[mmaimcal]New System Design Description

[Al Wootten]

Folks,

There is a new version of the System Design Description available from Larry.  
Please read it over.  The next Science IPT telecon will be held on 13 January.
Since the ALMA Change Control Board will be meeting at 1530 UT we will have to hold
our telecon a little earlier, with apologies to the West Coast US members.  Let us
schedule the telecon for 1430 UT.

Larry D'Addario announced:
A revised version of the System Design Description document is
available on ALMAEDM at

/IPTs /SystemEngineering /Documentation .
or directly:

http://almaedm.tuc.nrao.edu/forums/alma/dispatch.cgi/docsyseng/showFile/100534/d20031222222940/No/systemDescription.pdf

This is rev B, document 80.04.00.00-002-B, dated 2003-12-15, and is no
longer considered a "draft."  (On the index page, it is incorrectly
shown as -A and the title still calls it "draft only" because the
system does not permit me to change the document number, title, or
date.  I hope this will be fixed soon.)
The major changes from the previous version (dated 2003-09-10)
include:

. Sec 2.6 "Correlation" (mainly 2.6.1) and Table 3 revised to reflect
the adoption of a tunable digital filter bank in place of the single
programmable filter for each input channel.  This is a major design
change.  In addition, the description of delay tracking should now be
correct (I hope).

. Sec 3.1.1.2 "Phase Accuracy" and Table 4B revised substantially.
The numerical values listed as "current requirements" are still not
final, but they should be quite close.  The basis for them is given
much more clearly, with references cited for further information.  I
thank Mark Holdaway for extensive simulation work that has enabled
this to be understood more fully than before.

. Sec 3.2 "Control and Monitoring" has had a few clarifications added
and typos fixed.

. Sec 4.5 "Synchronization" has been partly re-written for better
clarity and some implementation principles have been added.

. Ran a spelling check throughout, and made various minor
corrections.  Filled in nearly all missing numbers, removing "??"
flags.

I cannot claim that this version is entirely correct or complete, but
I think it is good enough to be taken seriously.  Please advise me of
any errors or omissions that you notice.

--Larry