[mmaimcal]Re: reconfiguring

[Al Wootten]

Hi Min

I'll try to do this for the MMAImCal meeting next week, where we
can discuss this.  That way, it will be on a WWW page and easily
accessible by all (and findable in my office).

Al

Min S. Yun writes:
 > Hi Gang,
 > 
 > Most of these issues were discussed at some level before, and
 > it is interesting which idea has survived the test of time.
 > My recollection as an early participant in this work and as an
 > ASAC observer is that the reconfiguration cycle time discussed
 > in the past (at least when the configuration style and reconfiguration
 > modes were being decided) were shorter. There were discussions of 
 > going to Y+ configuration only every other times or so, because of the
 > large overheads in the reconfiguration, etc.  
 > 
 > I don't think the whole ASAC would care to look at all these e-mail
 > exchanges, but I suspect many members of ASAC have an opinion on 
 > this.  If someone can put together a straw reconfiguration plan
 > and a summary of the relevant discussions (e.g. Bolivian winter),
 > I would like to forward it to the ASAC and hear some of their voices.
 > What do you think, Al?
 > 
 > 
 > 					-- Min
 > 
 > -----------
 > 
 > Min S. Yun				e-mail: myun at astro.umass.edu
 > Assistant Professor			phone:  (413) 545-2215
 > Astronomy Department			FAX:    (413) 545-4223
 > University of Massachusetts             http://www.astro.umass.edu/~myun
 > Amherst, MA 01003
 > 
 > 
 > 
 > On Fri, 13 Dec 2002, John Conway wrote:
 > 
 > > 
 > > Hi,
 > > 
 > > On Thu, 12 Dec 2002, Al Wootten wrote:
 > > 
 > > > I think we all agreed with a cycle of less than a year, so if Fred makes
 > > > that decision it will be because he had good advice.
 > > > 
 > > > Al
 > > 
 > > 
 > > Hi,
 > > 
 > > (1)  Yes I think with a cycle time of 9 months you get 
 > > quite good properties, the time to cycle the seasons
 > > is 3 years, so 18 months to go to being the  opposite season 
 > > - but since the compact array and most extended arrays 
 > > are of order 6 weeks long, the time between the end 
 > > of one compact array and the start of another is 7.5months
 > > (similiary for the most extended array), so you get an approximate 
 > > shift  from day to night observations for your favorite 
 > > source on the shortest possible timesclale.
 > > 
 > > (2) A year can be divided into 8 periods of 6.5 weeks 
 > > With an exact 9 month schedule, the compact array 
 > > only every occurs in 4 out of these 8 calendar periods.
 > > (similary for the most extended array)
 > > This can be used to advantage if there were periods 
 > > of order 6.5 weeks long one wanted to avoid for 
 > > particular arrays.
 > > 
 > > If on the other the 
 > > object is to give every configuration a 'fair shake'
 > > and sample all parts of the year equally then you would like to advance
 > > the cycle by about 6.5 weeks over 3 years, so a cycle period of around 41
 > > weeks would accomplish this. This would ease transporter
 > > load but it would then be longer between end of a compact array 
 > > and the start of one (35 weeks) but still give some day/night
 > > cycling within a single year.
 > > 
 > >   John
 > > 
 > > 
 > > 
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