are 
never be in the compact array during any particular 6 week 
period (for instance never between Feb 15 and March 31st, someone
remind me when the Bolivian Winter is please, the exact 6 week 
period to avoid  we can choose of course).


Another  quite seperate argument to the one above (that I made
in my earlier reply) is that  in a zig-zag scheme the  extreme arrays
(compact and Y+ extreme) occur less 
often than the intermediate ones. Having a whole compact 
array wiped out by the Bolivian winter means you must wait 9 months 
to the next compact array. Having some intermediate array wiped 
out you need only wait 4.5 months till it comes around again.


 
> Once I get a scheme for the reconfiguration cycle that we
> are all OK with (a hope), I will manufacture a complete
> dataset of TAU and RMS_PHASE (by filling in the gaps in
> the site testing data by hook or by crook), turn the crank
> to reconfigure for about 3 years, and then look at the
> distributions in TAU and PHASE for each configuration
> and each LST range, basically to verify that EACH
> source and EACH configuration is getting a fair shake.
> 

Sounds good. 

I thought this would be a good subject for ASAC to discuss!
It would keep ASAC busy for a while. Only (half) joking, But its 
good this discussion has  started  - we have put it off 
for too long since we think we can always think about it 
'later' but 'late' is coming sooner and sooner these
days. . The main point is to decide an overall cycle time 
and make 100% certain its consistent with transporter capability
and staffing levels.  If we go for 9 month cycle we should 
tell the Transporter people we want this since it means a 
larger reconfiguration rate than one move day our of every 3 or 4,
which I guess we have been telling them up to now. The rate 
we want should be achieveble with 2 transporters but they should be
informed of our requirements.

   John